Q.1 What is the primary function of interleukin‑6 (IL‑6) in the immune system?
Activate B cells to produce antibodies
Stimulate the acute‑phase response in the liver
Suppress natural killer cell activity
Inhibit T‑cell proliferation
Explanation - IL‑6 is a pro‑inflammatory cytokine that signals the liver to produce acute‑phase proteins such as C‑reactive protein during inflammation.
Correct answer is: Stimulate the acute‑phase response in the liver
Q.2 Which cytokine is known as the key mediator of the cytokine storm seen in severe COVID‑19 cases?
IL‑10
IL‑4
IL‑1β
IFN‑γ
Explanation - IL‑1β is a potent pro‑inflammatory cytokine that can be massively released during a cytokine storm, contributing to severe inflammation.
Correct answer is: IL‑1β
Q.3 A microelectrode array is used in immunotechnology to measure which property of immune cells?
DNA sequencing
Cell membrane potential
Cytokine secretion rates
Mitochondrial ATP production
Explanation - Microelectrode arrays can detect changes in local electrochemical signals produced by cytokine secretion, enabling real‑time monitoring of immune responses.
Correct answer is: Cytokine secretion rates
Q.4 Which of the following cytokines is primarily produced by regulatory T cells (Tregs) to suppress immune responses?
IL‑2
IL‑17
IL‑10
TNF‑α
Explanation - IL‑10 is an anti‑inflammatory cytokine secreted by Tregs that downregulates immune activation and promotes tolerance.
Correct answer is: IL‑10
Q.5 In impedance spectroscopy of immune cells, what does a decrease in cell membrane capacitance typically indicate?
Cell apoptosis
Cell proliferation
Increased cytokine secretion
Enhanced phagocytic activity
Explanation - Apoptotic cells lose membrane integrity, reducing capacitance. This change is detectable by impedance measurements.
Correct answer is: Cell apoptosis
Q.6 Which cytokine is a hallmark of the Th2 immune response?
IL‑12
IFN‑γ
IL‑4
IL‑23
Explanation - IL‑4 promotes differentiation of naïve T cells into Th2 cells, which are involved in humoral immunity.
Correct answer is: IL‑4
Q.7 A biosensor that uses a graphene field‑effect transistor (GFET) to detect IL‑2 in blood samples relies primarily on which principle?
Faraday rotation
Surface plasmon resonance
Charge transfer modulation
Thermal conductivity change
Explanation - Binding of IL‑2 to antibodies on the graphene surface changes the local charge environment, modulating the GFET current.
Correct answer is: Charge transfer modulation
Q.8 Which cytokine is involved in the differentiation of Th17 cells?
IL‑21
IL‑2
IL‑4
IL‑5
Explanation - IL‑21, along with IL‑6 and TGF‑β, drives the differentiation of Th17 cells that produce IL‑17.
Correct answer is: IL‑21
Q.9 What role does tumor necrosis factor‑α (TNF‑α) play in the context of autoimmune diseases?
It promotes tissue repair
It induces apoptosis of autoantibody‑producing B cells
It amplifies inflammatory signaling pathways
It suppresses cytokine production
Explanation - TNF‑α is a key pro‑inflammatory cytokine that activates NF‑κB and other pathways, contributing to chronic inflammation in autoimmune conditions.
Correct answer is: It amplifies inflammatory signaling pathways
Q.10 A lab engineer is designing an impedance‑based immunosensor for IL‑1β. Which frequency range is most suitable for detecting cytokine binding events?
0–10 Hz
10–100 Hz
1–10 kHz
100–1 MHz
Explanation - Impedance changes due to cytokine binding typically occur in the kHz range; lower frequencies are dominated by bulk solution effects.
Correct answer is: 1–10 kHz
Q.11 Which cytokine is predominantly secreted by mast cells during an allergic reaction?
IL‑33
IL‑5
IL‑13
IL‑2
Explanation - IL‑13 is a mast cell‑derived cytokine that contributes to IgE class switching and smooth muscle contraction in allergies.
Correct answer is: IL‑13
Q.12 In electrochemical impedance spectroscopy (EIS), what does an increased semicircular diameter in the Nyquist plot indicate about the biosensor’s interface?
Higher charge transfer resistance
Lower double‑layer capacitance
Improved electron transfer
Reduced electrode fouling
Explanation - A larger semicircle in a Nyquist plot corresponds to increased charge transfer resistance, often due to blocking layers or decreased binding efficiency.
Correct answer is: Higher charge transfer resistance
Q.13 What is the main source of interleukin‑17 (IL‑17) in the immune system?
B cells
Th17 cells
Macrophages
Neutrophils
Explanation - IL‑17 is a signature cytokine produced mainly by Th17 cells and plays a key role in recruiting neutrophils to sites of infection.
Correct answer is: Th17 cells
Q.14 Which cytokine is critical for the activation of macrophages and is produced by Th1 cells?
IL‑4
IL‑12
IFN‑γ
IL‑10
Explanation - IFN‑γ, secreted by Th1 cells, activates macrophages to increase phagocytosis and antigen presentation.
Correct answer is: IFN‑γ
Q.15 What is the typical effect of IL‑10 on dendritic cell function?
Enhances antigen presentation
Inhibits cytokine production
Promotes maturation and migration
Stimulates T‑cell proliferation
Explanation - IL‑10 is an anti‑inflammatory cytokine that suppresses IL‑12 and other cytokines from dendritic cells, dampening immune activation.
Correct answer is: Inhibits cytokine production
Q.16 Which of the following cytokines is best known for its role in promoting B‑cell class switching to IgE?
IL‑4
IL‑2
IL‑21
IL‑15
Explanation - IL‑4 drives class switching in B cells towards IgE, essential for allergic responses.
Correct answer is: IL‑4
Q.17 A researcher uses a quartz crystal microbalance (QCM) to detect IL‑6 binding to an antibody‑functionalized surface. What measurable change indicates successful binding?
Increased resonance frequency
Decreased resonance frequency
Rise in temperature
Change in mass loading only at the surface
Explanation - Binding of IL‑6 increases the mass on the quartz crystal, reducing its resonance frequency.
Correct answer is: Decreased resonance frequency
Q.18 Which cytokine is predominantly released by Th2 cells and promotes eosinophil activation?
IL‑5
IL‑12
IL‑17
IL‑22
Explanation - IL‑5 stimulates eosinophil growth and activation, a hallmark of Th2‑mediated responses.
Correct answer is: IL‑5
Q.19 In the context of electrical impedance sensors, what is a typical application of the Debye length?
To determine the diffusion coefficient of cytokines
To estimate the thickness of the electrical double layer at the electrode surface
To calculate the electron mobility in the bulk solution
To measure the temperature sensitivity of the sensor
Explanation - The Debye length characterizes how far the electric potential decays from the electrode, affecting impedance measurements.
Correct answer is: To estimate the thickness of the electrical double layer at the electrode surface
Q.20 What is the role of IL‑2 in the expansion of T cells?
Induces apoptosis
Inhibits proliferation
Promotes clonal expansion
Differentiates naïve B cells
Explanation - IL‑2 is a growth factor for T cells, stimulating their proliferation during immune responses.
Correct answer is: Promotes clonal expansion
Q.21 Which cytokine is considered a master regulator of the differentiation of Th1 cells?
IL‑6
IL‑12
IL‑10
IL‑4
Explanation - IL‑12 promotes Th1 differentiation by activating STAT4 signaling.
Correct answer is: IL‑12
Q.22 How does a microfluidic impedance biosensor typically detect cytokine binding events?
By measuring changes in fluid flow velocity
By detecting variations in electrical impedance across the microchannel
Through optical absorbance of labeled antibodies
By monitoring temperature changes in the chip
Explanation - Binding of cytokines to antibodies immobilized in a microchannel alters local impedance, which is monitored in real‑time.
Correct answer is: By detecting variations in electrical impedance across the microchannel
Q.23 Which cytokine is primarily responsible for the promotion of neutrophil chemotaxis?
IL‑8
IL‑2
IL‑4
IFN‑γ
Explanation - IL‑8 is a potent chemoattractant for neutrophils, guiding them to infection sites.
Correct answer is: IL‑8
Q.24 What does the term 'cytokine storm' refer to?
A sudden increase in antibody titers
An over‑production of cytokines leading to systemic inflammation
The rapid decline of cytokine levels
A viral mutation affecting cytokine genes
Explanation - A cytokine storm is a hyper‑inflammatory response where cytokine levels rise uncontrollably, causing tissue damage.
Correct answer is: An over‑production of cytokines leading to systemic inflammation
Q.25 Which technique uses a ferroelectric field‑effect transistor (FeFET) to detect IL‑4 with high sensitivity?
Surface plasmon resonance
FeFET‑based label‑free biosensing
Enzyme‑linked immunosorbent assay (ELISA)
Western blotting
Explanation - FeFETs can be functionalized with antibodies to detect IL‑4 via changes in threshold voltage, providing label‑free detection.
Correct answer is: FeFET‑based label‑free biosensing
Q.26 What is the main anti‑inflammatory cytokine produced by macrophages during the resolution phase of inflammation?
TNF‑α
IL‑1β
IL‑10
IL‑6
Explanation - During resolution, macrophages shift to a reparative phenotype secreting IL‑10 to dampen inflammation.
Correct answer is: IL‑10
Q.27 Which cytokine is directly involved in the differentiation of Th9 cells?
IL‑21
IL‑9
IL‑23
IL‑12
Explanation - IL‑9 can act in an autocrine fashion to drive Th9 differentiation from naïve T cells.
Correct answer is: IL‑9
Q.28 When designing an amperometric sensor for IL‑2, which electrode modification would enhance sensitivity?
Coating with gold nanoparticles
Applying a high‑temperature annealing step
Using a thick insulating polymer layer
Eliminating all surface functionalization
Explanation - Gold nanoparticles increase the effective surface area and improve electron transfer, boosting sensor sensitivity.
Correct answer is: Coating with gold nanoparticles
Q.29 Which cytokine is secreted by Th17 cells and promotes autoimmune inflammation?
IL‑12
IL‑17
IL‑4
IL‑10
Explanation - IL‑17 is a hallmark cytokine of Th17 cells that induces inflammatory mediators in target tissues.
Correct answer is: IL‑17
Q.30 In a label‑free biosensor, the detection of IL‑6 is often monitored through what electrical parameter?
Capacitance shift
Temperature rise
Optical absorbance change
Fluorescence intensity
Explanation - Binding events alter the local dielectric environment, leading to measurable capacitance changes in the sensor.
Correct answer is: Capacitance shift
Q.31 What does a high concentration of IL‑10 indicate in a disease context?
Increased bacterial infection
Strong antiviral response
Suppressive immune environment
Elevated oxidative stress
Explanation - IL‑10 is anti‑inflammatory and indicates a shift toward immune suppression, often seen in chronic infections or tumors.
Correct answer is: Suppressive immune environment
Q.32 Which cytokine is a signature marker for allergic asthma?
IL‑13
IL‑2
IFN‑γ
TNF‑α
Explanation - IL‑13 contributes to mucus hypersecretion and airway hyperresponsiveness characteristic of allergic asthma.
Correct answer is: IL‑13
Q.33 What is a primary advantage of using graphene oxide (GO) as a substrate in cytokine biosensing?
High optical absorption
Excellent biocompatibility and high surface area
Strong magnetic properties
Low electrical conductivity
Explanation - GO provides a large, functionalizable surface for antibody attachment, enhancing capture efficiency.
Correct answer is: Excellent biocompatibility and high surface area
Q.34 Which cytokine is essential for the activation of cytotoxic T lymphocytes?
IL‑4
IL‑2
IL‑5
IL‑6
Explanation - IL‑2 is critical for the clonal expansion and activation of cytotoxic T cells.
Correct answer is: IL‑2
Q.35 In the context of electrical bio‑impedance, what does a low impedance value in a lymphocyte imply?
High cell membrane integrity
Cell lysis
Active cytokine secretion
Reduced cell volume
Explanation - Healthy cells present lower impedance due to intact membranes allowing easier current passage.
Correct answer is: High cell membrane integrity
Q.36 Which cytokine is known to inhibit the differentiation of Th1 cells?
IL‑10
IL‑12
IFN‑γ
TNF‑α
Explanation - IL‑10 suppresses Th1 differentiation by inhibiting IL‑12 production.
Correct answer is: IL‑10
Q.37 A magneto‑elastic biosensor for IL‑5 uses which principle to transduce binding events?
Changes in electrical conductivity
Shift in resonance frequency due to magnetic loading
Optical interference patterns
Temperature fluctuation
Explanation - Binding of IL‑5 alters the mass and magnetic properties of the sensor, shifting its mechanical resonance.
Correct answer is: Shift in resonance frequency due to magnetic loading
Q.38 What is the primary function of tumor necrosis factor‑α (TNF‑α) in septic shock?
Promote platelet aggregation
Induce vasodilation and capillary leak
Stimulate antibody production
Decrease cytokine release
Explanation - TNF‑α triggers systemic vasodilation and increases vascular permeability, leading to septic shock.
Correct answer is: Induce vasodilation and capillary leak
Q.39 Which cytokine is a key player in the transition from acute to chronic inflammation?
IL‑1β
IL‑12
IL‑10
IL‑4
Explanation - IL‑10 down‑regulates inflammatory processes, facilitating the shift towards chronic, regulated inflammation.
Correct answer is: IL‑10
Q.40 A microcantilever sensor is used to detect IL‑17. What physical change does the sensor monitor?
Vibrational frequency shift
Thermal expansion
Electrical resistance change
Optical diffraction
Explanation - Binding of IL‑17 increases the cantilever mass, reducing its vibrational frequency, which is measured.
Correct answer is: Vibrational frequency shift
Q.41 What is the main effect of IL‑22 on epithelial cells?
Induces apoptosis
Promotes proliferation and barrier repair
Suppresses cytokine production
Triggers antigen presentation
Explanation - IL‑22 supports epithelial regeneration and strengthens mucosal barriers.
Correct answer is: Promotes proliferation and barrier repair
Q.42 Which cytokine is essential for the differentiation of Th9 cells from naïve T cells?
IL‑6
IL‑21
IL‑9
IL‑12
Explanation - IL‑9 promotes Th9 differentiation, contributing to allergic inflammation.
Correct answer is: IL‑9
Q.43 In an electrochemical immunosensor, the term 'limit of detection' (LOD) refers to what?
Maximum analyte concentration the sensor can handle
Minimum analyte concentration that yields a measurable signal
The time needed to produce a signal
The electrode's operating voltage range
Explanation - LOD is the lowest analyte concentration that can be reliably distinguished from background noise.
Correct answer is: Minimum analyte concentration that yields a measurable signal
Q.44 Which cytokine is crucial for the recruitment of monocytes to inflammatory sites?
IL‑8
IL‑2
IL‑4
IL‑10
Explanation - IL‑8 is a potent chemokine that attracts monocytes and neutrophils to infection sites.
Correct answer is: IL‑8
Q.45 A lab uses a quartz crystal microbalance to detect IL‑1β. What phenomenon causes the frequency shift in this measurement?
Change in mass loading on the crystal surface
Alteration of the crystal’s piezoelectric constants
Temperature fluctuations
Magnetic field influence
Explanation - Binding of IL‑1β increases the mass on the crystal, decreasing its resonant frequency.
Correct answer is: Change in mass loading on the crystal surface
Q.46 Which of the following is a hallmark of Th1 cell responses?
Production of IL‑4
Production of IFN‑γ
Production of IL‑5
Production of IL‑10
Explanation - IFN‑γ is a signature Th1 cytokine that activates macrophages and promotes cell‑mediated immunity.
Correct answer is: Production of IFN‑γ
Q.47 What advantage does a label‑free impedance biosensor offer for cytokine detection?
It requires no antibodies
It eliminates the need for signal amplification
It can measure cytokine concentration in real‑time without labels
It does not respond to temperature changes
Explanation - Label‑free impedance sensors detect binding events via electrical changes, enabling real‑time, label‑free quantification.
Correct answer is: It can measure cytokine concentration in real‑time without labels
Q.48 Which cytokine is secreted by Th17 cells and is involved in psoriatic arthritis?
IL‑17
IL‑2
IL‑4
IL‑12
Explanation - IL‑17 contributes to inflammation in psoriatic arthritis by stimulating pro‑inflammatory mediators.
Correct answer is: IL‑17
Q.49 Which of the following is NOT typically considered a pro‑inflammatory cytokine?
TNF‑α
IL‑1β
IL‑10
IL‑6
Explanation - IL‑10 is an anti‑inflammatory cytokine that dampens immune responses.
Correct answer is: IL‑10
Q.50 What is the main advantage of using gold nanorods in an electrochemical sensor for IL‑12?
High magnetic responsiveness
Large surface area and improved electron transfer
Low optical absorption
Strong fluorescence emission
Explanation - Gold nanorods enhance the electrode’s effective surface area, increasing sensitivity to IL‑12 binding.
Correct answer is: Large surface area and improved electron transfer
Q.51 Which cytokine is a major mediator of allergic rhinitis?
IL‑4
IL‑2
IFN‑γ
TNF‑α
Explanation - IL‑4 promotes IgE synthesis and Th2 differentiation, key drivers of allergic rhinitis.
Correct answer is: IL‑4
Q.52 Which parameter is typically measured in an impedance sensor to infer cytokine binding?
Real part of impedance (Z')
Imaginary part of impedance (Z'')
Phase angle
All of the above
Explanation - All components of impedance (magnitude, phase, real/imaginary parts) can provide information about binding events.
Correct answer is: All of the above
Q.53 What is the role of IL‑23 in the immune system?
Promotes Th17 cell maintenance
Inhibits B cell activation
Induces IL‑10 secretion
Stimulates platelet aggregation
Explanation - IL‑23 sustains Th17 cells and amplifies their production of IL‑17.
Correct answer is: Promotes Th17 cell maintenance
Q.54 Which technique is most suitable for measuring the kinetics of cytokine‑antibody binding on a microfluidic chip?
Surface plasmon resonance (SPR)
Mass spectrometry
X‑ray crystallography
Gel electrophoresis
Explanation - SPR provides real‑time, label‑free measurement of binding kinetics in microfluidic devices.
Correct answer is: Surface plasmon resonance (SPR)
Q.55 What is the effect of IL‑2 on natural killer (NK) cells?
Inhibits their cytotoxic activity
Promotes their proliferation and activation
Induces apoptosis
Suppresses cytokine release
Explanation - IL‑2 is a growth factor that enhances NK cell activation and cytotoxicity.
Correct answer is: Promotes their proliferation and activation
Q.56 Which cytokine is predominantly involved in the regulation of allergic inflammation by blocking Th1 differentiation?
IL‑10
IL‑12
IL‑4
IL‑6
Explanation - IL‑10 inhibits Th1 differentiation, favoring Th2‑driven allergic inflammation.
Correct answer is: IL‑10
Q.57 A biosensor uses a piezoelectric crystal coated with antibodies for IL‑8 detection. The sensor’s readout is based on what?
Change in electrical resistance
Shift in resonance frequency due to mass loading
Fluorescence emission
Temperature variation
Explanation - Binding of IL‑8 increases the mass on the crystal, decreasing its resonant frequency.
Correct answer is: Shift in resonance frequency due to mass loading
Q.58 Which of the following cytokines is most closely associated with the suppression of inflammatory responses in the gut?
IL‑10
IL‑12
IFN‑γ
TNF‑α
Explanation - IL‑10 is a key anti‑inflammatory cytokine that maintains gut mucosal homeostasis.
Correct answer is: IL‑10
Q.59 What is the primary effect of IL‑17 on endothelial cells?
Stimulates nitric oxide production
Induces expression of adhesion molecules
Suppresses cytokine release
Promotes apoptosis
Explanation - IL‑17 upregulates ICAM‑1 and VCAM‑1 on endothelial cells, facilitating leukocyte recruitment.
Correct answer is: Induces expression of adhesion molecules
Q.60 Which cytokine is produced by Th1 cells and is essential for macrophage activation?
IL‑4
IL‑2
IFN‑γ
IL‑10
Explanation - IFN‑γ activates macrophages, enhancing their microbicidal activity.
Correct answer is: IFN‑γ
Q.61 What is a common feature of cytokines that function as chemokines?
They are large proteins
They act on nearby cells to induce chemotaxis
They inhibit T cell activation
They are membrane‑bound only
Explanation - Chemokines guide immune cells to sites of infection or inflammation.
Correct answer is: They act on nearby cells to induce chemotaxis
Q.62 Which of the following is a key component in the design of a microfluidic impedance sensor for cytokine detection?
High‑conductivity electrode material
Large channel volume
Non‑functionalized surface
High ionic strength buffer only
Explanation - Using a conductive material like gold or platinum reduces baseline noise and increases signal fidelity.
Correct answer is: High‑conductivity electrode material
Q.63 Which cytokine is considered a hallmark of the Th2 response?
IL‑12
IL‑4
IL‑17
IFN‑γ
Explanation - IL‑4 is the signature cytokine of Th2 cells, driving humoral immunity.
Correct answer is: IL‑4
Q.64 Which property of a graphene‑based sensor enhances its sensitivity to IL‑2?
High surface area for antibody attachment
Strong optical absorption
High thermal resistance
Large bandgap
Explanation - A large surface area allows more antibodies to bind IL‑2, improving detection limits.
Correct answer is: High surface area for antibody attachment
Q.65 What is the function of IL‑21 in the immune system?
Promotes B cell proliferation and antibody class switching
Induces apoptosis in T cells
Suppresses macrophage activation
Stimulates granulocyte production
Explanation - IL‑21 drives B cell differentiation and enhances antibody responses.
Correct answer is: Promotes B cell proliferation and antibody class switching
Q.66 Which cytokine is primarily associated with the induction of fever during infection?
IL‑1β
IL‑2
IL‑4
IL‑10
Explanation - IL‑1β is a potent pyrogen that stimulates the hypothalamus to raise body temperature.
Correct answer is: IL‑1β
Q.67 What is the main benefit of using a gold‑nanoparticle functionalized electrode for IL‑6 detection?
Improved optical properties
Increased surface roughness for better electron transfer
Higher magnetic susceptibility
Reduced electrode cost
Explanation - Gold nanoparticles increase electrode surface area and enhance charge transfer, improving sensor sensitivity.
Correct answer is: Increased surface roughness for better electron transfer
Q.68 Which cytokine is known for its dual role as both pro‑ and anti‑inflammatory depending on context?
IL‑6
TNF‑α
IL‑10
IFN‑γ
Explanation - IL‑6 can act pro‑inflammatory in acute responses and anti‑inflammatory in chronic settings.
Correct answer is: IL‑6
Q.69 Which of the following statements about cytokine detection using EIS is correct?
Only the magnitude of impedance can be measured
EIS provides information on both magnitude and phase of impedance
EIS is insensitive to changes in membrane capacitance
EIS requires labeling of cytokines
Explanation - EIS captures both real and imaginary parts of impedance, giving a complete picture of sensor changes.
Correct answer is: EIS provides information on both magnitude and phase of impedance
Q.70 What is the typical role of IL‑9 in immune responses?
Stimulating B cell apoptosis
Enhancing mucus secretion and mast cell activation
Inhibiting T cell proliferation
Promoting dendritic cell migration
Explanation - IL‑9 contributes to allergic inflammation by stimulating mucus production and mast cell degranulation.
Correct answer is: Enhancing mucus secretion and mast cell activation
Q.71 A biosensor uses a flexible printed circuit board (PCB) for cytokine detection. What advantage does the flexible substrate provide?
Increased mechanical rigidity
Better conformability to curved biological surfaces
Reduced cost of raw materials
Enhanced optical transparency
Explanation - Flexible PCBs can be wrapped around biological tissues for improved contact and signal acquisition.
Correct answer is: Better conformability to curved biological surfaces
Q.72 Which cytokine is directly responsible for inducing IgE class switching in B cells?
IL‑4
IL‑2
IL‑5
IFN‑γ
Explanation - IL‑4 promotes IgE class switching, a hallmark of allergic responses.
Correct answer is: IL‑4
Q.73 In immunotherapy, what role does IL‑15 play?
It suppresses T cell activation
It promotes natural killer (NK) cell and memory T cell proliferation
It induces apoptosis of tumor cells directly
It blocks cytokine signaling pathways
Explanation - IL‑15 is a growth factor that enhances the expansion of NK and memory T cells, useful in cancer therapy.
Correct answer is: It promotes natural killer (NK) cell and memory T cell proliferation
Q.74 Which cytokine is commonly elevated in rheumatoid arthritis patients?
IL‑6
IL‑2
IL‑4
IL‑10
Explanation - IL‑6 is a key pro‑inflammatory cytokine elevated in rheumatoid arthritis, contributing to joint inflammation.
Correct answer is: IL‑6
Q.75 What does the term 'biosensor sensitivity' refer to in the context of cytokine detection?
The lowest detectable concentration of the cytokine
The speed of detection
The sensor’s ability to reject noise
The stability over time
Explanation - Sensitivity is defined by the minimum detectable analyte concentration, often expressed as the limit of detection.
Correct answer is: The lowest detectable concentration of the cytokine
Q.76 Which cytokine is secreted by Th1 cells and is known to have antiviral properties?
IFN‑γ
IL‑4
IL‑12
IL‑10
Explanation - IFN‑γ activates macrophages and enhances antiviral immunity.
Correct answer is: IFN‑γ
Q.77 Which of the following is a common strategy to reduce non‑specific binding in cytokine immunosensors?
Use of blocking agents like BSA
Increased temperature during incubation
High salt concentration
Longer incubation times
Explanation - Blocking agents cover nonspecific binding sites, reducing background noise.
Correct answer is: Use of blocking agents like BSA
Q.78 Which cytokine is a key mediator of inflammation in sepsis and is a target for therapeutic antibodies?
TNF‑α
IL‑2
IL‑4
IL‑10
Explanation - TNF‑α drives systemic inflammation in sepsis; anti‑TNF‑α therapies are used clinically.
Correct answer is: TNF‑α
Q.79 What is the main advantage of using an interdigitated microelectrode array (IDMA) for cytokine detection?
High optical resolution
Large surface area for antibody immobilization
Low electrical resistance
Ability to measure temperature changes
Explanation - IDMAs provide many electrode fingers, increasing the area for capturing analytes.
Correct answer is: Large surface area for antibody immobilization
Q.80 Which cytokine is known to stimulate the production of reactive oxygen species (ROS) in neutrophils?
IL‑8
IL‑2
TNF‑α
IFN‑γ
Explanation - TNF‑α activates neutrophils, leading to ROS generation as part of the respiratory burst.
Correct answer is: TNF‑α
Q.81 What is the role of IL‑33 in the immune system?
Activates Th2 cells and innate lymphoid cells
Suppresses B cell activation
Promotes apoptosis of NK cells
Inhibits mast cell degranulation
Explanation - IL‑33 is an alarmin that stimulates Th2 responses and innate lymphoid cell activation.
Correct answer is: Activates Th2 cells and innate lymphoid cells
Q.82 Which cytokine is crucial for the maintenance of mucosal barrier integrity?
IL‑22
IL‑4
IL‑2
IL‑10
Explanation - IL‑22 supports epithelial cell proliferation and barrier function in mucosal tissues.
Correct answer is: IL‑22
Q.83 What is the typical effect of IL‑1β on endothelial cells?
Increases adhesion molecule expression
Decreases cytokine production
Stimulates cell division
Induces apoptosis
Explanation - IL‑1β upregulates ICAM‑1 and VCAM‑1 on endothelial cells, promoting leukocyte adhesion.
Correct answer is: Increases adhesion molecule expression
Q.84 Which of the following best describes the role of IL‑12 in Th1 differentiation?
It blocks STAT3 activation
It activates STAT4 signaling
It promotes STAT6 phosphorylation
It inhibits IL‑2 production
Explanation - IL‑12 signals via STAT4 to drive Th1 differentiation.
Correct answer is: It activates STAT4 signaling
Q.85 Which sensor technology uses the change in surface plasmon resonance to detect cytokine binding?
Quartz crystal microbalance (QCM)
Surface plasmon resonance (SPR)
Electrochemical impedance spectroscopy (EIS)
Mass spectrometry
Explanation - SPR measures changes in refractive index near the sensor surface upon cytokine binding.
Correct answer is: Surface plasmon resonance (SPR)
Q.86 What is the primary function of IL‑12 in antiviral immunity?
Promotes B cell antibody production
Enhances cytotoxic T cell activity
Induces antibody class switching to IgE
Suppresses NK cell activation
Explanation - IL‑12 activates cytotoxic T cells and NK cells, improving antiviral responses.
Correct answer is: Enhances cytotoxic T cell activity
Q.87 Which cytokine is primarily responsible for the differentiation of Th2 cells?
IL‑2
IL‑4
IL‑12
IL‑17
Explanation - IL‑4 drives the differentiation of naïve T cells into Th2 cells.
Correct answer is: IL‑4
Q.88 Which of the following is NOT a typical feature of a cytokine‑based immunosensor?
Label‑free detection
Real‑time monitoring
Need for fluorescent tags
High specificity for the target cytokine
Explanation - Many immunosensors are label‑free, using electrical or optical signals without fluorescence.
Correct answer is: Need for fluorescent tags
Q.89 What is the main advantage of using a microfluidic platform for cytokine detection?
High sample volume requirement
Rapid mixing and low reagent consumption
Large electrode area
High mechanical rigidity
Explanation - Microfluidics enable precise control of small volumes and fast reaction times.
Correct answer is: Rapid mixing and low reagent consumption
Q.90 Which cytokine is a key driver of Th17 cell differentiation?
IL‑6
IL‑4
IL‑12
IFN‑γ
Explanation - IL‑6, together with TGF‑β, promotes Th17 differentiation.
Correct answer is: IL‑6
Q.91 Which of the following statements about IL‑1 is correct?
IL‑1 is a type of chemokine
IL‑1 is a pro‑inflammatory cytokine
IL‑1 is produced exclusively by neutrophils
IL‑1 is anti‑inflammatory
Explanation - IL‑1α and IL‑1β are key pro‑inflammatory mediators.
Correct answer is: IL‑1 is a pro‑inflammatory cytokine
Q.92 What is the key advantage of a flexible electrochemical sensor for in‑vivo cytokine monitoring?
High rigidity for stable contact
Conformability to tissue surfaces
Reduced manufacturing cost
Improved optical clarity
Explanation - Flexible sensors can wrap around tissues, enabling continuous, real‑time monitoring.
Correct answer is: Conformability to tissue surfaces
Q.93 Which cytokine is primarily involved in the recruitment of eosinophils during allergic responses?
IL‑5
IL‑2
TNF‑α
IL‑10
Explanation - IL‑5 stimulates eosinophil growth and activation.
Correct answer is: IL‑5
Q.94 Which cytokine is a hallmark of Th17 cell function?
IL‑17
IL‑4
IL‑12
IFN‑γ
Explanation - IL‑17 is the signature cytokine of Th17 cells, driving inflammation.
Correct answer is: IL‑17
Q.95 Which of the following is a primary effect of IL‑6 in the acute‑phase response?
Induces IL‑10 secretion
Stimulates C‑reactive protein production
Suppresses B cell activation
Reduces fever
Explanation - IL‑6 signals the liver to produce acute‑phase proteins like CRP.
Correct answer is: Stimulates C‑reactive protein production
Q.96 What does the 'binding constant' (K_d) of a cytokine‑antibody pair indicate?
The rate of antibody production
The equilibrium affinity between cytokine and antibody
The maximum detection limit of a sensor
The speed of signal transduction
Explanation - K_d quantifies how tightly an antibody binds its antigen; lower K_d means higher affinity.
Correct answer is: The equilibrium affinity between cytokine and antibody
Q.97 Which cytokine is involved in the activation of B cells to produce IgA antibodies?
IL‑21
IL‑10
IL‑4
IL‑12
Explanation - IL‑21 drives class switching to IgA in mucosal immune responses.
Correct answer is: IL‑21
Q.98 Which of the following cytokines is best known for its role in granulocyte‑macrophage colony‑stimulating factor (GM‑CSF) induction?
IL‑3
IL‑6
IL‑5
IL‑10
Explanation - IL‑3 promotes the growth of granulocytes and macrophages, influencing GM‑CSF production.
Correct answer is: IL‑3
Q.99 Which technique would provide the fastest real‑time monitoring of cytokine secretion from single cells?
ELISA
Microcantilever sensor
Flow cytometry
Western blot
Explanation - Microcantilever sensors can detect mechanical changes due to cytokine binding in real‑time at single‑cell levels.
Correct answer is: Microcantilever sensor
Q.100 Which cytokine is most commonly elevated in patients with inflammatory bowel disease (IBD)?
IL‑6
IL‑4
IL‑2
IL‑10
Explanation - IL‑6 is often up‑regulated in IBD, contributing to chronic inflammation.
Correct answer is: IL‑6
Q.101 What is the role of IL‑8 in inflammation?
Stimulates antibody production
Attracts neutrophils to the site of infection
Promotes T cell apoptosis
Suppresses cytokine release
Explanation - IL‑8 is a chemokine that chemotacts neutrophils during inflammatory responses.
Correct answer is: Attracts neutrophils to the site of infection
Q.102 Which cytokine is a key regulator of Th1/Th2 balance in allergic diseases?
IL‑10
IL‑12
IL‑4
IL‑6
Explanation - IL‑12 promotes Th1 differentiation, counteracting Th2‑driven allergies.
Correct answer is: IL‑12
Q.103 In an impedance‑based immunosensor, what does a sharp decrease in phase angle typically indicate?
Increased charge transfer resistance
Improved electron transfer efficiency
Higher background noise
Reduced dielectric constant
Explanation - A lower phase angle often reflects better charge transfer across the electrode interface after antibody‑antigen binding.
Correct answer is: Improved electron transfer efficiency
Q.104 Which cytokine is primarily secreted by mast cells during allergic reactions?
IL‑6
IL‑5
IL‑13
IL‑2
Explanation - IL‑13 contributes to IgE production and smooth muscle contraction in allergies.
Correct answer is: IL‑13
Q.105 Which of the following is a key function of IL‑10 in the gut?
Promotes inflammation
Suppresses mucosal immune responses
Stimulates mucus secretion
Induces apoptosis of epithelial cells
Explanation - IL‑10 dampens inflammation to protect the gut lining from damage.
Correct answer is: Suppresses mucosal immune responses
Q.106 Which of these cytokines is NOT typically produced by Th2 cells?
IL‑5
IL‑13
IL‑17
IL‑4
Explanation - IL‑17 is a Th17 cytokine, not produced by Th2 cells.
Correct answer is: IL‑17
Q.107 What is the main purpose of using a reference electrode in an electrochemical cytokine sensor?
To provide a constant potential reference
To measure temperature changes
To supply the signal current
To act as a biospecific binding site
Explanation - A reference electrode establishes a stable potential for accurate voltage measurements.
Correct answer is: To provide a constant potential reference
Q.108 Which cytokine is known to enhance the expression of MHC class II molecules on antigen‑presenting cells?
IFN‑γ
IL‑4
IL‑6
IL‑10
Explanation - IFN‑γ upregulates MHC‑II expression, enhancing antigen presentation to CD4⁺ T cells.
Correct answer is: IFN‑γ
Q.109 Which of the following is a common method to quantify cytokine concentration in a sample?
Western blot
Enzyme‑linked immunosorbent assay (ELISA)
PCR
Mass spectrometry of DNA
Explanation - ELISA is a standard, sensitive method for measuring cytokine levels.
Correct answer is: Enzyme‑linked immunosorbent assay (ELISA)
Q.110 In a label‑free optical biosensor, which physical property changes upon cytokine binding?
Refractive index near the sensor surface
Temperature of the solution
Molecular weight of the antibody
Electrical resistance of the sensor
Explanation - Binding alters the local refractive index, which is detected by optical sensors.
Correct answer is: Refractive index near the sensor surface
Q.111 Which cytokine is a primary regulator of inflammatory responses in asthma?
IL‑13
IL‑2
TNF‑α
IL‑10
Explanation - IL‑13 drives airway hyperresponsiveness and mucus production in asthma.
Correct answer is: IL‑13
Q.112 What is the main advantage of a microelectrode array with interdigitated design for cytokine detection?
Simplified fabrication
Increased signal‑to‑noise ratio due to larger electrode spacing
Higher effective surface area for immobilization
Reduced need for reference electrodes
Explanation - The interdigitated structure provides many electrode surfaces for antibody attachment, improving sensitivity.
Correct answer is: Higher effective surface area for immobilization
Q.113 Which cytokine is a marker for systemic inflammation and is often measured in sepsis diagnostics?
IL‑6
IL‑2
IL‑4
IL‑10
Explanation - IL‑6 is a key inflammatory cytokine elevated in sepsis and used as a diagnostic marker.
Correct answer is: IL‑6
Q.114 Which cytokine promotes the differentiation of Th9 cells?
IL‑9
IL‑21
IL‑12
IL‑23
Explanation - IL‑9 is involved in Th9 differentiation, contributing to allergic inflammation.
Correct answer is: IL‑9
Q.115 Which of the following is NOT a function of IL‑10?
Suppresses Th1 responses
Reduces production of pro‑inflammatory cytokines
Promotes B‑cell activation and antibody secretion
Acts as an anti‑inflammatory mediator
Explanation - IL‑10 primarily suppresses immune responses rather than activating B cells for antibody production.
Correct answer is: Promotes B‑cell activation and antibody secretion
Q.116 Which cytokine is critical for the activation of macrophages during an innate immune response?
TNF‑α
IL‑2
IL‑4
IL‑10
Explanation - TNF‑α activates macrophages, enhancing phagocytosis and cytokine secretion.
Correct answer is: TNF‑α
Q.117 What does the term 'biosensor specificity' refer to?
The sensor’s ability to detect only the target cytokine
The speed of the detection process
The sensor’s mechanical durability
The cost of the sensor
Explanation - Specificity indicates how well the sensor discriminates the target from other molecules.
Correct answer is: The sensor’s ability to detect only the target cytokine
Q.118 Which cytokine is a major mediator of inflammation in type‑2 diabetes?
IL‑6
IL‑2
IL‑4
IL‑10
Explanation - IL‑6 contributes to insulin resistance and chronic low‑grade inflammation in type‑2 diabetes.
Correct answer is: IL‑6
Q.119 Which of the following best describes the role of IL‑23?
Promotes Th1 differentiation
Maintains Th17 cells and supports their function
Induces B‑cell apoptosis
Suppresses NK cell activity
Explanation - IL‑23 stabilizes Th17 cells and enhances their inflammatory cytokine production.
Correct answer is: Maintains Th17 cells and supports their function
Q.120 In impedance‑based cytokine sensors, what is the effect of adding a blocking agent like BSA to the electrode surface?
Increases non‑specific binding
Reduces background signal and improves specificity
Decreases sensitivity to the target cytokine
Changes the electrode’s electrical resistance drastically
Explanation - Blocking agents occupy nonspecific sites, lowering background noise.
Correct answer is: Reduces background signal and improves specificity
Q.121 Which cytokine is known to stimulate the production of IgG antibodies in B cells?
IL‑21
IL‑4
IL‑6
IL‑10
Explanation - IL‑21 enhances B‑cell differentiation and IgG class switching.
Correct answer is: IL‑21
Q.122 Which of the following is a key function of IL‑1β in the immune response?
Suppresses cytokine secretion
Promotes the maturation of dendritic cells
Induces the expression of adhesion molecules on endothelial cells
Inhibits T‑cell activation
Explanation - IL‑1β upregulates ICAM‑1 and VCAM‑1, facilitating leukocyte adhesion.
Correct answer is: Induces the expression of adhesion molecules on endothelial cells
Q.123 What is the main advantage of a nanoplasmonic biosensor for cytokine detection?
High mechanical strength
Low cost fabrication
Enhanced sensitivity due to localized surface plasmon resonance
Inability to detect low concentrations
Explanation - Nanoplasmonic structures amplify optical signals, enabling ultra‑sensitive cytokine detection.
Correct answer is: Enhanced sensitivity due to localized surface plasmon resonance
Q.124 Which cytokine is known to be a key driver of the Th2 immune response?
IL‑4
IL‑12
IL‑17
IL‑2
Explanation - IL‑4 is the hallmark cytokine that directs Th2 differentiation.
Correct answer is: IL‑4
Q.125 In a microfluidic immunosensor, what is the purpose of a serpentine channel design?
To increase mixing efficiency
To reduce fluid velocity
To provide optical access
To increase electrode surface area
Explanation - Serpentine channels create turbulence, improving contact between analyte and sensor surface.
Correct answer is: To increase mixing efficiency
Q.126 Which cytokine is primarily responsible for stimulating T cell proliferation?
IL‑2
IL‑4
IL‑6
TNF‑α
Explanation - IL‑2 is a growth factor for T cells, promoting their expansion.
Correct answer is: IL‑2
Q.127 Which of the following cytokines is a major driver of chronic inflammation in rheumatoid arthritis?
IL‑6
IL‑2
IL‑4
IL‑10
Explanation - IL‑6 is heavily involved in joint inflammation and systemic symptoms in RA.
Correct answer is: IL‑6
Q.128 What is the main advantage of using a flexible printed circuit board (PCB) for cytokine sensors?
Increased stiffness
Better conformability to biological surfaces
Higher cost
Lower signal quality
Explanation - Flexible PCBs can wrap around tissues for improved contact and signal fidelity.
Correct answer is: Better conformability to biological surfaces
Q.129 Which cytokine is a hallmark of Th17 cell activation?
IL‑17
IL‑4
IL‑12
IL‑10
Explanation - IL‑17 is produced by Th17 cells and drives pro‑inflammatory responses.
Correct answer is: IL‑17
Q.130 Which cytokine is most often targeted by biologic therapies in inflammatory bowel disease?
TNF‑α
IL‑2
IL‑4
IL‑6
Explanation - Anti‑TNF‑α biologics are widely used to reduce inflammation in IBD.
Correct answer is: TNF‑α
Q.131 What does the term 'biosensor limit of detection' (LOD) represent?
The maximum amount the sensor can measure
The minimum amount that can be distinguished from noise
The time required to measure the analyte
The number of times the sensor can be reused
Explanation - LOD indicates the lowest detectable concentration of the target cytokine.
Correct answer is: The minimum amount that can be distinguished from noise
Q.132 Which cytokine is a key driver of the Th1 immune response?
IL‑12
IL‑4
IL‑17
IL‑2
Explanation - IL‑12 activates Th1 differentiation via STAT4 signaling.
Correct answer is: IL‑12
Q.133 What is the effect of IL‑5 on eosinophils?
Promotes their apoptosis
Inhibits their maturation
Stimulates their proliferation and activation
Has no effect on eosinophils
Explanation - IL‑5 promotes growth and activation of eosinophils, key in allergic responses.
Correct answer is: Stimulates their proliferation and activation
Q.134 Which cytokine is produced by Th1 cells and enhances the activity of macrophages?
IFN‑γ
IL‑4
IL‑12
IL‑2
Explanation - IFN‑γ is a hallmark Th1 cytokine that activates macrophages.
Correct answer is: IFN‑γ
Q.135 Which of the following is a typical feature of a label‑free optical cytokine biosensor?
Requires fluorescent tags
Measures changes in refractive index
Uses radioactive labeling
Detects mass changes only
Explanation - Label‑free optical sensors detect changes in refractive index upon cytokine binding.
Correct answer is: Measures changes in refractive index
Q.136 Which cytokine is crucial for the activation of natural killer (NK) cells?
IL‑15
IL‑4
IL‑2
IL‑12
Explanation - IL‑15 stimulates NK cell proliferation and activity.
Correct answer is: IL‑15
Q.137 Which of the following is NOT a common method to measure cytokine levels in a sample?
ELISA
Mass spectrometry
PCR
Surface plasmon resonance (SPR)
Explanation - PCR detects nucleic acids, not proteins like cytokines.
Correct answer is: PCR
Q.138 What is the main advantage of using a graphene‑based sensor for cytokine detection?
Low sensitivity
High surface area and excellent electrical conductivity
High optical absorption
Large bandgap for better selectivity
Explanation - Graphene’s properties enhance signal transduction and sensitivity.
Correct answer is: High surface area and excellent electrical conductivity
Q.139 Which cytokine is predominantly produced by Th2 cells and promotes B‑cell differentiation?
IL‑4
IL‑2
IL‑6
IL‑12
Explanation - IL‑4 drives B‑cell differentiation and IgE class switching.
Correct answer is: IL‑4
Q.140 In impedance spectroscopy, which parameter is directly related to the double‑layer capacitance at the electrode interface?
Real part of impedance (Z')
Imaginary part of impedance (Z'')
Phase angle
Both Z' and Z''
Explanation - The imaginary part is associated with capacitive behavior of the electrode interface.
Correct answer is: Imaginary part of impedance (Z'')
Q.141 Which cytokine is a major mediator of inflammation in type 1 diabetes?
IL‑1β
IL‑2
IL‑4
IL‑10
Explanation - IL‑1β contributes to beta‑cell destruction and chronic inflammation in type 1 diabetes.
Correct answer is: IL‑1β
Q.142 Which cytokine is involved in the regulation of the gut mucosal barrier and is often elevated in inflammatory bowel disease?
IL‑6
IL‑4
IL‑2
IL‑10
Explanation - IL‑10 helps maintain gut mucosal tolerance and is often dysregulated in IBD.
Correct answer is: IL‑10
Q.143 What is the primary role of IL‑12 in the immune system?
Induces B‑cell apoptosis
Promotes Th1 differentiation
Stimulates Th2 differentiation
Suppresses NK cell activity
Explanation - IL‑12 activates Th1 cells, enhancing cell‑mediated immunity.
Correct answer is: Promotes Th1 differentiation
Q.144 Which cytokine is primarily secreted by mast cells and is a key driver of allergic inflammation?
IL‑13
IL‑6
IL‑5
IL‑2
Explanation - IL‑13 promotes IgE production and smooth muscle contraction in allergies.
Correct answer is: IL‑13
Q.145 Which of the following cytokines is a hallmark of the Th1 response?
IFN‑γ
IL‑4
IL‑17
IL‑5
Explanation - IFN‑γ is a signature cytokine of Th1 cells.
Correct answer is: IFN‑γ
Q.146 What is the main benefit of a flexible electrochemical sensor in biosensing applications?
High mechanical rigidity
Conformability to curved surfaces
Reduced signal quality
Increased cost
Explanation - Flexibility allows the sensor to maintain close contact with irregular biological surfaces.
Correct answer is: Conformability to curved surfaces
Q.147 Which cytokine is involved in the regulation of Th17 cell maintenance and function?
IL‑23
IL‑4
IL‑2
IL‑12
Explanation - IL‑23 stabilizes and promotes Th17 activity.
Correct answer is: IL‑23
Q.148 What is the effect of IL‑2 on T cells?
Inhibits proliferation
Promotes growth and proliferation
Induces apoptosis
Suppresses cytokine production
Explanation - IL‑2 is a key growth factor for T cells.
Correct answer is: Promotes growth and proliferation
Q.149 Which of the following is a key feature of a label‑free electrochemical immunosensor?
Requires fluorescent labeling
Measures changes in impedance or current directly
Uses radioactive tracers
Detects mass changes only
Explanation - Label‑free sensors detect binding events through electrical changes without labels.
Correct answer is: Measures changes in impedance or current directly
Q.150 Which cytokine is commonly associated with allergic inflammation and is a target for anti‑IL‑5 therapy?
IL‑5
IL‑4
IL‑6
IL‑2
Explanation - Anti‑IL‑5 antibodies are used to treat eosinophilic asthma and other allergic disorders.
Correct answer is: IL‑5
Q.151 What is the role of IL‑6 in the immune system?
Promotes B‑cell differentiation and acute‑phase response
Suppresses antibody production
Stimulates apoptosis of immune cells
Inhibits cytokine production
Explanation - IL‑6 drives B‑cell maturation and signals the liver for acute‑phase protein production.
Correct answer is: Promotes B‑cell differentiation and acute‑phase response
Q.152 Which of the following cytokines is primarily involved in the promotion of IgE class switching?
IL‑4
IL‑2
IL‑6
IL‑10
Explanation - IL‑4 induces IgE class switching in B cells, crucial for allergic responses.
Correct answer is: IL‑4
Q.153 Which cytokine is a key regulator of Th9 differentiation?
IL‑9
IL‑21
IL‑12
IL‑23
Explanation - IL‑9 is involved in Th9 cell development and allergic inflammation.
Correct answer is: IL‑9
Q.154 What is the function of IL‑10 in the immune response?
Promotes inflammation
Suppresses pro‑inflammatory cytokine production
Activates NK cells
Stimulates antibody secretion
Explanation - IL‑10 is an anti‑inflammatory cytokine that limits immune activation.
Correct answer is: Suppresses pro‑inflammatory cytokine production