Applications of biosensors MCQs With Answer

Applications of biosensors MCQs With Answer

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Applications of biosensors MCQs With Answer

Introduction: Biosensors integrate a biologically sensitive element with a physicochemical transducer to convert a biological interaction into a measurable signal. For M.Pharm students, understanding biosensor applications is essential for drug analysis, therapeutic drug monitoring, pharmacokinetics, point-of-care diagnostics, and quality control in pharmaceutical manufacturing. This quiz collection focuses on practical and advanced aspects—transduction principles, receptor types (enzymes, antibodies, aptamers, MIPs), immobilization strategies, signal amplification, nanomaterial enhancements, and regulatory validation criteria—preparing students to evaluate, design, and critically use biosensors in pharmaceutical biotechnology and clinical settings.

Q1. Which set lists the primary functional components of a biosensor?

  • Bioreceptor, transducer, signal processor, and reference electrode
  • Bioreceptor, transducer, signal processor, and sample handling
  • Transducer, data logger, battery, and display
  • Enzyme, antibody, aptamer, and polymer

Correct Answer: Bioreceptor, transducer, signal processor, and sample handling

Q2. Which transduction method is most commonly employed in enzyme-based biosensors for quantifying small molecule analytes?

  • Optical fluorescence detection
  • Thermal calorimetry
  • Electrochemical (amperometric) detection
  • Piezoelectric frequency shift

Correct Answer: Electrochemical (amperometric) detection

Q3. An amperometric biosensor primarily measures which physical quantity that is proportional to analyte concentration?

  • Voltage difference between electrodes
  • Electric current produced by a redox reaction
  • Change in solution resistance
  • Mass deposition on the sensor surface

Correct Answer: Electric current produced by a redox reaction

Q4. Surface plasmon resonance (SPR) biosensors detect binding events by monitoring which phenomenon?

  • Change in mass producing a frequency shift
  • Change in refractive index at a metal-dielectric interface
  • Emission of photons from labeled antibodies
  • Variation in solution conductivity

Correct Answer: Change in refractive index at a metal-dielectric interface

Q5. Aptamers used in biosensors are best described as:

  • Short peptides selected by phage display
  • Single-stranded DNA or RNA molecules selected by SELEX with high affinity
  • Polysaccharide coatings that capture proteins
  • Antibody fragments produced by hybridoma cells

Correct Answer: Single-stranded DNA or RNA molecules selected by SELEX with high affinity

Q6. Which immobilization strategy typically provides the greatest long-term stability for protein bioreceptors on electrode surfaces?

  • Physical adsorption via van der Waals forces
  • Covalent bonding through functional group coupling
  • Entrapment in a freely diffusing polymer solution
  • Simple physisorption on hydrophobic surfaces

Correct Answer: Covalent bonding through functional group coupling

Q7. Limit of detection (LOD) of a biosensor is most directly limited by which factor?

  • Color of the sensing substrate
  • Signal-to-noise ratio and background noise level
  • Size of the sample container
  • Manufacturer brand

Correct Answer: Signal-to-noise ratio and background noise level

Q8. Which of the following is a label-free biosensing technique commonly used for kinetic analysis?

  • Enzyme-linked immunosorbent assay (ELISA)
  • Fluorescence resonance energy transfer (FRET)
  • Surface plasmon resonance (SPR)
  • Radioimmunoassay (RIA)

Correct Answer: Surface plasmon resonance (SPR)

Q9. Molecularly imprinted polymers (MIPs) act as recognition elements in biosensors by:

  • Using living cells to metabolize analytes
  • Providing template-shaped cavities complementary to target molecules
  • Generating electrical signals via enzymatic turnover
  • Emitting light upon analyte binding

Correct Answer: Providing template-shaped cavities complementary to target molecules

Q10. Incorporation of nanomaterials (e.g., gold nanoparticles, graphene, carbon nanotubes) into biosensor electrodes primarily improves which characteristics?

  • Mechanical rigidity and weight
  • Surface area, electron transfer kinetics, and sensitivity
  • Ability to operate at extreme temperatures only
  • Fluorescence lifetimes of labels

Correct Answer: Surface area, electron transfer kinetics, and sensitivity

Q11. Electrochemical impedance spectroscopy (EIS)-based biosensors detect analyte binding by measuring changes in:

  • Optical absorbance at a specific wavelength
  • Interfacial impedance and charge transfer resistance
  • Thermal power generated during binding
  • Magnetic resonance frequency

Correct Answer: Interfacial impedance and charge transfer resistance

Q12. FRET-based biosensors provide proximity-dependent signals. Which is essential for FRET to occur?

  • Donor and acceptor fluorophores separated by >20 nm
  • Donor-acceptor spectral overlap and close proximity (typically <10 nm)
  • Presence of an electrochemical mediator
  • Vacuum conditions to prevent quenching

Correct Answer: Donor-acceptor spectral overlap and close proximity (typically <10 nm)

Q13. Which parameter defines the concentration interval where biosensor response is proportional to analyte concentration?

  • Limit of detection
  • Linear dynamic range
  • Selectivity coefficient
  • Turnover number (kcat)

Correct Answer: Linear dynamic range

Q14. Which enzyme is most widely used in first-generation electrochemical glucose biosensors?

  • Glucose dehydrogenase (GDH) with NAD+
  • Glucose oxidase (GOx)
  • Hexokinase
  • Sucrose phosphorylase

Correct Answer: Glucose oxidase (GOx)

Q15. For reusable affinity biosensors, an effective regeneration strategy should ideally:

  • Use high concentrations of strong acids to destroy bound analyte
  • Employ mild conditions that dissociate analyte without damaging the bioreceptor
  • Permanently denature the receptor after each cycle
  • Rely exclusively on mechanical scraping of the surface

Correct Answer: Employ mild conditions that dissociate analyte without damaging the bioreceptor

Q16. Which design attributes are most critical for point-of-care (POC) biosensors in clinical settings?

  • High cost, laboratory-only operation, and long assay time
  • Portability, rapid response, and user-friendly operation
  • Large sample volumes and complex instrumentation
  • Single-use only with no result display

Correct Answer: Portability, rapid response, and user-friendly operation

Q17. Label-free biosensors offer advantages for kinetic analysis because they:

  • Require fluorescent labels that slow binding kinetics
  • Distort binding equilibrium due to large tags
  • Measure binding in real time without labels, preserving native interactions
  • Only provide end-point measurements

Correct Answer: Measure binding in real time without labels, preserving native interactions

Q18. Quartz crystal microbalance (QCM) biosensors detect analyte binding by monitoring changes in:

  • Optical absorbance
  • Resonant frequency due to mass loading on the crystal
  • Solution pH
  • Electrochemical current

Correct Answer: Resonant frequency due to mass loading on the crystal

Q19. Which molecular amplification strategy is especially useful to amplify nucleic acid signals in biosensors without thermal cycling?

  • Polymerase chain reaction (PCR) with thermal cycling
  • Rolling circle amplification (RCA)
  • Western blotting
  • Size-exclusion chromatography

Correct Answer: Rolling circle amplification (RCA)

Q20. Regulatory validation of biosensors for pharmaceutical or clinical use typically requires demonstration of which analytical performance characteristics?

  • Only color and shape of the device
  • Accuracy, precision, specificity, limit of detection, and linearity
  • Only user interface aesthetics
  • Packaging weight and manufacturer logo clarity

Correct Answer: Accuracy, precision, specificity, limit of detection, and linearity

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