Podcast
Questions and Answers
A transducer is a device that converts variations in a physical quantity into an ______ signal.
A transducer is a device that converts variations in a physical quantity into an ______ signal.
electrical
In a biosensor, the transducer converts biochemical interactions into measurable ______ signals.
In a biosensor, the transducer converts biochemical interactions into measurable ______ signals.
electric
Sensors are devices that convert a physical parameter to an electrical ______.
Sensors are devices that convert a physical parameter to an electrical ______.
output
Actuators are devices that convert an electrical signal to a physical ______.
Actuators are devices that convert an electrical signal to a physical ______.
Signup and view all the answers
Amperometric transduction measures the current that flows, which is directly proportional to the analyte ______.
Amperometric transduction measures the current that flows, which is directly proportional to the analyte ______.
Signup and view all the answers
To increase the selectivity of the detecting electrode in amperometric transduction, ______ are commonly used.
To increase the selectivity of the detecting electrode in amperometric transduction, ______ are commonly used.
Signup and view all the answers
One type of biosensor based on electrochemical reactions is the ______ biosensor.
One type of biosensor based on electrochemical reactions is the ______ biosensor.
Signup and view all the answers
Cellulose acetate and Nafion are examples of ______ used in biosensors.
Cellulose acetate and Nafion are examples of ______ used in biosensors.
Signup and view all the answers
Ion-selective electrodes are used to determine changes in concentration of chosen ______, e.g., hydrogen ions.
Ion-selective electrodes are used to determine changes in concentration of chosen ______, e.g., hydrogen ions.
Signup and view all the answers
Polymeric membrane electrodes are commercially available for the selective detection of several ______ such as K+, Na+, and Ca2+.
Polymeric membrane electrodes are commercially available for the selective detection of several ______ such as K+, Na+, and Ca2+.
Signup and view all the answers
Ion Selective Field Effect Transistors (ISFETs) are miniature ______ made using CMOS technology.
Ion Selective Field Effect Transistors (ISFETs) are miniature ______ made using CMOS technology.
Signup and view all the answers
ISE-based biosensors are mainly used for ______ and creatinine measurement.
ISE-based biosensors are mainly used for ______ and creatinine measurement.
Signup and view all the answers
Elevated creatinine level signifies impaired kidney ______ or kidney disease.
Elevated creatinine level signifies impaired kidney ______ or kidney disease.
Signup and view all the answers
Amplified potentiometric transduction of DNA hybridization involves liposome 'nanocarriers' loaded with signaling ______.
Amplified potentiometric transduction of DNA hybridization involves liposome 'nanocarriers' loaded with signaling ______.
Signup and view all the answers
Conductivity is a measurement of the ability of a solution to conduct an electric ______.
Conductivity is a measurement of the ability of a solution to conduct an electric ______.
Signup and view all the answers
Instruments measure conductivity by placing two plates of conductive material with known area and distance apart in a ______.
Instruments measure conductivity by placing two plates of conductive material with known area and distance apart in a ______.
Signup and view all the answers
Mediators are artificial electron acceptor molecules that serve as an e- transfer shuttle to facilitate __________ transfer from the active site of the enzyme to the electrode.
Mediators are artificial electron acceptor molecules that serve as an e- transfer shuttle to facilitate __________ transfer from the active site of the enzyme to the electrode.
Signup and view all the answers
To achieve lower applied potential for the oxidation of enzymatically generated H2O2, electrodes are metallised using noble metals like __________ and palladium.
To achieve lower applied potential for the oxidation of enzymatically generated H2O2, electrodes are metallised using noble metals like __________ and palladium.
Signup and view all the answers
Polymers such as __________ can be employed to prevent interfering species from reaching the electrode surface.
Polymers such as __________ can be employed to prevent interfering species from reaching the electrode surface.
Signup and view all the answers
The wearable tattoo-based alcohol biosensing system induces sweat through the transdermal delivery of the drug __________ using iontophoresis.
The wearable tattoo-based alcohol biosensing system induces sweat through the transdermal delivery of the drug __________ using iontophoresis.
Signup and view all the answers
Amperometric detection of __________ in generated sweat utilizes the alcohol-oxidase enzyme.
Amperometric detection of __________ in generated sweat utilizes the alcohol-oxidase enzyme.
Signup and view all the answers
A potentiometric biosensor measures the potential under __________ current conditions.
A potentiometric biosensor measures the potential under __________ current conditions.
Signup and view all the answers
The potential generated in a potentiometric biosensor is directly proportional to the logarithm of the __________ concentration.
The potential generated in a potentiometric biosensor is directly proportional to the logarithm of the __________ concentration.
Signup and view all the answers
The setup includes a scheme of the wireless operation for transdermal alcohol __________.
The setup includes a scheme of the wireless operation for transdermal alcohol __________.
Signup and view all the answers
A voltage potential is applied and the resulting current is measured in a technique that assesses changes in ionic ______.
A voltage potential is applied and the resulting current is measured in a technique that assesses changes in ionic ______.
Signup and view all the answers
The developed biosensor is based on the inhibition of the activity of alkaline ______, which is immobilized on the glass internal surface.
The developed biosensor is based on the inhibition of the activity of alkaline ______, which is immobilized on the glass internal surface.
Signup and view all the answers
Optical sensors rely on optical ______ of the signal and comprise spectrophotometry in different light ranges.
Optical sensors rely on optical ______ of the signal and comprise spectrophotometry in different light ranges.
Signup and view all the answers
In colorimetric detection of a western blot, the signal generated is a ______ precipitate.
In colorimetric detection of a western blot, the signal generated is a ______ precipitate.
Signup and view all the answers
Chemiluminescence detection emits ______ as a signal during the detection process.
Chemiluminescence detection emits ______ as a signal during the detection process.
Signup and view all the answers
Photonic crystals are periodic optical nanostructures that can selectively couple energy at particular ______.
Photonic crystals are periodic optical nanostructures that can selectively couple energy at particular ______.
Signup and view all the answers
Miniaturization in optical transducers allows for ______ measurements to be conducted.
Miniaturization in optical transducers allows for ______ measurements to be conducted.
Signup and view all the answers
A disadvantage of optical transducers is that ambient light is a strong ______.
A disadvantage of optical transducers is that ambient light is a strong ______.
Signup and view all the answers
PC biosensors have been applied to the detection of antibody–antigen and small molecule–protein interactions, as well as ______-based assays.
PC biosensors have been applied to the detection of antibody–antigen and small molecule–protein interactions, as well as ______-based assays.
Signup and view all the answers
The PCs utilized in the biomolecular interaction detection system are composed of an epoxy-cured polycarbonate ______ that is coated with a thin layer of TiO2.
The PCs utilized in the biomolecular interaction detection system are composed of an epoxy-cured polycarbonate ______ that is coated with a thin layer of TiO2.
Signup and view all the answers
Binding of macromolecules is monitored by shifts of nanometres in wavelength with a sensitivity of less than ______ pg/mm2.
Binding of macromolecules is monitored by shifts of nanometres in wavelength with a sensitivity of less than ______ pg/mm2.
Signup and view all the answers
Crystalline colloidal arrays (CCA) self-assembled because of electrostatic ______ between particles.
Crystalline colloidal arrays (CCA) self-assembled because of electrostatic ______ between particles.
Signup and view all the answers
The hydrogel is functionalized with a molecular recognition agent, which interacts with the analyte to actuate either shrinking or ______.
The hydrogel is functionalized with a molecular recognition agent, which interacts with the analyte to actuate either shrinking or ______.
Signup and view all the answers
Surface Plasmon Resonance (SPR) is an optical phenomenon due to a charge density oscillation at the interface of a ______ and a dielectric.
Surface Plasmon Resonance (SPR) is an optical phenomenon due to a charge density oscillation at the interface of a ______ and a dielectric.
Signup and view all the answers
In the Kretschmann configuration, prisms are coated with a thin film of metal, usually gold or ______.
In the Kretschmann configuration, prisms are coated with a thin film of metal, usually gold or ______.
Signup and view all the answers
Above a certain incidence angle, all of the light is ______.
Above a certain incidence angle, all of the light is ______.
Signup and view all the answers
The phenomenon known as ______ Internal Reflection (TIR) is important in optical transducers.
The phenomenon known as ______ Internal Reflection (TIR) is important in optical transducers.
Signup and view all the answers
Calorimetric transducers measure the heat produced by the reaction, using the formula ΔT = nΔH/cp, where ΔH represents the ______.
Calorimetric transducers measure the heat produced by the reaction, using the formula ΔT = nΔH/cp, where ΔH represents the ______.
Signup and view all the answers
The Quartz crystal microbalance (QCM) utilizes the ______ Effect to measure mass changes.
The Quartz crystal microbalance (QCM) utilizes the ______ Effect to measure mass changes.
Signup and view all the answers
Sauerbrey proved that the oscillation frequency of the quartz crystal is dependent on the ______ change.
Sauerbrey proved that the oscillation frequency of the quartz crystal is dependent on the ______ change.
Signup and view all the answers
Cantilever-based sensors are a type of ______ free biosensor that is simple and cost-effective.
Cantilever-based sensors are a type of ______ free biosensor that is simple and cost-effective.
Signup and view all the answers
In mass sensitive sensors like QCM, the amount of mass accumulated on the surface affects the ______ frequency.
In mass sensitive sensors like QCM, the amount of mass accumulated on the surface affects the ______ frequency.
Signup and view all the answers
In enzyme-catalyzed reactions, considerable heat evolution can range from 5 to ______ kJ/mol.
In enzyme-catalyzed reactions, considerable heat evolution can range from 5 to ______ kJ/mol.
Signup and view all the answers
Cantilevers bend as a result of specific ______ occurring on their surface.
Cantilevers bend as a result of specific ______ occurring on their surface.
Signup and view all the answers
Study Notes
Transducers
- A device that converts variations in a physical quantity (e.g., pressure, temperature, brightness) into an electrical signal, or vice versa.
- In a biosensor, the transducer converts biochemical interactions into measurable electrical signals.
-
Types of Physical Quantities Converted:
- Thermal: temperature, heat flow
- Mechanical: position, acceleration, force, pressure
- Chemical: concentration, composition, reaction rate
- Optical: intensity, wavelength, polarization
- Magnetic: field intensity, flux
- Electrical: voltage, current, charge
Sensors and Actuators
- Sensors: Devices that convert a physical parameter into an electrical output.
- Actuators: Devices that convert an electrical signal into a physical output.
Electrochemical Biosensors
- Detect electrochemical reactions at the electrode-electrolyte interface.
-
Types:
- Potentiometric
- Amperometric
- Conductometric
Amperometric Transduction
- Electrode potential is maintained at a constant level for oxidation/reduction.
- Current flow is proportional to the analyte concentration.
- Prone to interference by exogenous oxygen.
- Commonly utilizes enzyme electrodes based on oxidases, combined with hydrogen peroxide indicators.
Increasing Selectivity in Amperometric Transduction
- Using membranes: examples include cellulose acetate, Nafion, polycarbonate
- Using mediators: artificial electron acceptor molecules facilitate electron transfer from enzyme to electrode.
- Using metallised electrodes: electrodeposition of noble metals (platinum, palladium, rhodium, ruthenium) creates highly catalytic surfaces.
- Using polymers: polymers can prevent interfering species from reaching the electrode surface (e.g., polypyrrole).
Potentiometric Transduction
- Monitors potential (relative to a reference) under zero current conditions.
- Potential is directly proportional to the logarithm of the analyte concentration.
- Ion-selective electrodes are used to measure changes in ion concentration.
- Example: pH electrode.
ISE (Ion Selective Electrode)
- Polymeric membrane electrodes are commercially available.
- Used to selectively detect ions in complex biological matrices (e.g., K+, Na+, Ca2+, NH4+, H+, CO32-).
Noninvasive Alcohol Monitoring System
- Wearable tattoo-based system uses iontophoresis to deliver pilocarpine and induce sweat.
- Analyzes sweat for ethanol concentration using alcohol oxidase enzyme and Prussian Blue electrode.
- Offers highly selective and sensitive detection of ethanol.
Other Biosensor Types (with examples)
- Calorimetric: Measures heat produced during a reaction. (Examples: Catalase on hydrogen peroxide, Cholesterol oxidase on cholesterol)
- Optical: Uses light for transduction. (Examples: photonic crystals, SPR, fluorescence resonance energy transfer (FRET).
- Mass sensitive (QCM): Measures mass changes based on frequency changes in a piezoelectric quartz crystal.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores the concepts of transducers, sensors, and actuators, focusing on how they convert various physical quantities into electrical signals. Additionally, it delves into different types of electrochemical biosensors and their operational principles. Test your knowledge on these essential technologies and their applications.
