By: Devika Rao
A biosensor is a type of analytical instrument that is made to detect changes that happen in biological processes and then turn those changes into electrical signals. Some examples of biological processes are enzymes, tissues, bavertai, acids, etc. The parts of a biosensor include a biological sensing element along with a transducer, which helps to convert the data into electrical signals. In addition to this, there is also a Signal Conditioning unit, a processor, or a Microcontroller including a Display unit, these make up the electronic circuit.
Image credit: Research Gate
The image above shows the three parts that make up a Biosensor, including the Biological Elements, Transducer, and Signal Processing.
There are five classifications used for a Biosensor. These include: (1) Electrochemical Biosensors, (2) Calorimetric/Thermal detection biosensors, (3) Optical biosensors, (4) Piezo-electric biosensors, and also (5) Resonant biosensors.
Electrochemical biosensors:
An electrode is a critical component in this sort of sensor, serving as a solid foundation for biomolecule immobilization and electron flow. The three types of electrodes typically used include the working electrode, reference electrode, and also counter or auxiliary electrodes. When there is a reaction that occurs between the analyte and the electors substrate, it is then considered a working electrode. There are three types of electrochemical biosensors, first, the Amperometric Biosensors, second, the Potentiometric Biosensors, and third, the Conductometric Biosensors.
Amperometric Biosensors:
These sensors are self-contained integrated devices that provide particular quantitative analytical information by measuring the current generated by the oxidation or reduction of an electroactive biological ingredient.
Potentiometric biosensors
This sensor is a device with a biological sensing element and an electrochemical potential transducer attached to it. This sensor can be used to calculate the analytical concentration of some analyte gas or solution components. When no voltage is present, these sensors measure the electrical potential of an electrode.
Conductometric biosensors
As a result of the biological process, these biosensors assess electrical conductivity in a sample solution between two electrodes.
Calorimetric/Thermal detection biosensors:
Calorimetric-based biosensors assess changes in heat, which can be used to calculate the extent of a reaction (for catalysts) or the structural dynamics of biomolecules in the dissolved state.
Optical biosensors:
A biorecognition sensing element is integrated with an optical transducer system in optical biosensors, which are small analytical equipment. An optical biosensor's primary goal is to provide a signal proportional to the concentration of a measured chemical (analyte).
Piezo-electric biosensors:
Piezoelectric biosensors are a type of analytical equipment that work on the basis of recording affinity interactions. A piezoelectric platform, also known as a piezoelectric crystal, is a sensor component that works on the premise of oscillations changing according to the presence of a mass on the piezoelectric crystal surface.
Resonant biosensors:
Resonant biosensors measure the vibrations of the electron cloud of a molecule. These biosensors are used to both qualitatively and quantitatively comprehend the functioning features of the human immunodeficiency virus (HIV).
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