Biosensors

In easy words a biosensor can be defined as a device which measures biological or chemical reactions by producing certain signals which would be proportional to the concentration of the analyte in the reaction. 

Uses of biosensor can be:-

• Monitoring diseases
• Discovering drugs and their presence in the human body.
• Pollution detection in an area.
• For detection of microorganisms which cause disease.

It is actually the short form of a biological sensor. The two logical substances like an enzyme, antibody or nucleic acid are present inside the biosensor. This substance then communicates using the analyte to be checked and the reply can be varied into an electrical signal using a transducer present inside the biosensor.

Biosensor and Bioelectronics

Biosensor and Bioelectronics is a scientific journal worked on by a number of scientists and was published by a netherland-based publishing company named Elsevier. It shares the research regarding biosensors and bioelectronics.

Firstly, I. John Higgins of Cranfield University established the journal in 1985. Along with him were W. Geoff Potter of the Science and Engineering Research council and Anthony P.F. Turner of Cranfield University. Three of these scientists became the editor – in- chief   till their retirement in the year 2019. 

The impact factor of the journal was 10.618 in 2020. On the other hand the 5 year Impact was summed up to be 9.323.

Components of a Biosensor.

The components of a Biosensor are as follows-

• Analyte – It is the substance which requires the detection. Eg- Glucose would be an analyte inside a biosensor which detects glucose.
• Bioreceptors/Sensitive biological element – It is the molecule which recognises the analyte. When the bioceptor and the analyte interact with each other, it is known as bio recognition. Eg :tissue, microorganisms, organelles, cell receptors, enzymes, antibodies, nucleic acids. 
• Transducer- It is the element which converts the energy from one form to another. It converts the biorecognition process into a measurable signal of energy.
• Electronics- It is the part in a biosensor, which changes the signal of the transducer and makes it ready for display.
• Display – It can be any display device for displaying visual curves which can be understood by the user of the biosensor.

Types of biosensors 

 There are few types of biosensors. The biosensors are as follows- 

• Amperometric Biosensor – This type of biosensor works on the basis of the quantity of current released during oxidation. Its main advantage is that it provides exact quantitative analytical information. It gives the result based on the current flow and its amount  between the Counter Electrode. It also uses the Redox response during its operation. Uses of the biosensor are medical screening, quality control etc.

• Potentiometric Biosensor- It gives a reply in logarithm, the high energy Ranges. It is made up of two electrodes which are responsive. These help in the analytical recognition. 

Eg- ISE (Ion-Selective Electrodes), ISFET (Ion-selective Field Effect transistors). It is a field-effect transistor which is used for measuring the concentration of the ions in the solution. The current through the transistor will only change according to the changes in the ion’s concentration. 

• Impedimetric Biosensors- It is a response indicator used for indicating physical and chemical properties. Currently this type of biosensors are trending. It is used for recording catalysed response of enzyme lectines, receptors etc.

• Voltammetric Biosensors – It is the type of biosensor used for observing acrylamide. It is made using a carbon glue electrode which has haemoglobin

• Optical biosensors – These follow the phenomenon of surface plasmon resonance (SPR) techniques. It works by using other materials properties This utilises certain properties of the other materials, for example a thin layer of gold placed on a glass with very high refractive index and the surface can absorb laser light, this produces electron waves or surface plasmons on the gold surface.

• Electrochemical Biosensors – Electrochemical biosensors are those biosensors which follow the enzymatic catalysis of a reaction which either produces or consumes electrons These enzymes are called redox enzymes. 

Conclusion

We learnt that a biosensor is an integrated receptor-transducer device. It converts biological response to an electric signal.

It uses a biologically sensitive substance to detect chemical presence in the substance. Nowadays, we have sensors around us. Any electronic device we use  has some kind of a sensor in it. Mainly biosensors are used in a large variety of detections. Biosensors can be used for checking our atmospheric oxygen levels and can also be used for detecting certain substances in the food industry. So we can understand the importance of biosensors in our lives at this moment. Some journals like the biosensors and bioelectronics shed light on biosensors and their working. Even after so many discoveries and inventions regarding the biosensors, we should push forward towards modernisation. We can conclude knowing about the facts of biosensors, its components, its examples and the types of biosensors.