Biosensor is a device that consists of the biological sensing element and detects biological or chemical reactions by generating signals proportional to the concentration of an analyte in the reaction. These devices utilize the sensitivity and selectivity of biomolecular interactions and couple them to the sensitive measurement technology. Biosensors are widely applied in various analytical measurements including biomedical applications, disease diagnosis, food analysis, drug analysis, environmental monitoring, and defense and security applications.
A typical biosensor consists of the following components:
- Analyte: A substance of interest that needs to be investigated. For instance, glucose is an “analyte” in a biosensor intended to detect glucose.
- Bioreceptor: A bioreceptor is a molecule that uniquely recognizes the analyte. Bioreceptors include things like enzymes, cells, aptamers, deoxyribonucleic acid (DNA), and antibodies. Bio-recognition is the process of signal production (in the form of light, heat, pH, charge or mass shift, etc.) in response to the contact of the bioreceptor with the analyte.
- Transducer: An element known as a transducer transforms one type of energy into another. The transducer’s function in a biosensor is to transform a bio-recognition event into a quantifiable signal.
- Electronics: This section of a biosensor is responsible for processing the transduced signal and getting it ready for display. It is made up of complicated electrical circuitry that carries out signal conditioning tasks like signal amplification and conversion from analog to digital form. The biosensor’s display device then quantifies the signals that have been processed.
- Display: The display comprises a user interpretation system that provides readable figures or curves for the user, like a computer’s liquid crystal display or a direct printer. This component frequently consists of a hardware and software combination that produces user-friendly biosensor findings. Depending on the needs of the end user, the output signal on the display may be numerical, visual, tabular, or even a picture.
Principle of Biosensor
A particular enzyme or preferred biological substance is typically deactivated via some of the common ways, and the deactivated biological substance is in close proximity to the transducer. The biological object and the analyte interact to create a clear analyte, which in turn produces an electronic response that can be computed. In some instances, the analyte is switched to a component that could be linked to a source of heat, gas discharge, electron ions, or hydrogen ions. The transducer in this can affect the connected device by converting it into electrical signals that may be changed and measured.
Characteristics of Biosensor
- Selectivity
- Reproducibility
- Stability
- Sensitivity
- Linearity
Biosensors Nanotechnology
Nanotechnology has greatly benefited biosensor device development. Nanomaterials have been used to enhance signals or increase detection rates in analytical equipment to increase their sensitivity. To improve current density, carbon nanotubes have been used in a number of different ways. Gold and silver nanoparticles are among the other nanomaterials that are most frequently employed in biosensing applications. Electrodes modified with nanoparticles, graphene sheets, and carbon nanotubes perform better than unmodified electrodes since they possess more conductivity, surface area, and electroactivity. Several biosensors for households are available. Some common examples are pregnancy test kits, glucose sensors, etc. The most common biorecognition reactions are antibody-antigen binding, DNA hybridization, protein DNA binding, protein aptamer binding, and protein-protein binding
Application of Biosensors
The primary purpose of a biosensor device, which combines a biological component and a physiochemical detector, is to detect analytes. It possesses a wide range of applications as listed below:
- Identification of biomolecules that are either disease markers or pharmacological targets.
- Platforms for monitoring food quality, safety, and nutritional content can be used with biosensors.
- For monitoring the quality of air and water
- Veterinary and agricultural applications
- Screening of diseases
- Detection of crime
- Development of drugs
- Diagnosis of disease
- Insulin treatment
- Industrial & Environmental Applications
