The term “biosensor” was coined by Cammann, and its definition was introduced by IUPAC.
Biosensors are analytical devices that convert a biological response into an electrical signal.
The materials used in biosensors are categorized into three groups based on their mechanisms:
Biocatalytic group comprising enzymes
- Enzyme biosensors have been devised on immobilization methods, i.e. adsorption of enzymes by van der Waals forces, ionic bonding or covalent bonding.
- The commonly used enzymes for this purpose are oxidoreductases, polyphenol oxidases, peroxidases, and amine oxidases.
Bioaffinity group including antibodies and nucleic acids
- Immunosensors were established on the fact that antibodies have a high affinity towards their respective antigens, i.e. the antibodies specifically bind to pathogens or toxins, or interact with components of the host’s immune system.
- The DNA biosensors were devised on the property that single-strand nucleic acid molecule is able to recognize and bind to its complementary strand in a sample. The interaction is due to the formation of stable hydrogen bonds between the two nucleic acid strands.
- Nucleic acid-based sensing systems are more sensitive than antibody-based detection methods as they provide gene-based specificity, without utilizing amplification steps to attain detection sensitivity to the required levels.
Microbe-based containing microorganisms.
- A microbial biosensor is a biosensor that uses microorganisms which consists of numerous enzymes as the bioelements.
- The enzymes in the living cells can produce a response to the analytes specifically and selectively, without neither the necessity of time-consuming and costly purification nor the negative effects of the operating environment.
APPLICATIONS OF BIOSENSORS
Some of the popular fields implementing the use of biosensors are food industry to keep a check on its quality and safety, to help distinguish between the natural and artificial; in the fermentation industry and in the saccharification process to detect precise glucose concentrations; in metabolic engineering to enable in vivo monitoring of cellular metabolism.
Applications of Biosensors in a nutshell
- In food processing, monitoring, food authenticity, quality, and safety)
- In fermentation processes
- Biosensing technology for sustainable food safety
- In the medical field
- Biodefense biosensing applications
- In metabolic engineering
- Biosensors in plant biology
ROLE IN MODERN MEDICINE
Biosensors and their role in medical science including early stage detection of human interleukin-10 causing heart diseases, rapid detection of human papillomavirus, etc. are important aspects. Fluorescent biosensors play a vital role in drug discovery and in cancer.
a) Glucose biosensors are widely used in clinical applications for diagnosis of diabetes mellitus, which requires precise control over blood-glucose levels.
b) A promising biosensor technology for urinary tract infection (UTI) diagnosis along with pathogen identification and anti-microbial susceptibility is under study.
c) A novel biosensor, based on hafnium oxide (HfO2), has been used for early-stage detection of human interleukin (IL)-10.
d) Quantitative measurement of cardiac markers in undiluted serum
e) Immunosensor array for clinical immunophenotyping of acute leukemias
f) Biochip for quick and accurate detection of multiple cancer markers
Article Reference-https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862100/ Image courtesy-DoD graphic illustration by Jessica L. Tozer/Released