Biosensors & it’s applications.

Submitted by :-Kumar virbhadra

Introduction

A biosensor is an independently integrated receptor transducer device, which is capable of providing selective quantitative or semi-quantitative

analytical information using a biological recognition element.(IUPAC recommendations 1999)

Professor Leland c Clark junior (1918-2005) is called the father of biosensor. The inventor of the Clark electrode, a device used for

measuring oxygen in blood, water and other liquids. Biosensors play a part in the field of environmental quality, medicine and

industry mainly by identifying material and the degree of concentration present.

Schematic representation of a Biosensor.

Few examples.

Infectious disease(T.B.) biosensor by

RBS(Rapid Biosensor Systems).

Pregnancy test (detects hCG protein in urine.

Glucose monitoring device.

Few more examples.

Artificial limb biosensor.

Toxicant sensing

Few more examples.A microbial biosensor for the detection of bioavailable mercury. When bioavailable mercury is present in the environment of the sensor cell (blue oval)it enters the cell and induces the meR promoter (green). When the promoter is induced it direct the biosynthesis of the enzymes that mediate bioluminescence and as a result the biosensor emits light (stars).

Glucose Biosensor(A review).

Classification of Biosensors :-

Some sensing techniques used in Biosensors :-

1. Florescence.2. Chemi-luminescence.3. Surface Plasmon resonance (SPR) - In principle, when the SPR biosensor

is exposed to any changes, it will induce changes in the refractive index which used to measure or observed the reaction.

4. Conductometric.(Based on electrolytic conductivity which depends on ionic concentration)

5. Amperometry- Amperometric sensor are based on the measurement of current as a function of time resulting from the oxidation and reduction of an electro active species in a biochemical reaction.

Basic steps involved in working of a Biosensor :-

1. The analyte (Molecule - Protein, toxin, peptide, vitamin, sugar, metal ion).

2. How to deliver the analyte to the sensitive region?((Micro) fluidics - Concentration (increase/decrease), Filtration/selection.)

3. Detection/Recognition.(How to specifically recognize the analyte?)4. Signal generation.(By Transducer)5. Signal detection.(By detectors)6. Display of result.(Numerical or Statistical)

Potential applications :-

Conclusion :-

The past decade has seen great advancements in the field of biosensor along many fronts.

This dynamic tool has been applied in many area of life science research, health care, environmental, food and military application.

Biochip is a promising candidate for label free, reagent less, real time monitoring, miniaturization and low cost application.

For medical application, this cost advantage will allow the development of extremely low cost, disposable biochips that can be used for in-home medical diagnostics of diseases without the need of sending samples to a laboratory for analysis which time consuming.

References:-

Abdulhalim I, Zourob M, Lakhtakia A. Overview of Optical Biosensing Techniques. In Marks RS, Lowe CR, Cullen DC, Weetall HH, Karube I (ed): Handbook of Biosensors and Biochips. Wiley, Weinheim 2007.

Acha V, Andrews T, Huang Q, Sardar DK, Hornsby PJ. Tissue-Based Biosensors. In Zourob M (ed): Recognition receptors in biosensors. Springer, New York 2010, pp. 365382.

Berdat D, Marin A, Herrera F, Gijs MAM. DNA biosensor using fluorescence microscopy and impedance spectroscopy. Sens Actuators B Chem. 118: 53–59, 2006.

Liu CC. Electrochemical Based Biosensors. Biosensors. 2: 269–272, 2012. Teles F, Fonseca L. Trends in DNA biosensors. Talanta. 77: 606–623,

2008.

Thank you.