Biosensors

What is biosensor?

Biosensors: are analytical tools for the analysis of bio-material samples to gain an understanding of their bio-composition, structure and function by converting a biological response into an electrical signal. The analytical devices composed of a biological recognition element directly interfaced to a signal transducer which together relate the concentration of an analyte (or group of related analytes) to a measurable response.

Biosensor Components

Schematic diagram showing the main components of a biosensor. The bio-reaction (a) converts the substrate to product. This reaction is determined by the transducer (b) which converts it to an electrical signal. The output from the transducer is amplified (c), processed (d) and displayed (e).(http://www.lsbu.ac.uk/biology/enztech/biosensors.html)

Why are Biosensors Important?

Biosensors are;• important tools in food safety, diagnostics,

medical monitors, and detection systems for biological warfare agents.

• important devices offering analytical simplicity both in and outside the analytical laboratory.

• selective, rapid and sensitive instruments for determination of chemical and biochemical targets

Market Size of Biosensors

$7.3 Billion in 2003 $10.2 Billion in

2007 with a growthrate of about 10.4%

History of BiosensorsProfessor Leland C Clark Jr = the father of the biosensorIn 1956, Clark published his definitive paper onthe oxygen electrode.

In 1962, he described "how to makeelectrochemical sensors more intelligent" byadding "enzyme transducers as membraneenclosed sandwiches”.

In 1975, YSI (Yellow Spring Instruments Co., Ohio, USA ) produced the first of many biosensor-based laboratory analysers to be built by companies around the world.1918–2005

The picture was received from the artical of Prof. W. R. Heineman and W. B. Jensen in Biosensor and Bioelectronics (2006, 21, 1403-1404)

History of Biosensors

In 1987, a pen-sized meter for home blood-glucosemonitoring formed the basis for the screen-printedenzyme electrodes launched by MediSense (Cambridge,USA). The electronics have since been redesigned into popularcredit-card and computer-mouse style formats, andMediSense's sales showed exponential growth, reaching$175 million per annum by 1996, when they werepurchased by Abbott

The idea of building directimmunosensors by fixing antibodies to apiezoelectric or potentiometric transducerhad been explored since the earlyseventies, but it was a paper by Liedberget al. The BIAcore (Pharmacia, Sweden)produced commercial model of thistechnology in 1990.

Principle of Electrochemical Biosensor

Electrochemical Glucose Biosensor

What are new trends?

Lab-on-a-Chip

References

• http://www.etsia.upv.es/Internacional/Seminarios/Curso%2006_07/sesion7/Biosensors.pdf

• http://nanohub.org/resources/2261/download/nanobiotechnology%20and%20biosensors.pdf