1. Biosensors

2. 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.

3. 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). (

4. 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

5. Market Size of Biosensors
$7.3 Billion in 2003
$10.2 Billion in
2007 with a growth
rate of about 10.4%

6. History of Biosensors
Professor Leland C Clark Jr = the father of the biosensor
In 1956, Clark published his definitive paper on
the oxygen electrode.
In 1962, he described "how to make
electrochemical sensors more intelligent" by
adding "enzyme transducers as membrane
enclosed 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, )

7. History of Biosensors
In 1987, a pen-sized meter for home blood-glucose
monitoring formed the basis for the screen-printed
enzyme electrodes launched by MediSense (Cambridge,
USA).
The electronics have since been redesigned into popular
credit-card and computer-mouse style formats, and
MediSense's sales showed exponential growth, reaching
$175 million per annum by 1996, when they were
purchased by Abbott
The idea of building direct
immunosensors by fixing antibodies to a
piezoelectric or potentiometric transducer
had been explored since the early
seventies, but it was a paper by Liedberg
et al. The BIAcore (Pharmacia, Sweden)
produced commercial model of this
technology in 1990.

8. Principle of Electrochemical Biosensor

9. Electrochemical Glucose Biosensor

12. What are new trends?

13. Lab-on-a-Chip

15. References