A biosensor is an analytical tool that detects a biological response and converts it into an electrical signal. It consists of a biological recognition element, like an enzyme or antibody, connected to a transducer that detects the concentration of an analyte. Biosensors can detect molecules, proteins, toxins, and more. They are used for applications like medical diagnosis, food analysis, environmental monitoring, and more. Some examples are pregnancy tests and glucose monitors. Biosensors offer advantages like low cost, simplicity, and rapid response times.

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BIOSENSOR
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2. What is a Biosensor?

3. 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.

4. 1. The Analyte (What do you want to detect)
Molecule - Protein, toxin, peptide, vitamin, sugar,
metal ion
2. Sample handling (How to deliver the analyte to the
sensitive region?)
(Micro) fluidics - Concentration increase/decrease),
Filtration/selection
Biosensor

5. 3. Detection/Recognition
(How do you specifically recognize the analyte?)
4. Signal
(How do you know there was a detection)
Biosensor

6. A biosensor can include, for example, an enzyme, an antibody, or
a microorganism that in turn is connected to an electronic element
A typical design of an enzyme modified electrochemical biosensor

7. Example of biosensors
Pregnancy test
Detects the B HCG protein in urine
Glucose monitoring device (for diabetes patients)
Monitors the glucose level in the blood.
Infectous disease biosensor from RBS

8. Father of the Biosensor
Professor Lland C Clark Jnr 1918–2005

9. Application of Biosensor
Food Analysis
Study of biomolecules and their interaction
Drug Development
Crime detection
Medical diagnosis (both clinical and laboratory use)
Environmental field monitoring
Quality control
Industrial Process Control
Detection systems for biological warfare agents
Manufacturing of pharmaceuticals and replacement
organs

10. * biosensors are being more useful and having more usage areas day by
day and having more new markets such as security, military biodefense,
environmental monitoring, and the process industry.
* Biosensors are specific due to the immobilized system used in them
* Rapid and continuous control is possible with biosensors
* Response time is short (typically less than a minute) .
*It help to fight cronic deseases and reduce the helth care cost.
* These systems offer some advantages such as low cost, simple design or
small dimensions.
* Practical

11. Figure 1. Schematic diagram of a calorimetric biosensor. The sample stream (a)
passes through the outer insulated box (b) to the heat exchanger (c) within an
aluminium block (d). From there, it flows past the reference thermistor (e) and into
the packed bed bioreactor (f, 1ml volume), containing the biocatalyst, where the
reaction occurs. The change in temperature is determined by the thermistor (g) and
the solution passed to waste (h). External electronics (l) determines the difference in
the resistance, and hence temperature, between the thermistors.

12. A potentiometric biosensor can be defined as a device containing a biological sensing
element connected to an electrochemical potential transducer. Potentiometric biosensors
usually depend on a biochemical reaction .
Figure 2. A simple potentiometric biosensor. membrane (a) surrounds the
biocatalyst (b) next to the active glass membrane (c) of a pH (d). The
electrical potential (e) is generated between the internal Ag/AgCl electrode (f)
bathed in dilute HCl (g) and an external reference electrode (h).

13. The enzyme urease is immobilized at the surface of the ISE and catalyzes the
hydrolysis of urea to NH3 and CO2.
The product ammonia is hydrolyzed to form NH4 .
which is observed by the ISE.
The signal generated by
the NH4 + produced is related to the concentration
of urea in the sample
urease
Urea 2NH3 + CO2

14. Overview: the reduction & Oxidation of certain chemical species when being
under the power of electrical potential help to measure of special analytes.
Principle:
When provided with a constant potential , the analyt bound to the receptor with
undergo an Oxidation Reduction Reaction , that can be quantified by
measuring the electron exchange from working electrode ( Anode) to the
counter electrode ( Cathode) .
This electron exchange , or current is limited by the diffusion (spreading) of
analyte through a selectively and absorbent membrane and various boundary-
layer phenomena, will be relative to the concentration of the target analyte

15.  YSI : Glucose/Lactate
 D-glucose is oxidized in the presence of glucose oxidase, producing
hydrogen peroxide and glucono-lactone.
 Prostate specific antigen (PSA)

16. [1]Cutler et al. ‘Optical Biosensors Final Report Spring Semester 2009’
 [2] Gabrovska et al . ‘Immobilization of urease on nanostructured polymer membrane
and preparation of urea amperometric biosensor’
 [3] Reyes De Corcuera et al ‘ Biosensors’
 [4] http://whatis.techtarget.com/definition/sensor
 [5] http://www.springerreference.com/docs/html/chapterdbid/332539.html
 [6] Paul et al ‘Biosensors in clinical chemistry’
 [7] http://www.ysilifesciences.com/index.php?page=how-does-the-ysi-sensor-technology-
work
 [8] http://www.lsbu.ac.uk/water/enztech/potentiometric.html
 [9]

17. A sensor is a device that detects and responds to some type of input from
the physical environment. The specific input could be light, heat, motion,
moisture, pressure, or any one of a great number of other environmental
phenomena.
example
Motion sensors in various systems including home security lights, automatic
doors