BIOSENSORS Group Members Laraib Satakzai……….....(26702) M Mateen Shahid…….....(26226)

Presented TO:- Sir. Owais Athar

Sensors:-A sensor is a converter that measures a physical quantity and converts it into a signal which can be read by an observer.

Bio Sensors:-A sensor that integrates a biological element with a physiochemical transducer to produce an electronic signal proportional to a single analyte which is then conveyed to a detector.

Bio sensors

A biosensor is an analytical device used for the detection of an analyte that combines biological component with a physicochemical detector.

It is a device which converts a biological response into an electrical signal. It detects, records, and transmits information regarding a physiological

change or process. It determines the presence and concentration of a specific substance in any

test solution.

History of Bio sensors Professor Leland C Clark Jnr. Is known as the father of the

biosensor Concept.

In 1956, Clark published his definitive paper on the oxygen

electrode. He wanted to expand the range of analytes that could

be measured in the body.

In 1962, he came up with the idea of more intelligent electrochemical sensors by adding enzyme transducers as membrane enclosed sandwiches.

In 1974, thermal transducers such as thermal thermistors were proposed.

In 1975, the idea of Clark came to reality. Glucose analyzer was lunched by Yellow Springs Instrument company,

In 1975, Lubbers and Opitz coined the term optode, which was a fiber-optic sensor with indicator to measure carbon dioxide or oxygen.

In 1976, Clemens incorporated an electrochemical glucose biosensor which was marketed with the name of Bio stator.

In 1976, the same year, La Roche introduced the Lactate Analyzer LA 640 . This is an important forerunner for lactate analyzers for sports and clinical application.

In 1982, Shichiri et al. reported in vivo application of glucose biosensors, which is the first needle-type enzyme electrode for subcutaneous implantation.

In 1984, A cited paper on the use of ferrocene and its derivatives as an immobilized mediator for use with oxidoreductases was published.

In 1987, a pen-sized meter for home blood glucose monitoring  was launched by MediSense.

In 1996,  the sale of this home blood glucose monitoring reached 175 million dollars.

History

Working Of Bio Sensors Bio sensors basically involve the quantitative analysis of various substances

by converting their biological actions into measurable signals.

Analyte diffuses from the solution to the surface of the biosensor.

Analyte reacts specifically and efficiently with the biological component of the biosensor.

This reaction changes the physicochemical properties of the Transducer surface.

This leads to a change in the optical/electronic properties of the Transducer surface.

The change in the optical/electronic properties is measured/converted into electrical signal, which is detected.

Working

Flow Diagram

Components of Bio sensors.

Components

Basic Characteristics1.Linearity:- Linearity of the sensor should be high for the detection of high

substrate concentration.

2.Sensitivity:- Value of the electrode response per substrate concentration.

3.Selectivity:- Chemical interference must be minimized for obtaining the correct result.

4.Response Time:- Time necessary for having 95% of the response

Types of Bio Sensors There are several types of Bio sensors. Some of them are discussed here shortly.

1. Optical Bio sensors

2. Calorimetric Bio sensors

3. Potentiometric Bio sensors

4. Piezo-Electric Bio Sensors

5. Electrochemical Bio sensors.

Types

This type of bio sensors uses light to detect the change. It is further classified into two types.

I. Colorimetric for color:

It measures change in light adsorption as reactants are converted to products.

II. Photometric For light intensity:

Photon output for a luminescent or fluorescent process can be detected with photomultiplier tubes or photodiode systems.

1-Optical Bio sensors.

2- Calorimetric Bio sensors: IT uses the absorption/Production of heat to detect the analyte.

If the enzyme catalyzed reaction is exothermic, two thermistors may be used to measure the difference in resistance between reactants and product and hence the analyte concentration.

Temperature is measured by enzymes thermistors.

The advantage is that it does not require frequent recalibration.

Uses:It is used in the detection of

Pesticides

Pathogenic bectaria.

Types

3- Potentiometric Bio sensors

Types

In this bio sensor change in distribution of charge is detected using ion-selective electrodes, such as pH meters.

When ramp voltage is applied to an electrode in solution, a current flow occurs because of electrochemical reactions.

Measured Parameter: Oxidation/reduction, Potential of an electrochemical reaction.

4- Piezo-electric Bio sensors

It uses gold to detect specific angle at which electrons waves are emitted when the substance is exposed to laser light/crystals like quartz, which vibrates under the influence of an electric field.

Change in frequency is proportional to Mass of absorbed material.

Many chemical reactions produce or consume ions or electrons which in turn cause some change in the electrical properties of the solution which can be sensed out and used as measuring parameter.

It is further classified into three types.

i. Amperometeric for applied current:- Movement of e- in redox reaction.

ii. Potentiometric for voltage: Change in distribution of charge.

iii. Conductrimeteric: Used for impedence

Uses:It is used in detection of Hybridized DNA, DNA-binding drugs and glucose concentration.

5- Electrochemical Bio sensorsTypes

Ideal Bio sensors. The output signal must be relevant to measurement environment.

The functional surface must be compatible with the transducer.

High specificity and selectivity (low interference).

Sufficient sensitivity and resolution.

Sufficient accuracy and repeatability.

Sufficient speed of response.

Sufficient dynamic range.

Insensitivity to environmental interference or their effects must be compensated.

Applications 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 replacements.

Applications

Environmental Monitoring

Military

Law Enforcement

Medical

Thank you