BIOSENSORS as a tool for biomonitoring

Mallesh BAEM-08

– Hazardous wastes contaminates our

environment.

– Continuous exposure of life to these

contaminants.

– Increasing health problems.

– Need to monitor wider range of analytes in air,

water and soil.

– Characterization the hazardous wastes.

–  Several methods available.

what is biomonitoring…?

• Use of a biological entity as a detector and its

response as a measure to determine

environmental conditions.

• The use of living organisms to test the suitability

of effluents for discharge into receiving waters.

• Biomonitoring is a collective term for all the

techniques that use living organisms to provide

information about both abiotic (non-living) and

biotic (living) components of an environment.

Definition

Biomonitoring is a scientific technique for assessing

human exposures to natural and synthetic

chemicals, based on sampling and analysis of an

individual's tissues and fluids.

Biomonitoring is defined as the measurement and

assessment of work place agents or their

metabolites either in tissues, secreta, excreta, or

any combination of these systems in

occupationally exposed human subjects.

Principle

The fundamental principle of biomonitoring is that

living organisms reflect the conditions in which

they live, and so a change in some aspect of the

biota implies a change of some sort in the

environment from which the organisms came.

Biomonitoring

The process of biomonitoring involves three steps:

(1) Selecting who will be monitored as well as when

and where,

(2) Collecting tissue and/or fluid samples, and

(3) Deciding which chemicals to study and

analyzing for those chemicals in the samples

that are collected.

• The blood, urine, breast milk and expelled air are

most commonly measured

• Hair, nails, fat, bone and other tissues may also

be sampled.

• Biomonitoring only measures exposure; it does

not provide information about toxicity or risk.

• The laboratory techniques available for

biomonitoring are time conumable,

• This is a complex and expensive process.

SO WHAT WE NEED?

• A scientific tool.

• Can identify the contaminants faster.

• Cost effective.

• Can be operated in field itself.

• More efficient.

which is the alternate

option?

BIOSENSORS???

What we discus about…

What are biosensors

definition

Principle of biosensors

What are the Components

How does they work

Ideal biosensors

Types

Applications

Applications in biomonitoring

What are biosensors– Devices either used to monitor living systems or

incorporating biotic elements

– Biophysical devices which can detect the

presence of specific substances.

– Combines advances in biotechnology,

nanotechnology and information processing.

– Also capable of measuring the quantities of these

specific substances in the environment.

DEFFINITION

A device that uses specific biochemical reactions

mediated by isolated enzymes, immunosystems,

tissues, organelles or whole cells to detect

chemical compounds usually by electrical,

thermal or optical signals.

0r

The term biosensor is defined as a sensor

incorporating biological elements such as

enzymes, antibodies, receptors proteins, nucleic

acids, cells, or tissue sections - as the

recognition element, coupled to a transducer.

PRINCIPLE– The biological material is immobilized and a contact

is made between the immobilized biological material and the transducer

– The analyte binds to the biological material to form a bound analyte which in turn produces the electronic response that can be measured.

– Sometimes the analyte is converted to a product which could be associated with the release of heat, gas (oxygen), electrons or hydrogen ions. The transducer then converts the product linked changes into electrical signals which can be amplified and measured

Principle of biosensor

COMPONENTS

The two main elements in a biosensor

are:-

1. A biological recognition element and

2. A signal transducer.

And also…

a. Electronic amplifier.

b. Signal processing.

c. Presentation of sensor response

a. biorecognition element immobilized on a matrix.b. transducer.c. electronic amplifier. d. signal processing.e. presentation of sensor response.

HOW DOES THEY WORK

– Biosensors basically involve the quantitative

analysis of various substances by converting

their biological actions into measurable

signals.

– Generally the performance of the biosensors is

mostly dependent on the specificity and

sensitivity of the biological reaction, besides

the stability of the enzyme.

Analyte

Sample handling/preparation

DetectionSignal

Analysis

Response

IDEAL BIOSENSORS

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

TYPES

Based on bioreceptors Enzyme biosensor Microbial biosensor Affinity biosensor

Based on transducer Potentiometric Amperometric conductometric Optical

Acoustic or piezoelectric etc.

APPLICATIONS

Medical and health care

Industrial process control and safety

Environmental (air, water, soil)

Military(defense and security)

For biomonitoring

• To detect presence of toxicants in living system.

• To study the level of pollutants in the living

system.

• To characterize the contaminants in the body.

Ex;-

Whole-cell-based biosensors

Luminescent bacterial biosensor

Enzyme biosensors etc…

Biomonitoring can be useful to:

Determine which chemicals get into members of the

general population and at what concentrations

Determine if exposure levels are higher in some

groups than in others

Track trends in levels of exposure over time

Assess the effectiveness of public health efforts to

reduce exposure

Establish reference ranges for chemicals in the

body

Determine the prevalence of people with levels

above known toxicity thresholds

Set priorities for research on human health effects

?UESTIONS