BIOSENSOR

#Environment biotech #Biosenser #Application Of Biosensor #Principle of Biosensor

Biosensors show the potential to complement laboratory based analytical methods for environmental applications. In recent years, growing number of initiatives and legislative actions for environmental pollution control have been adopted. In this respect, biosensors have demonstrated a great potential in recent years and thus arise as proposed analytical tool for effective monitoring. A biosensor is defined by IUPAC as a self-contained integrated device that is capable of providing specific quantitative or semiquantitative analytical information using a biological recognition element.

PRINCIPLE OF BIOSENSOR

Ecology tells us that each organism grows in a specific set of conditions i.e. niche that can be defined in terms food, temperature, moisture, pH, etc.one can use each organism as a biosensor for a set of conditions. A biosensor is an analytical device composed of biological sensing element (enzyme, receptor antibody or DNA) in intimate contact with a physical transducer (optical, mass or electrochemical) which together relate the concentration of an analyte to a measurable electrical signal. A biological sensing element may be paired with a physical transducer.

Biosensors are operated based on the principle of signal transduction. The bio-recognition element, essentially a bio receptor, is allowed to interact with a specific analyte. The transducer measures this interaction and outputs a signal. The intensity of the signal output is proportional to the concentration of the analyte. The signal is then amplified and processed by the electronic system.

Principle of Biosensor

TYPES OF BIOSENSORS

Based on the method of transduction, Biosensors are divided into three types:

1. Piezoelectric Biosensors

These biosensors are also known as Acoustic Biosensors as they are based on the principle of sound vibrations i.e. acoustics. When a mechanical force is applied on a piezoelectric biosensor, they produce an electrical signal. The biological elements are attached to the surface of the piezoelectric biosensor. The piezoelectric biosensor, which is essentially a mass to frequency converter, converts the mechanical vibrations of the sensing molecules into proportional electrical signals.

2. Electrochemical Biosensors

In electrochemical biosensors, the biological molecules are coated onto a probing surface. The sensing molecules are held in place with the help of non-interfering membrane. Then, the sensing molecules react appropriately to the compound to be detected and produces an electrical signal proportional to the quantity being measured.

3. Optical Biosensors

Optical Fibers play an important role in Optical Biosensors. The optical fibers allow detection of the sensing elements based on the different properties of light like absorption, scattering and fluorescence.

The reaction causes changes in either of the above mentioned properties as a result of the change in the refractive index of the interacting surface. One of the main advantages of using optical biosensors is their non-electrical nature. This allows them to analyze multiple elements on a single layer just by varying the wavelength of the light.

ADVANTAGES OF BIOSENSORS OVER CONVENTIONAL ANALYTICAL TECHNIQUES

Some of the major advantages of biosensors are:

· Portability

· Miniaturised sensors

· Works on-site

· Ability to measure pollutants in complex matrices

· Minimal sample preparation

APPLICATIONS OF BIOSENSORS

1. Medicine, Clinical and Diagnostic Applications

 The main area of interest of Biosensor is the Medicine, Clinical and Diagnostics

applications. Electrochemical based Biosensors are commonly used in biochemical labs

and clinics to monitor and measure glucose levels as well as lactic acid.

 Commercial Biosensor in the field of personal health care are becoming quite popular,

especially, self-monitoring of blood glucose. The main advantage of this method is the

blood samples cannot be contaminated and also it is undiluted for more accurate results.

 Earlier self-monitoring devices are one-time use applications i.e. test can be performed

for a single time and the sensor must be disposed after that. But advances in this field

allows, reusable sensors for improved patient care.

 Example: biosensors to measure blood glucose levels are made of copper oxide (Cu2O).

2. Environmental Monitoring

 One of the major application of Biosensor is in the field of Environmental Pollution

Monitoring. Especially, water pollution monitoring is an area where Biosensors have

substantial advantage. There are numbering pollutants that are contaminating ground

water and as a result the quality drinking water is getting worse.

 Biosensors with sensing elements for nitrates and phosphates are becoming common for

battling water pollutants.

 Another important application is for the military to detect chemicals and hazardous

biological specimens that can be used as bio-weapons.

Biosensors used for nitrogen compounds determination

3. Industrial Applications

 Fermentation is a large industrial operation used in dairy, alcohol and other similar

products. Large scale Bacteria and cell culture must be maintained for this purpose. In

order to minimize the cost of production and risk free fermentation, it is essential to

monitor these delicate yet expensive processes.

 Biosensors are designed to monitor and measure the generation of a fermented product.

4. Food Industry

 Biosensors are used in food industry for food quality control for measurement of amino

acids, carbohydrates, alcohols, gases, etc..

 These can be to measure carbohydrates, alcohols and acids, for example, during quality

control processes. The devices may also be used to check fermentation during the

production of beer, yoghurt and soft drinks.

 Another important application is their use in detecting pathogens in fresh meat, poultry or

fish.

5. Agriculture Industry

 Biosensors in the field of agriculture are generally used for detection of pesticides.

Biosensors used in detection of herbicides

Thankyou !!!

Biosensor | Online Biotech Notes