Types of Biosensors | Working principle of Biosensor types
This article covers Biosensor types and biosensor working principle. It describes different types of Biosensors viz. Piezoelectric sensor,Electrochemical sensor and optical sensor.
Definition:The analytical device which is used for detection of analyte and combines it with physico-chemical detector or transduer is known as Biosensor. The figure-1 depicts working of such biosensor.
Following are the Biosensor types which are explained below.:
• Piezoelectric sensor
• Electrochemical sensor
• Optical sensor
Biosensor Working Principle
Figure-1: Biosensor working Principle
Biosensor consists of following components.
3. Electronics circuit and display
Following points summarize Biosensor working operation.
• It detects the input physical change due to biological element.
• The transducer element transforms the physical change into appropriate electrical signal.
• The electrical signal is amplified, processed and given to display in user desired format.
The biological material is im-mobilized by conventional methods. This immobilized biological material is in contact with the transducer. The analyte binds to biological material to form bound analyte. This consecutively produces electronic response which can be measured.
Different types of Biosensors | Biosensor Types
Biosensors can be categorized as per biological element or transduction element used. Biological elements typically used are enzymes, micro-organisms, antibodies, biological tissue, organelles etc. The method of transduction depends on type of physicochemical change as a result of sensing event. Primarily biosensors based on transducer element are mass based, electrochemical biosensors and optical biosensors.
• Mass based Biosensors include Magnetoelectric, Piezoelectric (QCM-Quartz crystal microbalance, SAW ) etc.
• Electrochemical Biosensors include potentiometric sensors, Amperometric sensors, Impedimetric sensors, conductometric sensors etc.
• Optical Biosensors include SPR (Surface Plasmon Resonance), Raman & FTIR, Fiber optics etc.
Following section describes working principle of different types of biosensors.
This mass based biosensors work based on acoustics principle i.e. sound vibrations. These sensors produce electrical signal based on applied mechanical force. In this mode, sensor modules are attached to piezo-electric surface which provide interactions between analyte and sensing molecules which set up mechanical vibrations. Here piezoelectric sensor functions as mass to frequency transducer which translates electrical signal in proportion to the amount of the analyte.
In this Biosensor type, membrane holds sensing molecules and excludes interfering species from analyte solution. The sensing molecules react with compounds to be detected which sparks electrical signal in proportion to concentration of analyte. Based on this working principle, the electrochemical biosensor employs potentiometric, amperometric and impedimetric transducers. They convert chemical information into measurable amperometric signal.
In this biosensor type, optical fiber allows detection of analytes on basis of absorption, fluorescence or light scattering. Optical biosensors allow multiple analytes to be detected by using different monitoring wavelengths. Various parameters such as changes in wavelength, time, wave propagation, intensity, distribution of spectrum or polarity of the light are used in optical biosensors for measurement purpose.
Following table mentions popular manufacturers of Biosensor.
|MediaTek||The company has introduced MT6381 Smartphone Biosensor for health measurements.|
|BioDot||Custom biosensor manufacturer|
|SD Biosensor, Inc.||South Korea|
|Telkonet, Inc.||Waukesha, WI|
|Pinnacle Technology, Inc.||Lawrence, KS|
|Eastprint, Inc.||North Andover, MA|