Volume 8 • Issue 1 • 1000235 J Biosens Bioelectron, an open access journal ISSN: 2155-6210 Review Article Open Access Journal of Biosensors & Bioelectronics J o u r n a l o f B i o s e n s o r s & B i o e l e c t r o n i c s ISSN: 2155-6210 Ali et al., J Biosens Bioelectron 2017, 8:1 DOI: 10.4172/2155-6210.1000235 *Corresponding author: Jazib Ali, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan, Tel: +923465449709; E-mail: jazibali10@yahoo.com Received November 24, 2016; Accepted January 18, 2017; Published January 28, 2017 Citation: Ali J, Najeeb J, Ali MA, Aslam MF, Raza A (2017) Biosensors: Their Fundamentals, Designs, Types and Most Recent Impactful Applications: A Review. J Biosens Bioelectron 8: 235. doi: 10.4172/2155-6210.1000235 Copyright: © 2017 Ali J, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Keywords: Transducer; Bioanalyte; Biosensors; Phage-sensor; Surface Plasmon Resonance (SPR) sensor; Amperometric sensor; Conductimetric sensor Introduction Sensors; their fundamentals and categorization Te word “sensor” fnd its origin from the Latin word “sentire” which basically means ‘to identify’ anything. By hearing this word sensor, the foremost thing that springs into our minds is the concept of basic fve human senses: ophthalmoception, audioception, gustaoception, olfacception and tactioception. Te working mechanism of these senses is generalized as a) reception of input signal by the sensory cells because of external stimuli b) conduction of data towards the brain for interpretation as neurological impulses c) receptors respond to the stimulus as per instructed by the interoperating center. With this brief explanation of sense, more methodical and technical defnition for sensor could be established which is as follows; it is a device that obtains and responds to stimulus and signals originated from the environment [1]. In terms of categorization, physical sensors and chemical sensors are the two most fundamental and widely opted classes of sensors. Te main idea behind this frst classifcation also arises from scrutinizing the human senses. Since the common working mechanism behind the sense of hearing, touch and sight is to respond on the external physical stimuli (i.e., acoustic waves, pressure and electromagnetic radiations respectively), hence any sensing device that provide response to the physical property of the medium was termed as physical sensor [2]. Similarly, the senses of taste and smell respond to chemical stimuli of odor and particular palate favor of the molecules; any sensing device that can transform chemical information of the system into analytically analyzable signals was included into the division of chemical sensors [3]. Te comprehensive pictorial description of the customary sensor is given in Figure 1. Sensor contains specifc reacting site that could respond to a specifc sort of an analyte in the medium. Analyte/ stimulus triggers a chemical interaction at the site which initiates the conversion of information into electrical signal. Electrical signal is then transmitted to another unit, the processing unit that further carries out the detection response [4]. Technically, the sensor is composed of two parts i.e., receptor and transducer. Receptor receives the physical/ chemical stimulus and transmutes this information in the form of electrical energy while transducer performs the function of transducing this energy into valuable analytical signal which can further be analyzed and presented in an electronic form [5] (Figure 1). Numerous other classes including magnetic sensors [6-8], Biosensors: Their Fundamentals, Designs, Types and Most Recent Impactful Applications: A Review Jazib Ali 1 *, Jawayria Najeeb 2 , Muhammad Asim Ali 1 , Muhammad Farhan Aslam 1 and Ali Raza 1 1 National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan 2 Institute of Chemistry, University of the Punjab, Lahore (PU), Pakistan Abstract Biosensors are the devices that capture the biological signal and convert it into a detectable electrical signal. It involves the combination of biological entities like DNA, RNA, and proteins/enzymes to the electrochemical transducers in order to detect and observe certain biological analytes like antibody-antigen interaction. Several types of biosensors have been known that have been successfully employed in the felds of environment, biomedical and food industries to detect and remove certain contaminants, weather non-living or living entities. Amperometric, Optical, Surface Plasmon Resonance, enzymatic, DNA, Phage, and bacterial sensors are the common sensors being employed today. These biosensors can be used for the detection of the broad spectrum of biological analytes and have shown greater responses and success in medical laboratories, food bioanalysis, microbial detection etc. Detection of the lower or higher limits of glucose in body, microbial invasion in body and food, heavy metals detection in soil, water and air-borne microbes, pesticides in water and soil and various harmful chemicals produced by body, can be easily and timely monitored with high precision using the different types of biosensors with few modifcations. SENSOR TRANDUCER 3) 1) 2) Figure 1: Diagram representing various processes occurring in sensors 1) analyte is getting attracted to the receptor sites 2) chemical interaction between analyte generating electrical signal 3) Transducer transducing the electrical signal to processor.