Electrochemical genosensors: definition and fields of application

The conventional methods used for specific sequences detection in nucleic acids based on DNA sequence polymerization (PCR) or DNA hybridization (FISH), present certain drawbacks such as the requirement of expensive equipment, time-consuming, laborious and in some case a low sensitivity. Therefore, biosensors are the most attractive alternative providing simple, reliable, fast and selective detection systems. An electrochemical biosensor is an analytical tool composed of bioreceptor that specifically recognizes a biological agent of interest (analyte), which results in a (bio) chemical signal converted by the transducer into an exploitable signal [1]. Development and use of electrochemical genosensors are evolving at a rapid pace, the definition of the electrochemical genosensors and their classification can not unequivocally answer all details and nuances. Biosensors classification may be made according to the biological specificity conferring mechanism or to the mode of signal transduction or, alternatively, a combination of the two [1], for detailed definition and classification, I invite you to read the paper of Thévenot et al. [1] & Ozsos’s book [2]. In electrochemical genosensors, the bioreceptor can be a probe (small sequence of oligonucleotides, in case of electrochemical DNA-based genosensor) or an aptamer (synthetic oligonucleotides sequence, in case of electrochemical Aptamer-based genosensor) immobilized at the transducer surface, due to their affinity, these oligonucleotides sequences recognize the analyte (Nucleic acids) by complementarity making duplexes. The electrochemical DNA-based genosensors can be coupled with nanoparticles or nanocomposites to improve both oligonucleotides sequence immobilization on the transducer surface and sensitivity to hybridization [3-7]. The electrochemical techniques applied in genosensor can be used in different goals, e.g Differential Pulse Voltammetry (DPV) as analystical technique is usually used to measure the concentration of some specific electroactive species with high sensitivity [8]. This paper is devoted to giving a general idea about the fields of application of electrochemistry, such as medicine, plant breeding, food safety and quality control, and bacterial and viral analysis.