3.1.2.2. Chitosan-Based Electrochemical Nucleic Acid Biosensors:
Chitosan-based DNA biosensors are formulated by surface fixing of biotinylated probe DNA by its anionic phosphate to cationic amino group of chitosan either by covalent bonding or affinity conjugation. This sensor was used to detect Gonorrhea (a sexually transmitted illness), as reported by Singh et al, (2011). Another application of chitosan-based nucleic acid biosensor was used for detecting Salmonella typhi by immobilizing ss DNA of infectious agent on graphene oxide/chitosan/ITO nanocomposite (Singh et al., 2013). Complementary, noncomplementary, and one base mismatch sequences may all be distinguished by the biosensor. For the detection of E. coli 0157:H7, a comparable electrochemical DNA biosensor was created by immobilizing SS E. coli DNA using a graphene oxide chitosan hybrid nanocomposite (Xu et al., 2017).