Electron Transport of Zigzag Graphene Nanoribbon Based Biosensor-A Future Perspective towards Biosensor and Biomedical Applications

Graphene, the profound mother of carbon nanostructures has attracted tremendous attention towards biosensor and biomedical research through its enhanced property of sensitivity and specificity. In the present study, we explore the biological applications of zigzag graphene nanoribbon (ZGNR) as molecularscale biosensors by calculating the electronic properties of zigzag graphene nanoribbon (ZGNR) and paracetamol drug ensemble. Here the drug is adsorbed at the edge of ZGNR through physisorption. The non-covalent interaction between ZGNR and the drug is studied by calculating the transmission spectrum and density of states using non-equilibrium Green's function formalism (NEGF) and density functional theory(DFT).We have simulated different systems like bare ZGNR, hybrid system consisting of ZGNR and paracetamol, hybrid system with central doping of nitrogen, hybrid system with edge doping of nitrogen, hybrid system consisting of nitrogen replacing one complete edge layer carbon atoms and their corresponding I-V characteristics and transmission spectrum are reported. Our results show a significant suppression of transmission spectrum supported by the variation in density of states (DOS) thereby showing a distinct response to the molecule for sensing action. Further, bare ZGNR system is chosen as the reference. The decrease in the I-V characteristics of all the chemically modified systems clearly indicates tuning of band gap thus proving the sensing effect of ZGNR for biomedical applications.