A comprehensive review on graphitic carbon nitride based electrochemical and biosensors for environmental and healthcare applications

Graphitic carbon nitride (g-C3N4) belongs to an older age class of 2-D semiconducting materials that are affordable, metal-free, indispensable towards sensing applications due to identifiable changes in their conductivity after analyte exposure especially when they are in the nano-regime. More than 400 reviews on g-C3N4 have been highlighted its wide exploration as photocatalyst on energy conversion devices, hydrogen evolution, photoelectrochemical studies. A part of about 20 reviews also explained the photoluminescence based optical, fluorescence, and colorimetric sensors. But, none of these reviews elaborated on the emerging dimensions of g-C3N4 based electrochemical sensors and their future concerns towards disposable electrodes for healthcare applications. Hence, the principal focus of this review summarizes the analytical parameters; various methods existed for the preparation of pyrolytically processed g-C3N4 based nanocomposite/hybrid materials. Furthermore, the mechanistic features of g-C3N4 modified electrochemical sensors towards the environmental and healthcare applications such as detection of toxic metals, inorganic anions, nitroaromatic compounds, phenolic compounds, antibiotics, simple organic molecules, neurotransmitters, and foodborne pathogens were discussed in detail. Undoubtedly, this review would give future insights for the researchers working on the electrochemical sensor field to explore the fascinating g-C3N4 material as a sensing platform that is at par with several other electrode modifications reported in the literature. This survey could unveil some interesting electrochemical aspects of g-C3N4 that can aid in analyzing its interaction with other environmental pollutants and biomolecules required in health care needs.