Carbon nanomaterials for salivary-based biosensors: a review

In recent years, saliva has been introduced as an alternate to conventional biofluid assays owing to both accessibility and reliability with regard to the assessment of different biomarkers. The capability of immediate online collection and analysis of salivary biomarkers offers myriad benefits for clinical applications, resulting in the demands for quantifying salivary biomarkers rapidly and reliably with the help of biosensing technology. Carbon–nanomaterial based biosensors provide potential instruments for a non-aggressive pain-free style of saliva-dependent recognition to diagnoses, monitor, and formulate a therapeutic modality and for managing patients. This review covers the importance of carbon nanomaterial in fabricating salivary-based detectors applied clinically for diagnostics and therapeutics. The utilization of carbon nanomaterials comprising carbon dots (CDs), carbon nanotubes (CNTs), graphene, graphene oxide (GO), reduced graphene oxide (rGO) and graphitic carbon nitride (g-C₃N₄) in salivary-based detection has been highlighted here with up-to-date instances. These sensing systems are capable of detecting a vast range of molecules with clinical relevance, including glucose, hormones, amino acids, viruses, bacteria, cancer antigens, cancer biomarkers, dopamine, sialic acid, uric acid, etc. which were discussed in this paper.