Nanocarbon induced graphene platelet suspension for generation of dopant free filter paper based electrochemical biosensor

The chemical dissimilarity of nanoparticle dopants with surface coating materials has been found to tune the electrical and surface properties of carbon coated paper-based biosensing devices majorly due to surface inhomogeneity and reduced sensitivity. Herein we present a dopant free carbon nanomaterial suspension to improve the electrical properties of a smartly fabricated model paper-based biosensing platform. The nanocarbon induced graphene platelet suspension (NanoGPS), was found to have better aqueous suspendability and homogeneity to achieve enhanced electrical properties. NanoGPS has been thoroughly characterized using various physio-chemical methods to confirm the introduction of nanocarbon in exfoliated graphene nanoplatelets (GNP). To probe the improvised efficiency of optimized dopant free NanoGPS, it was utilized to fabricate a model system of electrically active paper device (Elecro-PAD) and used for the non-invasive detection of lactate dehydrogenase (LDH) in simulated saliva for plausible oral cancer diagnosis. The Electro-PAD was tested in different complex matrices and showed a limit of detection (LoD) and limit of quantification of ~2.0 nM and ~ 6 nM, respectively. The device has been also benchmarked against gold standard conventional method and the results were found to be comparable to that of ELISA with recovery percentage of more than 90 % at different clinically relevant concentrations. Thus, the strategy of generating dopant free Nano-GPS has been found to be an effective approach for the improvement of electrical properties while avoiding the use of conventional dopants. • Graphene nanoplatelet exfoliation by nanocarbon (NanoGPS) to improve electrical properties. • NanoGPS avoids conventional dopants to tune electrical properties. • NanoGPS have been effectively used to fabricate Electro-PaD biosensing platform. • NanoGPS provides functional groups for the conjugation of biorecognition units. • Electro-PaD has been used to detect LDH levels in saliva for oral cancer diagnosis.