Surface Engineering of Carbon Nanotubes via Heteroatom Doping for Electrochemical Detection of Diphenylamine

To design and develop a facile synthesis of hollow tubular carbon-based materials with higher catalytic performances remains challenging. Herein, a self-sacrificing template strategy is employed for the construction of graphitic layer wrapped carbon nanotubes (CNTs) encapsulated with nitrogen and sulfur heteroatoms. Surface engineering of nitrogen and sulfur codoped porous carbon nanotubes (NSCNTs) is described. A synergistic effect of heteroatom doping and porosity tuning upon the electrochemical performance is demonstrated for the effective detection of diphenylamine (DPA). Differential pulse voltammetry was employed as an electrochemical tool to assay DPA using NSCNT-0.5/GCE with increased sensitivity compared with an unmodified electrode. Benefiting from abundant catalytic active sites and faster electron transfer kinetics, the NSCNT altered electrode covered a wide range of concentrations (5–500 μM) and achieved a LOD of 0.019 μM with appreciable sensitivity. Moreover, the negligible effect over potential interferents, reproducibility measurements, and operational stability had augmented much effect on DPA sensing, which makes it an ideal sensing device feasible for electrochemical analysis. Real sample analysis scrutinized the excellent efficiency and reliability of the proposed sensor with fruit samples for the detection of DPA with peerless recovery range. The strategy developed herein reveals a feasible path for enhancing the electrochemical applications.