In situ electrochemical synthesis of graphene-poly(arginine) composite for p-nitrophenol monitoring

Para-Nitrophenol (p-nitrophenol) is a common industrial pollutant occurring widely in water bodies, yet actual monitoring methods are limited. Herein we proposed a fully electrochemically in situ synthesized graphenepolyarginine composite functionalized screen printed electrode, as a novel p-nitrophenol sensing platform. The electrode was characterized by morphologic, spectrometric and electrochemical techniques. p-nitrophenol in both pure aqueous solution and real water samples was tested. Results show a detection limit as low as the nanomolar level, and display a linear response and high selectivity in the range of 0.5-1250 mu M. Molecular simulation reveals a detailed synergy between graphene and poly-arginine. The preferable orientation of nitrophenol molecules on the graphene interface in the presence of poly-arginine induces H- and ionic binding. This sensor is an ideal prototype for p-nitrophenol quantification in real waters.

Automated summary

A novel p-nitrophenol sensing platform utilizing a graphene-polyarginine composite functionalized screen printed electrode was proposed in this study. The sensor showed a low detection limit and linear response for p-nitrophenol in both pure aqueous solution and real water samples, making it an ideal prototype for quantification of p-nitrophenol in real waters. Synergy between graphene and poly-arginine was revealed through molecular simulation, highlighting the importance of their interaction in the sensing mechanism.