Nanoporous gold microelectrode for electrochemical sensing of As(III) in cellular environment

The highly toxic arsenite (As(III)) could cause serious cytotoxicity on metabolism, resulting in several diseases. However, it is still a great challenge on the precise sensing of As(III) in complicated conditions, especially in cellular environment. In this work, a nanoporous gold microelectrode (NPG-μE) was fabricated by a simple electrochemical alloying/dealloying method and developed for the electroanalysis of As(III) in the lung cancer cellular (A549 cells) environment. The as-fabricated NPG-μE exhibited the excellent electrochemical performance towards As(III) detection at physiological pH (0.1 M PBS solution, pH 7.4) with a high sensitivity of 5.07 μA ppb-1 cm-2 and a low limit of detection of 0.25 ppb (S/N = 3). The large surface area derived from the nanoporous structure, and the well-dispersed active sites as well as the highly electro-catalytic activity of gold played a critical role on the improved electrochemical behaviors. Furthermore, the effect of the exposure time on electrochemical monitoring As(III) in A549 cellular environment was successfully investigated, revealing the fatal impact of As(III) on cell cycle. This work offered a great trial on investigating of the cytotoxicity of arsenite and their precise detection in complicated cellular environment.