Screen printed carbon electrode modified with poly(L-lactide) stabilized gold nanoparticles for sensitive As(III) detection

Poly(L-lactide) stabilized gold nanoparticles (designated as PLA-Au-NP) with an average particle size of ca. 10 nm were used to modify a disposable screen-printed carbon electrode (SPE) for the detection of As(III) by differential pulse anodic stripping voltammetry. Gold modification was evaluated by cyclic voltammetry, whereas scanning electron microscopy and transmission electron microscopy revealed the size and distribution of gold nanoparticles. The PLA-Au-NP/SPE was applied effectively to detect toxic As(III) in HCl medium. Under the optimal experimental conditions, a linear calibration curve up to 4 ppm with a detection limit (S/N= 3) of 0.09 ppb was obtained. ne sensitivity was good enough to detect As(III) at levels lower than the current EPA standard (10ppb). Most importantly, the PLA-AU(NP)/SPE can be tolerable from the interference of Cu, Cd, Fe, Zn, Mn, and Ni and hence provides a direct and selective detection method for As(III) in natural waters. Practical utility of the PLA-AU(NP)/SPE was demonstrated to detect As(III) in "Blackfoot" disease endemic village groundwater from southwestern coast area of Taiwan (Pei-Men).