A novel Au-Ag-Pt three-electrode microchip sensing platform for chromium(VI) determination.

A simple, rapid and portable electrochemical microchip sensing platform has been successfully constructed for chromium(VI) determination. Gold-silver-platinum (Au-Ag-Pt) three-material electrodes (gold as working electrode, silver as reference electrode and platinum as counter electrode) were integrated on one poly(methyl methacrylate) (PMMA) substrate by polymer compatible photolithography process. The three-electrode microchip sensing platform was used for Cr(VI) determination for the first time, and exhibited high sensitivity and good reproducibility. A wide linear range from 2 to 200 μM with a good linear correlation (R(2)=0.998) was obtained, and the detection limit was 0.9 μM. In addition, the practical analytical application of the sensing micro-platform was assessed by determination of Cr(VI) in real water samples with satisfactory results. Armed with the remarkable advantages, such as ease of use, low analyte consumption, inexpensive cost and fast response time, the microchip sensing platform may hold great potential for the high-throughput and in-field environmental monitoring Cr(VI) pollutant.