l-Cysteine modified flexible PDMS–gold electrode for sensing ascorbic acid and copper

Applications of flexible poly(dimethylsioxane) (PDMS)-based gold electrode were expanded, modification of l-cysteine on the electrode was carried out, and applied for sensing ascorbic acid and copper. Electrochemical properties of proposed modified electrode were similar to that of conventional electrode. Copper(II) was accumulated on the l-cysteine modified electrode and measured with cyclic voltammetry, reductive currents were linear with concentrations of copper(II) in range of 10−8 to 1.5 × 10−6 M and limit of detection was 5.0 × 10−9 M. This proposed sensor could give quick response to ascorbic acid (AA) (<5 s) and the currents were linear with concentrations of AA in range of 6.6 × 10−7 to 2.6 × 10−3 M and limit of detection was 2 × 10−7 M. The performance was better than previous reports. The devices are simple, low-cost, easy-to-fabricate and portable. Therefore, conventional modification methods could be applied on the flexible poly(dimethylsioxane) (PDMS)-based gold electrode for point-of-care applications in environmental monitoring, public health, and food safety.