Electrochemical stripping detection of cadmium with paper-based channels for point-of-care detection

Abstract

This paper describes the development of a heavy metal sensor with point-of-care detection for heavy metal detection based on paper channel. A heavy metal detection sensor using a three-electrode system was fabricated on the surface of PET by screen printing. The working electrode is made of carbon paste containing antimony precursors, the reference electrode is made of Ag/AgCl paste, and the auxiliary electrode is made of carbon paste. The fabricated three electrodes were designed to deliver target substance through a paper-based channel to allow very easy point-of-care detection. When measuring cadmium, the fabricated three electrodes showed the highest sensitivity when the antimony precursor concentration was 5 wt/wt%, which was about 2.18 times higher than that of the carbon paste electrode. The fabricated heavy metal sensor had a cadmium detection range of 20–2000 μg/L and a linear coefficient (R2) of 0.988 in the detection range of 20–500 μg/L. The developed paper channel-based heavy metal sensor can be fabricated at a very low cost and is expected to be applicable to other heavy metal detection applications.