A low-cost potentiostat for point-of-need diagnostics

The work presented details the development of a low-cost potentiostat, with the aim of creating an ink-jet printed hybrid paper-based low-cost sensing system for rapid water quality monitoring. Potentiostats exhibit high sensitivities and can be used for a variety of applications. In this application, they use electrochemical techniques to detect heavy metals via stripping analysis. The potentiostat front-end, consisting of an LMP91000 sensing chip, was designed and manufactured on a printed circuit board (PCB) and compared to a laboratory-based potentiostat using cyclic voltammetry performed using an 80 ßl sample of 5 mM ferri-ferrocyanide dropped onto a commercial screen-printed electrode. The results obtained from the PCB potentiostat are comparable to those obtained using the development board and the laboratory-based potentiostat. The results highlight the functionality of a low-cost point-of-need potentiostat that can be used for environmental monitoring as well as the feasibility of transferring the design to a paper substrate.