CMOS potentiostat and sensor with multilayer membrane for wide range measurements of glucose concentrations

We report on an electrochemical measurement setup comprising a CMOS potentiostat and a glucose sensor with a two-layer membrane as the first steps towards the development of an integrated in-situ sensor system for bioreactors. The potentiostat has a chip size of 2.1 x 2.5 mm2 and a linear current range from -220 nA to 240 nA with a linearity of R2 = 0.9995. For wide range measurements of glucose concentrations in cell culture media, electrodes functionalized with the enzyme glucose oxidase were spin-coated with membranes made from polydimethylsiloxane (PDMS). With these membranes, glucose concentrations up to 400 mM were measured with a linear measurement range up to 100 mM. For interferent elimination, cellulose acetate membranes were employed.