A portable potentiostat for the bilirubin-specific sensor prepared from molecular imprinting

A portable amperometric potentiostat was designed and implemented in this work. It was developed to acquisit the current signals produced from bilirubin by an electrochemical sensor. Based on an SOC-based chip, this potentiostat has the merits of moderate accuracy, small size, low cost, and high portability. The bilirubin electrode was prepared by synthesizing a thin layer of bilirubin imprinted poly(methacrylic acid-co-ethylene glycol dimethacrylate) onto the Au layer. With the molecularly imprinted polymer (MIP) film, specific detection of bilirubin was successfully achieved. The cyclic voltammogram of the electrode was measured from this assembled potentiostat. The performance from a commercial potentiostat was considered rather stable and was used as a reference to examine and evaluate the performance of the assembled potentiostat. The detected current signals by the bilirubin sensing were obtained. Linear calibration with a sensitivity of 1.344 ± 0.38 μA/mg dl was achieved. Our experimental results showed that the proposed potentiostat's performance could achieve sufficient performance. The evaluation was also made from the aspects such as reset time and steady-response time. The self-assembled potentiostat thus demonstrated its ability in precise detection of bilirubin from an electrode layered with the imprinted polymer film.