Electrochemical determination of progesterone in calf serum samples using a molecularly imprinted polymer sensor

A simple sensor for the determination of progesterone (P4) was developed using a molecularly imprinted polymer as a recognition element. Towards this goal, gold nanoparticles were first electrochemically generated on glassy carbon electrodes to improve the overall activity of the surface. Then, the imprinted polymer was deposited via electropolymerization of aminophenol in the presence of the target analyte. The resulting sensor presented good analytical characteristics for the determination of P4 with a linear response ranging from 0.2 to 125 nmol L-1 with a limit of detection and quantification of 0.17 and 0.35 nmol L-1, respectively. The sensor's selectivity was studied with compounds with a similar structure to P4 and no interference effects were observed. The sensor showed an adequate response, even 30 days after its preparation, and allowed performing at least 12 consecutive determinations, maintaining a good response. The proposed sensor offers a simple alternative to these analyses, with fast production, and competitive performance. While the capabilities of the sensor to target real samples were demonstrated via the quantification of P4 in calf serum samples, the selected strategy (using gold nanoparticles as catalytic centers for the synthesis of the molecularly imprinted polymer) could be widely applied to the development of other sensors for non-electrochemically active analytes.