Electro-responsive\nMolecularly Imprinted Polymers\n(E-MIPs) for Rapid Detection of Progesterone in Human Serum Samples

Rapid\nand reagent-free detection of progesterone (P4) is crucial\nin point-of-care (POC) measurement due to its important role in the\nhuman endocrine and central nervous system. Currently available technologies\nfor P4 detection are often not rapid or require reagents, limiting\ntheir use in POC settings. In this work, a self-signaling electrochemical\nsensing platform for rapid detection of P4 is developed by using electroactive\nmolecularly imprinted polymers (E-MIPs). E-MIPs possess the ability\nto transduce the molecular recognition event into a measurable electrochemical\nsignal. The E-MIPs are prepared by bulk copolymerization of acrylic\nacid (AA) and ferrocenylmethyl methacrylate (FcMA) in the presence\nof P4 followed by its removal from the polymer matrix. By incorporation\nof ferrocene moieties, the MIP gains intrinsic electroactivity, enabling\nlabel-free and direct electrochemical detection of P4 levels. Electrochemical\ntechniques, including cyclic voltammetry and electrochemical impedance\nspectroscopy, were employed to elucidate the electron transport reaction\nresponsible for the MIP’s intrinsic electroactivity. Additionally,\nthe predetermined complementary binding sites confined to the small\nworking area of the screen-printed carbon electrode (SPCE) within\nthe E-MIP matrix facilitate rapid P4 binding, achieving completion\nwithin 120 s. The developed E-MIP sensing platform was used for the\nrapid detection of P4 levels in human serum samples. The short incubation\ntimes reported for the E-MIP sensing platform would be beneficial\nin minimizing the nonspecific binding in the real-world samples. We\nbelieve that the proposed E-MIP sensing platform can be applied to\nclinical samples for detecting fluctuations in P4 levels.