Polydopamine Molecularly Imprinted Reduced Graphene Oxide‐MoS ₂ Nanocomposite Electrodes for Electrochemical Detection of Cortisol and Estradiol

Polydopamine (PDA)‐based molecularly imprinted polymers (MIPs) integrated with two‐dimensional layered materials (2DLMs) were developed as selective recognition platforms for the electrochemical detection of the cortisol and estradiol hormones. Graphene oxide (GO), reduced graphene oxide (RGO), and RGO‐molybdenum disulfide (MoS 2 ) nanocomposites were synthesized through solution‐based methods and characterized using morphological, spectral, elemental, and electrochemical techniques. The nanomaterials were deposited onto screen‐printed carbon electrodes (SPCEs) to fabricate nanomaterial‐modified electrodes, followed by the electropolymerization of dopamine in the presence of hormone templates to generate PDA‐based molecularly imprinted sensing interfaces. The resulting imprinted electrodes were employed for the electrochemical sensing using electrochemical impedance spectroscopy (EIS) as the signal transduction method. The MIP‐modified RGO‐MoS 2 /SPCE exhibited enhanced sensitivity owing to the high conductivity and large surface area of the nanohybrid support. Under optimized conditions, the sensor demonstrated a linear detection range of 0.5 nM–10 µM with a detection limit of 0.1 nM for estradiol and a linear range of 100 pM–5 µM with a detection limit of 10 pM for cortisol. The improved sensing performance is attributed to the synergetic combination of PDA‐based molecular imprinting for selective recognition and conductive 2D nanomaterials for efficient electron transfer. This study demonstrates the potential of PDA‐imprinted 2D nanomaterial interfaces for developing low‐cost, sensitive, and portable electrochemical sensors for hormone detection in biological fluids.