MoS₂ Nanoflower-Molecularly Imprinted Polymer-Based Electrochemical Sensor for Trace Level Determination of Tau-441 Protein

Alzheimer's disease (AD) represents a growing medical and societal challenge in the 21st century due to its rising global prevalence. Early diagnosis using reliable biomarkers, such as Tau-441, is crucial for effective disease management. Nevertheless, current detection systems often suffer from high costs, inadequate sensitivity, and the need for specialized staff. Molecularly imprinted polymers (MIPs) offer a promising alternative due to their biomimetic recognition capabilities, cost-effectiveness, and ease of fabrication. In this study, a structurally designed MIP-based electrochemical sensor was developed for the rapid, sensitive, and selective detection of Tau-441. Silver nanoparticles were electrodeposited onto a glassy carbon electrode, followed by the coating of 3D molybdenum disulfide nanoflowers synthesized via a solvothermal method. The electropolymerization of dopamine formed the MIP layer in the presence of Tau-441. The nanosensor demonstrated a broad linear detection range (1.93 fM to 100 pM) and a low detection limit of 0.59 fM. As a proof-of-concept, the prepared sensor was successfully applied to human serum and artificial cerebrospinal fluid samples, demonstrating excellent recovery and selectivity. The sensor achieved recoveries of 91.41-109.4% with RSD values below 5%, confirming its analytical reliability under real-sample conditions. The MIP nanosensor maintained 68.47% of its initial response after 12 days and also demonstrated outstanding repeatability (0.32% RSD). The proposed nanosensor holds significant potential for integration into clinical diagnostic kits aimed at the early detection of AD.