Microwave-Assisted Incorporation and Optimization of Mn Doping in MoS₂/RGO for Electrochemical Sensing of Uric Acid: Transition from Multi-Detection to Single-Detection

A novel electrochemical biosensor based on manganese-doped molybdenum disulfide/reduced graphene oxide (Mn-MRG) for the selective determination of uric acid (UA) in the presence of interfering species such as ascorbic acid (AA) is presented. Mn-MRG composite utilizes the synergistic properties of Mn, MoS 2 , and RGO for enhanced electrochemical performance. Structural and morphological characterizations confirm successful incorporation of Mn into the MoS 2 /RGO matrix. Mn-doped MoS 2 /RGO offers extremely low detection limits of 80 nM for UA with high sensitivity of 258 nA·μM −1 cm −2 , and a wide linear response within the range of 30 μM up to 1.1 mM. After doping with 9% manganese, this sensor detected only UA and eliminated interference from AA, mainly because Mn doping provides specific interactions and enhances electron transfer kinetics. Mn acts as both the oxidizing agent for UA and as a reducing agent for AA, which is central to its performance. This work demonstrates enhanced selectivity and sensitivity through strategic Mn doping, which modulates electron transfer kinetics and redox interactions. This bidirectional redox activity removes interference with AA, providing a highly selective nature. Excellent sensitivity, selectivity, and practicability make the Mn-MRG biosensor a promising candidate for the precise detection of UA in biomedical and clinical applications.