In-situ Self-polymerization PDA@MXene/MB Ratio Electrochemical Sensing for the Detection of Kaempferol

Kaempferol (KA) is an important natural flavonoid compound, and its sensitive detection is of great significance in food science and pharmacological analysis. To address the problems of traditional electrochemical sensors being susceptible to environmental interference and having poor stability in complex samples, this study successfully prepared a polydopamine-modified MXene/methylene blue composite material (PDA@MXene/MB), and constructed a novel ratio electrochemical sensor for the highly selective and sensitive detection of kaempferol. This sensor utilizes the high conductivity and large specific surface area of MXene as an ideal base, and through the in-situ polymerization of polydopamine, effectively prevents the stacking of MXene layers and simultaneously fixes methylene blue (MB) as a stable and reliable internal reference signal. During the detection process, the ratio of I KA /I MB is used for quantitative analysis, effectively eliminating the interference of background current fluctuations and environmental factors. Experimental results show that this sensor exhibits excellent analytical performance for kaempferol, presenting a good linear relationship within the concentration range of 0.4-36   µM, with a detection limit of 49   nM. Moreover, the sensor demonstrates good selectivity, reproducibility and stability, and it was also successfully used to determine kaempferol in actual tablet sample, yielding satisfactory recovery rates.