Core–shell nanocomposite of flower-like molybdenum disulfide nanospheres and molecularly imprinted polymers for electrochemical detection of anti COVID-19 drug favipiravir in biological samples

A novel electrochemical sensor is reported for the detection of the antiviral drug favipiravir based on the core–shell nanocomposite of flower-like molybdenum disulfide (MoS 2 ) nanospheres and molecularly imprinted polymers (MIPs). The MoS 2 @MIP core–shell nanocomposite was prepared via the electrodeposition of a MIP layer on the MoS 2 modified electrode, using o-phenylenediamine as the monomer and favipiravir as the template. The selective binding of target favipiravir at the MoS 2 @MIP core–shell nanocomposite produced a redox signal in a concentration dependent manner, which was used for the quantitative analysis. The preparation process of the MoS 2 @MIP core–shell nanocomposite was optimized. Under the optimal conditions, the sensor exhibited a wide linear response range of 0.01 ~ 100 nM (1.57*10 −6  ~ 1.57*10 −2  μg mL −1 ) and a low detection limit of 0.002 nM (3.14*10 −7  μg mL −1 ). Application of the sensor was demonstrated by detecting favipiravir in a minimum amount of 10 μL biological samples (urine and plasma). Satisfied results in the recovery tests indicated a high potential of favipiravir monitoring in infectious COVID-19 samples. Graphical abstract