A novel ZrO2@PVA-PPy nanocomposite based electrochemical sensor for detection of anti Covid-19 drug Favipiravir in formulation, human plasma and various wastewater samples

ZrO2@PVA-PPy nanocomposite was synthesized and characterized. ZrO2@PVA-PPy/CPE was designed as a sensor for detection of FVR in different real samples and its electrochemical reduction was also fully studied. SW-AdCSV method is markedly detected the quasi-reversible reduction of its enol and keto forms and proves that FAR is present in an acid-base equilibrium of pKa equals 7. This nanocomposite considers being a potential candidate for the FVR selection and trace detection in different matrices including pharmaceutical formulation, human plasma and wastewaters. [Display omitted] •ZrO2 NRs were first prepared.•ZrO2@PVA-PPy nanocomposite was then prepared.•ZrO2@PVA-PPy based sensor was successfully detected anti Covid-19 drug Favipiravir drug.•LOD of 8.10 × 10-12 M was achieved.•This sensor was applied in various real samples. A novel ZrO2 doped polymeric nanocomposite based on ZrO2 nanorods and conducting polymers of polyvinyl alcohol and polypyrrole (ZrO2@PVA-PPy) was synthesized and characterized using several techniques. The XRD pattern of ZrO2 indicates its high crystallinity and the presence of tetragonal and monoclinic phases while for ZrO2@PVA-PPy composite; the peaks of ZrO2 NRs almost disappeared confirming their covering by a thick layer of mixed PVA-PPy. EDX spectrum of the nanocomposite showed intense peaks for Zr, C, O, and N elements. TEM images of ZrO2 indicate the free-standing rod-like nanostructures (with average length and width of 200 and 83.7 nm, respectively) coated well with a PVA-PPy layer. ZrO2@PVA-PPy/CPE was designed as a smart chemosensor for Favipiravir (FVR) drug detection in different matrices. ZrO2@PVA-PPy/CPE exhibited a larger electroactive surface area (0.60 cm2) and lower charge transfer resistance (1.50 KΩ) compared to 0.25 cm2 and 8.00 KΩ for bare CPE. The utility of ZrO2@PVA-PPy sensor for bulk FVR detection are superior over those of all the reported voltammetric sensors relying on its wide linear range(4.00 × 10−11 − 5.00 × 10−8 M) and very low LOD value (8.10 × 10−12 M). It was also used for determination of FVR in real complexed samples including the brand and local “Avigan®” and “Epifluvir” tablets, respectively, human plasma and various wastewater samples. A very low LOD (1.96 × 10−10 M) was achieved in human plasma. ZrO2@PVA-PPy/CPE is the most suitable sensor for therapeutic FVR drug monitoring purposes and for its subsequent employing in analytical studies of various medical and environmental samples.