A low-cost hybrid GQDs/Fe3O4/polypyrrole nanocomposite based chemo-sensor for electrochemical non-enzymatic selective determination of creatinine in biological samples

A novel electrochemical non-enzymatic chemo-sensor based on low-cost hybrid graphene quantum dots/iron oxide/polypyrrole nanocomposite (GQDs/Fe3O4/Ppy NC) was synthesised by solvothermal method to determine the creatinine (CTN). The physicochemical properties of prepared nanocomposite have been studied by XRD, XPS, FTIR spectroscopy, UV-visible spectroscopy, FE-SEM, EDX and HRTEM analysis. Herein, glassy carbon electrode (GCE) was modified with GQDs/Fe3O4/Ppy NC and the voltametric sensing behaviour of CTN was analysed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The synergetic coupling effect of Fe3O4 nanoparticles with GQDs and Ppy in nanocomposites may provide an excellent catalytic activity towards CTN sensing, which exhibits a good wide linear range (0.1 to 100 mu M) with the lowest detection limits (0.009 mu M). Moreover, it is a good sensor platform with high selectivity towards CTN in the existence of significant interference such as ascorbic acid, dopamine, uric acid, urea, L-cysteine, glucose and heavy inorganic metals like cadmium and lead. Additionally, it displays better repeatability, reproducibility and sensitivity. Besides, Real-time feasibility of the developed sensor device was successfully utilized for the determination of CTN being proved in actual human blood serum and urine samples with and without the addition of commercial synthetic samples.