Electrochemical creatinine sensor based on a glassy carbon electrode modified with a molecularly imprinted polymer and a Ni@polyaniline nanocomposite

The article describes an electrochemical creatinine sensor that is based on a glassy carbon electrode (GCE) modified with a magnetic molecularly imprinted polymer (MMIP) and a composite consisting of nickel nanoparticles and polyaniline that was prepared by electropolymerization. Aniline and methacrylic acid were used as the bifunctional monomers, and creatinine was used as the template molecule. Electrochemical deposition was performed via cyclic voltammetry in the potential range from -0.3 V to 1.2 V and at a scan rate of 50 mV center dot s(-1) over 20 cycles. The Ni@PANI NPs were characterized by scanning electron microscopy, FTIR, X-ray diffraction and thermogravimetric analysis. The Ni@PANI-modified GCE was characterized by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. Under optimized conditions, the sensor displays a linear response to creatinine in the 40 to 800 nM concentration range, with a 0.2 nM detection limit. The method was successfully applied to the detection of creatinine in urine mimic and in spiked urine samples.