Preparation and application of electrochemical barbital sensor based on molecularly imprinting technique

A molecularly imprinted electrochemical sensor was prepared based on poly folic acid (PFA) for rapid detection of barbital (BAR). The PFA membrane was obtained via directly electropolymerization technique on the surface of chemically modified Au electrode (Au/CME) by means of cyclic voltammetry (CV) in the potential range between -0.4 and 1.0 V in phosphate buffer solution (PBS) pH 7.04. The molecularly imprinted polymers (MIP) membrane was synthesized with BAR as template molecules and folic acid (FA) as the functional monomer. The performance and surface feature of the proposed imprinted sensor were investigated using CV, differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). Under the optimized conditions, the peak current decrease (ΔI _p) was proportional to the BAR concentration in the range of 1.00×10^–7-1.00×10^–4 mol/L (R ²=0.998 2) with a detection limit (S/N=3) of 4.65×10^–8 mol/L. The results indicated that the imprinted sensor exhibited an excellent selectivity for BAR and it was successfully used to determine BAR in real samples with recoveries of 94.7%-106.2% by using the standard addition method.