A Novel Sensitive Electrochemical Sensor for Podophyllotoxin Assay Based on the Molecularly Imprinted Poly-o-Phenylenediamine Film

An electrochemical sensor for podophyllotoxin (PPT) based on the molecular imprinting polymer (MIP) membranes was constructed. The sensor was prepared by electropolymerizing ophenylenediamine (o-PD) on a glassy carbon electrode (GCE) in the presence of PPT as template, and then removing the template by immersing the modified GCE in ethanol. Experimental parameters such as the types of monomer, scan cycles, concentration of o-PD and extraction condition were optimized. Under optimal conditions, the sensor exhibits a good selectivity and high sensitivity. A good linearity was obtained in the range of 4×10⁻⁸ mol · L⁻¹ to 3.2×10⁻⁵ mol · L⁻¹ with an estimated detection limit of 4.8×10⁻⁹ mol · L⁻¹. The sensor was applied to the determination of PPT in podophyllum hexandrum and human serum samples with satisfactory results.