Electrochemical sensor based on molecularly imprinted membranes at platinum nanoparticles-modified electrode for determination of 17β-estradiol

In this paper, an electrochemical sensor for 17 beta-estradiol (E2) based on the molecular imprinting polymer (MIP) membranes had been constructed. 6-mercaptonicotinic acid (MNA) and E2 were first assembled on the surface of platinum nanoparticles-modified glassy carbon electrode (PtNPs/GCE) by the formation of Pt-S bonds and hydrogen-bonding interactions, and subsequently the polymer membranes were formed by electropolymerization. Finally, a novel molecularly imprinted sensor (MIS) was obtained after removal of E2. Experimental parameters such as deposition time, scan cycles, pH value and accumulation condition were optimized. Under optimal conditions, the MIS exhibited a large adsorption capacity and high selectivity. A good linearity was obtained in the range of 3.0 x 10(-8)-5.0 x 10(-5) mol L(-1) (r = 0.996) with an estimated detection limit of 1.6 x 10(-8) mol L(-1). MIS had been successfully used to analyze E2 in water samples without complex pretreatment. Meanwhile, the average recoveries were higher than 93.9% with RSD < 3.7%. All results above reveal that MIS is an effective electrochemical technique to determine E2 real-time in complicated matrix. (C) 2011 Elsevier B.V. All rights reserved.