Abstract: An electrochemical technique for preparation of a molecularly imprinted overoxidized polypyrrole (oPPy) film and its recognition property for bile acids are investigated, aiming for application to a bile acid sensor and clarification of the principle of the recognition mechanism with the quartz crystal microbalance. The molecularly imprinted oPPy has been prepared through a potentiodynamical overoxidation process in an alkaline solution from a taurocholate (TC) doped polypyrrole (PPy) film grown on an Au electrode. The molecularly imprinted film exhibited a high selectivity and sensitivity toward bile acids. Cholate, chenodeoxycholate, deoxycholate, TC, and artificially synthesized dehydrocholate showed a linear relationship between the resonance frequency and their logarithmic concentrations in a range from 10(-9) to 10(-5) M with detection limits for trace concentrations (similar to 25 nM). The sensitivity of an oPPy film imprinted with TC increased in the sequence of TC (28.8 Hz/log concentration) < cholate (72.7) < chenodeoxycholate (73.8) <= deoxycholate (73.7) < dehydrocholate (82.0), and was found to depend on the molecular volume of bile acids (increasing in the sequence TC > cholate > chenodeoxycholate >= deoxycholate > dehydrocholate). (c) 2005 The Electrochemical Society. All rights reserved
Template and target information: bile acids, cholate, chenodeoxycholate, deoxycholate, taurocholate, TC
Author keywords: electrochemistry, chemical sensors, oxidation, organic compounds, biological techniques, biochemistry, molecular biophysics