Molecularly imprinted TiO2 thin film using stable ground-state complex as template as applied to selective electrochemical determination of mercury

Molecular recognition sites for mercury ions were imprinted in TiO2 film using stable ground-state complex of 1-amino-8-naphtol-3,6-disodium sulfonate (ANDS) and mercury ions as template. The complex ratio between mercury ions and ANDS was estimated to be 2:1. Compared with the controlled and pure TiO2 electrodes, the imprinted electrode revealed selectivity towards the imprinted ions. Linear calibration plots for mercury ions were obtained and the regression equation was I-p (mu A) = 4.29 x 10(-7)+ 19.40 [Hg2+] with a detection limit of 3.06 x 10(-9) mol/l. The imprinted electrode could be used for more than 1 month. Recoveries were calculated at both high and low concentrations, with a mean recovery of 99.6%. (c) 2005 Elsevier B.V. All rights reserved.