Highly sensitive and reproducible cyclodextrin-modified gold electrodes for probing trace lead in blood

A highly sensitive and reproducible lead sensor based on a cyclodextrin-modified gold electrode was created. A self-assembled monolayer (SAM) of thiolated beta-cyclodextrin (6-(2-mercapto-ethylamino)-6-deoxy-beta-cyclodextrin (MEA-beta-CD)) was prepared and modified on a gold electrode (MCGE) for specific Pb(2+)-sensing. Thus the mercury-free sensors for Pb(2+) assay based on MCGE were established. A linear calibration response for Pb(2+) was found in the range of 1.7 x 10(-8)M to 9.3 x 10(-7)M. The detection limit was 7.1 x 10(-9)M (with S/N>3), which was 10 times lower than other reported methods of detection Pb(2+) with CD. The measurement results via this method for real blood samples were well agree with those obtained by ICP-AES, and thus presented a novel strategy in design of specific lead sensors with high sensitivity and stability for analysis of trace Pb(2+) in real blood samples.