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 β-cyclodextrin (6-(2-mercapto-ethylamino)-6-deoxy-β-cyclodextrin (MEA-β-CD)) was prepared and modified on a gold electrode (MCGE) for specific Pb2+-sensing. Thus the mercury-free sensors for Pb2+ assay based on MCGE were established. A linear calibration response for Pb2+ was found in the range of 1.7 × 10−8 M to 9.3 × 10−7 M. The detection limit was 7.1 × 10−9 M (with S/N > 3), which was 10 times lower than other reported methods of detection Pb2+ 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 Pb2+ in real blood samples.