An immunosensor for autonomous in-line detection of heavy metals: validation for hexavalent uranium

Abstract

An automated immunosensor, based on the commercially available KinExA 3000™, has been developed as a collaboration between academia and industry. The sensor had the ability to autonomously run a standard curve from stock reagents and to prepare environmental samples for analysis. Assays for both a model analyte (biotin) and the environmental contaminant hexavalent uranium (

) have been constructed. The sensor measured biotin at levels from 20 to 1000 nM and

at concentrations from 5.8 to 100 nM (1.4–24 ppb). The coefficients of variation (CV) in the uranium assay ranged from 3.5 to 5.9%, with an average of 4.6%. Spike-and-recovery experiments in the uranium assay yielded a mean % recovery of 99.17 ± 7.05. The sensitivity and specificity of this uranium sensor will support the rapid, inexpensive analysis of hexavalent uranium in both environmental and clinical samples.

Keywords:

• Immunosensor
• Flow fluorimeter
• Monoclonal antibodies
• Uranium
• Heavy metals
• Biotin

Acknowledgments

This work was supported by Grants DE-FG02-98ER62704 and DE-FG-02-02ER634559 to D.A.B. from the Office of Science (BER), US Department of Energy. The authors thank Xiaoyu Yang for preparing the graphics in figure 1.