Antibody-based sensors for heavy metal ions.

Competitive immunoassays for Cd(II), Co(II), Pb(II) and U(VI) were developed using identical reagents in two different assay formats, a competitive microwell format and an immunosensor format with the KinExA 3000. Four different monoclonal antibodies specific for complexes of EDTA-Cd(II), DTPA-Co(II), 2,9-dicarboxyl-1,10-phenanthroline-U(VI), or cyclohexyl-DTPA-Pb(II) were incubated with the appropriate soluble metal-chelate complex. In the microwell assay format, the immobilized version of the metal-chelate complex was present simultaneously in the assay mixture. In the KinExA format, the antibody was allowed to pre-equilibrate with the soluble metal-chelate complex, then the incubation mixture was rapidly passed through a microcolumn containing the immobilized metal-chelate complex. In all four assays, the KinExA format yielded an assay with 10-1000-fold greater sensitivity. The enhanced sensitivity of the KinExA format is most likely due to the differences in the affinity of the monoclonal antibodies for the soluble versus the immobilized metal-chelate complex. The KinExA 3000 instrument and the Cd(II)-specific antibody were used to construct a prototype assay that could correctly assess the concentration of cadmium spiked into a groundwater sample. Mean analytical recovery of added Cd(II) was 114.25+/-11.37%. The precision of the assay was satisfactory; coefficients of variation were 0.81-7.77% and 3.62-14.16% for within run and between run precision, respectively.

[1]  C. Barbas,et al.  Direct selection of antibodies that coordinate metals from semisynthetic combinatorial libraries. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[2]  R. Blake,et al.  Immunoassays for metal ions , 1998 .

[3]  C. Meares,et al.  Antibodies against metal chelates , 1985, Nature.

[4]  M. Fingerman,et al.  Inhibition of acetylcholinesterase activity in the central nervous system of the red swamp crayfish, procambarus clarkii, by mercury, cadmium, and lead , 1995, Bulletin of environmental contamination and toxicology.

[5]  D. Wylie,et al.  Metal Binding Properties of a Monoclonal Antibody Directed toward Metal-Chelate Complexes* , 1996, The Journal of Biological Chemistry.

[6]  H. Ensley,et al.  Antibodies and antibody-based assays for hexavalent uranium , 2001 .

[7]  M. Brechbiel,et al.  Binding properties of a monoclonal antibody directed toward lead-chelate complexes. , 2000, Bioconjugate chemistry.

[8]  J Greve,et al.  The waveguide Mach-Zender interferometer as atrazine sensor. , 1998, Analytical chemistry.

[9]  G. Meyer.  Still the Panacea for Trace Metals Analysis , 1987 .

[10]  G G Guilbault,et al.  A piezoelectric immunobiosensor for atrazine in drinking water. , 1992, Biosensors & bioelectronics.

[11]  G. K. Pagenkopf.  KINETICS AND MECHANISMS OF COMPLEX FORMATION AND LIGAND EXCHANGE , 1978 .

[12]  A. Kusterbeck,et al.  Trace level detection of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by microimmunosensor. , 1999, Biosensors & bioelectronics.

[13]  U. Narang,et al.  Fiber optic-based biosensor for ricin. , 1997, Biosensors & bioelectronics.

[14]  Diane A. Blake,et al.  Detection of Heavy Metals by Immunoassay: Optimization and Validation of a Rapid, Portable Assay for Ionic Cadmium , 1998 .

[15]  S. Schuster,et al.  Monoclonal antibodies specific for mercuric ions. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[16]  J. Frincke,et al.  Kinetics of the dissociation of indium-(p-substituted-benzyl)ethylenediaminetetraacetic acid hapten analogues from the monoclonal anti-hapten antibody CHA255. , 1990, Bioconjugate chemistry.

[17]  A. Székács,et al.  Rapid assays for environmental and biological monitoring. , 1996, Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes.