Extrinsic Raman labels for SERS readout in immunosorbent assays: Cubic and spherical gold nanoparticles

ANYL 323

Radha Narayanan, radhan@iastate.edu1, Robert J. Lipert, blipert@porter1.ameslab.gov1, and Marc D. Porter, mporter@porter1.ameslab.gov2. (1) Department of Chemistry, Institute of Combinatorial Chemistry, Ames Laboratory-USDOE, Iowa State University, Ames, IA 50011, (2) Department of Chemistry and of Chemical and Biological Engineering, Institute for Combinatorial Discovery, Ames Laboratory-USDOE, Iowa State University, 42 Spedding Hall, Ames, IA 50011
This presentation describes results from the first extension of particle shape in the construction of extrinsic Raman labels (ERLs) in immunosorbent assays. ERLs, applied in the last step of the assay, are sensitive tags for captured antigens, with detection limits at low femtomolar levels in early disease detection (cancer biomarkers)1 and bioterrorism prevention (viruses).2 This presentation compares the detection limit obtained for ERLs based on standard spherical citrate capped gold nanoparticles (s-Cit-Au) with those for CTAB-stabilized spherical (s-CTAB-Au) and cubic gold nanoparticles (c-CTAB-Au) in the SERS readout for human IgG. With respect to s-Cit-Au, the detection limit is 37 times lower with s-CTAB-Au and 300 times lower with the c-CTAB-Au. These findings, along with assessments of underlying factors that contribute to these differences, will be discussed.

1) D. Grushiba, R. Lipert, H.Park, J. Driskell, M. Porter, Anal. Chem. 2003 75, 5936.

2) J. Driskell, K. Kwarta, R. Lipert, M. Porter, J. Neill, J. Ridpath, Anal. Chem. 2005, 19, 6147.

 

Analytical Approaches: Sensors
1:30 PM-4:20 PM, Thursday, 14 September 2006 Moscone Center -- Room 123, Oral

Division of Analytical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006