IEC 80 |
| Joseph Wang, Department of Chemistry and Biochemistry, Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003 |
| The unique properties of nanoparticle-based materials, and the versatility of microspheres, in general, offer excellent prospects for DNA analysis. This presentation will describe new multi-amplification/multi-tag particle-based electrical assays based on a variety new DNA-particle nanostructured materials. In particular, combining the catalytic enlargement of the metal-particle tags, with the effective ‘built-in’ amplification of electrochemical stripping analysis, paved the way to remarkably low (fmol) detection limits. The high sensitivity of the silver-enhanced colloidal gold stripping detection was combined with an efficient magnetic separation. Such use of magnetic beads has been extremely useful for discriminating against unwanted constituents, including a large excess of co-existing mismatched and non-complementary oligomers, chromosomal DNA, RNA and proteins. TEM imaging has indicated that the DNA hybrid links the metal nanoparticles to the magnetic beads. No such aggregates were observed in the presence of noncomplementary or mismatched DNA. The magnetic bead capture was also combined with a label-free detection of DNA hybridization based on highly-sensitive stripping potentiometric measurements of the target guanine. The attractive bioanalytical behavior of the new particle-based electrical assays will be illustrated in connection to the detection of DNA segments related to the breast-cancer BRCA1 gene. Current efforts in our SensoChip Lab are aimed at developing new multi-amplification/multi-tag particle-based bioassays and transforming them to microchip platforms.
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Nanoscale Sensing Technology: Why and How? (sponsored by Advanced Materials & Nanotechnology Subdivision)
2:00 PM-5:05 PM, Monday, March 24, 2003 Convention Center -- Room 394, Oral
Division of Industrial and Engineering Chemistry |