Abstract
Taking advantage of recent developments in the field of metallic nanoparticle-based colorimetric DNA detection and in the field of in vitro selection of functional DNA/RNA that can recognize a wide range of analytes, we have designed highly sensitive and selective colorimetric biosensors for many analytes of choice. As an example of the sensor design strategy, a highly sensitive and selective colorimetric lead biosensor based on DNAzyme-directed assembly of gold nanoparticles is reviewed. The DNAzyme consists of an enzyme and a substrate strand, which can be used to assemble DNA-functionalized gold nanoparticles. The aggregation brings gold nanoparticles together, resulting in a blue-colored nanoparticle assembly. In the presence of lead, the DNAzyme catalyzes specific hydrolytic cleavage of the substrate strand, which disrupts the formation of the nanoparticle assembly, resulting in red-colored individual nanoparticles. The application of the sensor in lead detection in leaded paint is also demonstrated. In perspective, the use of allosteric DNA/RNAzymes to expand the range of the nanoparticle-based sensor design method is described.
Original language | English (US) |
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Pages (from-to) | 343-354 |
Number of pages | 12 |
Journal | Journal of Fluorescence |
Volume | 14 |
Issue number | 4 |
DOIs | |
State | Published - Jul 2004 |
Keywords
- Aptamers
- Biosensors
- Colorimetric
- DNAzymes
- Nanoparticles
ASJC Scopus subject areas
- Analytical Chemistry
- Clinical Biochemistry