Quantum dots assays

Swift, J. L., Heuff, R. F. and Cramb, D. T. (2006) A two-photon excitation fluorescence cross-correlation assay for a model ligand-receptor binding system using quantum dots. Biophys. J., 90, 1396-1410. 

Silica particles have been exploited in virtually every assay or detection strategy that polymer particles have been used in for bioapplication purposes. Recently, fluorescent dye-doped silica nanoparticles have been developed by a number of groups that have similar fluorescence characteristics to quantum dot nanocrystals (Chapter 9, Section 10). Fluorescent silica nanoparticles can be synthesized less expensively than quantum dots due to the fact that the silica particles incorporate standard organic dyes (Ow et al., 2005 Wang et al., 2006) and are not dependent on making reproducible populations of semiconductor particles with precise diameters to tune emission wavelengths. 

Other fluorescent probes also may be used to label (strept)avidin molecules for detection of biotinylated targeting molecules. Chapter 9 reviews many additional fluorescent labels, such as quantum dots, lanthanide chelates, and cyanine dye derivatives, all of which may be used in similar protocols to create detection conjugates for (strept)avidin-biotin-based assays. 

Xu H, Sha MY, Wong EY, Uphoff J, Xu Y, Treadway JA, Truong A, O Brien E, Asquith S, Stubbins M, Spurr NK, Lai EH, Mahoney W. Multiplexed SNP genotyping using the Qbead system a quantum dot-encoded microsphere-based assay. Nucleic Acids Res 2003 31 e43. 

Applications of quantum dots include optical detection of genes and proteins in animal models and cell assays and tumor and lymph node visualization through imaging [67,68],... 

Similarly to the methods based on absorbance, assays that measure fluorescence have to be conducted taking care that all necessary controls are considered, since NMs could interfere in the assessment of the emitted light in a number of ways. NMs can have their own fluorescence (e.g., quantum dots), might quench the fluorescence of the measured dye (e.g., gold NPs), reflect the excitation light (e.g., Ti02 NPs), or physically block the emitted light (e.g., carbon black). 

Pellegrino, T., et ah. Quantum dot-based cell motility assay. Differentiation 2003, 71, 542-548. 

Xu, H., et ah. Multiplexed SNP genotyping using the Qbead system a quantum dot-encoded microsphere-based assay. Nucleic Acids Res 2003, 31, e43. 

Goldman ER, Mattoussi H, Anderson GP, Medintz IE, Mauro JM. Eluoroimmuno-assays using antibody-conjugated quantum dots. Methods Mol Biol 2005 303 ... 

Bhahdigadi, S., Rao, P., Kiel, J. L., Andrews, C. J. (2007). Fluorescence assay based on aptamer-quantum dot binding to Bacillus thuringiensis spores. J Fluoresc 17, 193-199. 

Figure 8.5 (A) Quantum dot aptamer assay for the detection of thrombin. The quan-...

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