Gold/silver nanoparticles

Lu LH, Wang HS, Zhou YH, Xi SQ, Zhang HJ, Jiawen HBM, Zhao B (2002) Seed-mediated growth of large, monodisperse core-shell gold-silver nanoparticles with Ag-like optical properties. Chem Commun, pp 144-145... 

The reported strategies utilized in DNA sensing include (1) sequence-specific hybridization processes based on the oxidation signal of most electroactive DNA bases, guanine and adenine [13,24] or (2) quasi-specific detection of small molecules capable of binding by intercalation or complexation with DNA, such as metal coordination complexes, antibiotics, pesticides, pollutants, etc. [17,18] or in the presence of some metal tags such as gold, silver nanoparticles, etc. [23,50,51]. 

Link S, Wang Z.L. and El-Sayed M.A., (1999) Alloy formation of gold-silver nanoparticles and the dependence of the plasmon absorption on their composition, J. Phys. Chem. B 103 3529-3533. 

S. Link Z. L. Wang M. A. El-Sayed, Alloy Formation of Gold-Silver Nanoparticles and the Dependence of the Plasmon Absorption on Their Composition./. Phys. Chem. B 1999, 303, 3529-3533. 

Furthermore, the dense, saturation packing of R6G or other dye molecules on colloidal gold/silver surface does not limit Raman intensities in the way that fluorescence intensities are lowered by excited state dipole-dipole interactions. In comparison with flnorescent dyes and quantum dots, the enhanced Raman probes have an intrinsic amplification mechanism, with improved encoding and mnltiplexing capabilities. If multiple (4 or even more) sizes of gold/silver nanoparticles in the 50-300 nm diameter range with a narrow size distribution can be prepared, and then loaded with 20 different dye molecules with unique SERS fingerprints, this would provide 80 probes for each metal nanoparticle. 

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