Gold nanoparticles fluorescent quenching

PPEs have been around now for more than 20 years, and a number of reviews have appeared dealing with this topic (Table 8.1). PAEs are successful in the solubilization of carbon nanotubes,and in the detection of lectins and bacteria. " Ionic PPEs are used in the presence of cationic gold nanoparticles. The formed PPE-particle constructs are nonfluorescent, as the cationic gold nanoparticles strongly quench the emission of PPEs. These constructs detect proteins, cell states, bacteria and other analytes through the disruption of the complexes under turn on of the fluorescence and its quantification. A review about this topic has appeared. However, even a collection of chemically different, water-soluble PPEs in an array format is able to discern different proteins quite well even without the presence of gold nanoparticles. PPEs are now applied in a wide array of different electronic and sensory applications. In the next parts of this review we will cover how to make PPEs and look into significant experimental details of how to produce them. 

Dulkeith, E., Ringler, M., Klar, T. A., Feldmann, J., Javier, A. M. and Parak, W. J. (2005). Gold nanoparticles quench fluorescence by phase induced radiative rate suppression. Nano Lett. 5 585-589. 

Schneider, G., Decher, G., Nerambourg, N., Praho, R., Werts, M. H. V. and Blanchard-Desce, M. (2006). Distance-dependent fluorescence quenching on gold nanoparticles ensheathed with layer-by-layer assembled polyelectrolytes. Nano Lett. 6 530-536. 

Figure 20.6 Schematic diagram of the DNA detection using fluorescence quenching by gold nanoparticles. Oligonucleotide molecules are conjugated to gold surface vial Au-S bonds and the fluorescein molecules at the other end of the oligo sequence is adsorbed onto gold nanoparticles to form a constrained conformation.

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