Nanoparticles gold nanospheres

The nanoparticles can be incorporated into cells by incubation the nanoparticies suspended in DMEM medium with the cells for 12 to 48 hours. From dark field light scattering imaging [54], it has been established that gold nanoparticies are taken intracellulariy into these cell lines. The nanoparticies are accumulated inside cytoplasm of live cells by receptor-mediated endocytosis processes. Figure 20.16 shows that for most of samples gold nanospheres quench the protein fluorescoice at 12 h incubation time. However, in some samples fluorescence enhancement is observed. 

Figure 20.15 . Fluorescence spectra of whole cells with and without gold nanospheres. Each cell type demonstrates characteristic decrease in fluorescence for all samples tested.X,exci = 280 nm. RFU relative fluorescence unites. NP nanoparticles. Cited from reference 52.

R. Pratibha, W. Park, LI. Smalyukh, Colloidal gold nanosphere dispersions in smectic liquid crystals and thin nanoparticle-decorated smectic films. J. Appl. Phys. 107, 63511 (2010)... 

In coupled nanoparticle systems, the distance between the nanoparticles plays a key role in the enhancement of the local field and SERS enhancement factor. The smaller the gap size of a gold nanosphere dimer, the stronger the extinction intensity, and the larger the maximum SERS enhancement factor. It is worth noting that, for small gaps, the enhancement factors increase much more quickly than the increase of extinction coeflBcient. More importantly, when the gap is close to 1-2 nm the enhancement factor in the gap can reach up to 10 to 10 °, and facilitates single-molecule detection [65]. 

FIGURE 13.11 Gold nanosphere albedo (a ratio of scattering to total extinction) as a function of nanoparticle diameter. From http //nanocomposix.com/kb/gold/optical-properties. 

Xiang, C., et al. Bienzymatic glucose biosensor based on direct electrochemistry of cytochrome c on gold nanoparticles/polyeuiiline nanospheres composite. Talanta 110, 96-100 (2013)... 

Figure 13.12 Plasmonic laser nanoablation (PLN) technique proposed by Ben-Yakar s group, (a) Theoretical calculations showing the field intensity around a gold nanosphere deposited on silicon substrate. The large enhancement of the ultrafast laser scattering in near-held of a gold nanoparticle can be used to ablate the silicon substrate immediately underneath the particle ...

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