Silver nanoparticles photosensitization

Gold nanoparticles are virtually not luminescent, but silver nanoparticles show plasmon emissions with reasonable quantum yields. Furthermore, the non-radiative decay, resulting in electron-hole pair generation, may be used for photosensitization of wide bandgap semiconductors (see Figure 7.5) [16,17]. Similar effects may also be observed as direct photoinduced electron transfer between metal surfaces and surface-bound molecules [18]. 

Since enhanced electromagnetic fields in proximity to metal nanoparticles are the basis for the increased system absorption, various computational methods are available to predict the extent of the net system absorption and therefore potentially model the relative increase in singlet oxygen generation from photosensitizers. " In comparison to traditional Mie theory, more accurate computational methods, such as discrete dipole approximation (DDA/ or finite difference time domain (FDTD) methods, are often implemented to more accurately approximate field distributions for larger particles with quadruple plasmon resonances, plasmon frequencies of silver nanoparticles, or non-spherical nanoparticles in complex media or arrangements. ... 

Metal particles are most conveniently grown on the clay mineral surface by displacing the exchangeable cation by precursor transition-metal cations and by subsequent reduction. Au and Ag clusters were obtained in laponite clay mineral of synthetic origin by Aihara et al. [9] using this method with sodium borohydride as a reducing agent. Silver nanoparticles are widely used as photosensitive components [10], as catalysts [11], in photocatalysis [12], and in surface-enhanced Raman... 

In a second step, the in-situ synthesis of Ag NPs within the microfibrous scaffold is implemented by photoreduction reaction in the presence of both a silver precursor and a photosensitizer. SEM and TEM experiments confirm the formation and dispersion of Ag NPs on the surface of the modified fibers (Fig. 6.11). PHBHV microfibrous scaffolds including silver nanoparticles led to a tremendous inhibition of the adhesion of E. Coli and a reduction by 98% of the adherence of S. aureus. 

E.A. Moulin, U.W. Paetzold, B.E. Pieters, W. Reetz, R. Caiius, Plasmon-induced photoexcitation of hot electrons and hot holes in amorphous silicon photosensitive devices containing silver nanoparticles. J. Appl. Phys. 113, 144501 (2013)... 

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