Optically-tunable nanoparticles

Owing to their unique (tunable-electronic) properties, semiconductor (quantum dots) nanocrystals have generated considerable interest for optical DNA detection [12], Recent activity has demonstrated the utility of quantum dot nanoparticles for enhanced electrical DNA detection [33, 34, 50], Willner et al. reported on a photoelectrochemical transduction of DNA sensing events in connection with DNA cross-linked CdS nanoparticle arrays [50], The electrostatic binding of the Ru(NH3)63+ electron acceptor to the dsDNA... 

Synthesis of novel materials with desired and tunable physical and chemical properties continues to draw wide interest. Nanomaterials with a variety of shapes and sizes have been synthesized as they offer numerous possibilities to study size and shape-dependent variations of electronic, optical, and chemical properties. Nanomaterials of a particular element show drastic differences in physical and chemical properties when compared with the bulk state. For example, bulk gold, a metal that is insoluble in water can be made dispersible when it is in the nanoparticle form. There are drastic changes in the optical properties as well. Bulk gold appears yellow in color, but when it is in the nanoparticle form with an average core diameter of 16 nm, it appears wine red. Likewise, the chemistry of gold, such as catalysis, also shows a drastic change when the constituent units are in the nanometer range. 

Conventional SERS substrates typically have disordered nanoscale features, such as that found in electrochemically roughened Au or Ag surfaces.170 SERS substrates can also be rationally designed by lithography, by self-assembly, or a combination of the two. Both supramolecular and nanoscale self-assembly methods can be used to fabricate two-dimensional Au nanoparticle arrays with tunable optical properties.33 171172 For example, macrocyclic surfactants based on resorcinarenes (a subclass... 

These results pave the way to functional nanoparticles where the size, shape, and iron oxide concentration can be controlled leading to tunable magnetic and optical properties of nanostructures on surfaces and interesting research in catalysis, molecular labeling, and detection, as well as controlled dmg delivery using external magnetic fields. 

Synthesis of metal nanostructures with tunable properties (optical, magnetic, electronic, catalytic, etc.), in specific physicochemical environments, is today of great importance from a fundamental as well as an applied point of view. Since the physicochemical properties of nanostructures are strongly dependent not only on the size but also on the shape, controlling the architecture of metal nanoparticles... 

Whelan, A. M., Brennan, M. E., Blau, W. J. and Kelly, J. M. (2004). Enhanced third-order optical nonlinearity of silver nanoparticles with a tunable surface plasmon resonance. J. Nanosci. Nanotechnol. 4 66-68. 

A. S. Zelenina, R. Qnidant, G. Badenes, and M. Nieto-Vesperinas, Tunable optical sorting and manipulation of nanoparticles via plasmon excitation. Optics Letters 31 p. 2054-2056 (2006). 

Size-tunable and water-soluble silver nanoparticles have been successfully synthesized with the assistance of glutathione. The optical properties of surface-modifiable silver nanoparticles depend on their size and the surface modification. Silver nanoparticles with an average diameter of 6 run effectively suppress the proliferation of human leukemia cells in the dose- and time-dependent manners, suggesting their promising application in cancer therapy [13]. 

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