Photophysical and photochemsitry to differentiate between meal nanoparticles in mixtures: an Analytical Strategy.

NATALIA L. PACIONI; SANTIAGO D. SALAS; VEGLIA, A. V.

Sarasota

Congreso; 22 nd Winter Inter-American Photochemical Society Meeting.; 2013

Inter-American Photochemical Society

Research on environmental and health consequences that could be produced by the increasinguse of nanomaterials (eg. metal nanoparticles, NM) is still in their infancy. The success ofthese research fields as well as the establishment of new regulations for these emergingpollutants is closely related to the availability of reliable analytical methods that permit todistinguish and quantify different NM. Nevertheless, there is still a lack of standarizedanalytical methods to detect and evaluate NM in environmental samples. Regarding to this,one of the main challenges we currently are facing is the development of strategies that allowus to detect these nanoparticles and to facilitate their quantification in environmentalstudies.[1]Among their unique properties, NM like gold and silver have a characteristic extinction in theUV-visible region named as Surface Plasmon Resonance Band (SPB) that is sensitive toseveral factors such as size, shape, coverage and interparticle distance; and that has beenproved to produce interesting light-induced phenomena on molecules in the vicinity of themetal surface.[2]Presented here are some examples of developing analytical strategies in our group todistinguish between different gold and silver nanoparticles in mixtures. These methods arebased on the specific and/or selective interaction between the NM and, molecular andsupramolecular switches that induces variations on the photophysics or photochemistry of theinteracting systems. For example, these modifications are reflected by changes either on thenanoparticle SPB or on the spectroscopic properties such as absorption, fluorescence, inducedcircular dichroism of the interacting species observed as a shift in the position of the signalsand either enhancement or decrease of their intensity.