Spectroscopic properties of hybrid systems carbazole@hydroxypropyl-b-cyclodextrin@silver nanoparticles.

IULIANA MIHALACHE; MATIAS CARRANZA; NATALIA L. PACIONI; ANTONIO RADOI; MIHAELA KUSKO; ALICIA VEGLIA

Carlos Paz, Córdoba

Conferencia; 13th Latin American Conference on Physical Organic Chemistry; 2015

Universidad Nacional de Córdoba

Physical chemistry of nanomaterials after improving the synthetic procedures to obtain themhas become a growing research area in the last decades, in order to understand their uniqueproperties beyond the surface Plasmon phenomena. On the other hand, supramolecularchemistry aims to interpret and design new chemical systems further than the covalent bond,building on supramolecular structures with specific new properties in molecular recognition,catalysis, separations and sensors, among others.It is known metal nanoparticles (NP) like gold (AuNP) and silver (AgNP) have acharacteristic extinction in the UV-visible region called Surface Plasmon Resonance Band(SPB) that is sensitive to several factors such as size, shape, coverage and interparticledistance. Moreover, this SPR has been proposed to produce interesting light-inducedphenomena on molecules in the vicinity of the metal surface.1 However, understanding wellwhat are the supramolecular chemistry characteristics behind these phenomena is stillunanswered. Our ultimate aim is to reveal what factors (and how) have a relevant role in thephysical chemistry properties of hybrid systems comprising supramolecular complexes and NP.Previous results obtained in the Argentinean group showed that Carbazole (CZL) interactswith hydroxypropyl-β-cyclodextrin (HPCD; KA = 1200 M-1) and as a result of this interaction theCZL fluorescence is enhanced around 1.5 times respect to the free guest in water and buffer pH7 media.In this work, we will present the effect of silver (AgNP) nanoparticles stabilized by differentligands on the spectroscopic properties (UV-visible, fluorescence and circular dichroism) of theCZL@HPCD complex. For example, addition of 50 nm AgNP quenched both, CZL andCZL@HPCD but the effect was more marked on the complex. In addition, induced circulardichroism signals were modified in the presence of AgNP indicating the their interaction with theCZL@HPCD system. We will discuss these results on the basis of the supramolecularchemistry principles.