Synthesis of Gold Nanoparticles as optical sensor functionalized with fluorescence dye for biologically active molecules

WANG, CHIEN CHUN; FELICI, EMILIANO; GOMEZ, ROXANA A.; FERNANDEZ, LILIANA

cÓRDOBA

Congreso; III Reunión Internacional de Ciencias Farmacéuticas.; 2014

Reunión Internacional de Ciencias Farmacéuticas (RICIFA 2014)

Nanoparticles (NPs) have been used in variety of detecting molecules because of their unique physical and optical properties, related to their high surface-to-volume ratio, excellent biocompatibility after appropriate modification and offer a platform for functionalization with ligands for the specific sensing of targets. In optical field, noble metals as Gold (Au) and Silver (Ag) NPs were of interest for developing optical sensors due to their high surface plasmon resonance, which lead to a strong absorption band. Therefore, AuNPs were widely applied for detection of several analites by spectroscopical techniques. Within potential applications of these sensors, it is worthy to mention analytes of pharmaceutical interest. The aim of this work is to developing optical nanosensors funcionalized with highly fluorescence molecules, for further applications to determine biologicaly active molecules. For this purpose, AuNPs were synthesized by a heat reduction process of HAuCl4 with trisodium citrate. After purification this nanoparticles where functionalized with rhodamine B (RdB) by intection between colloide and dye solution. The concentrations and characterization of RdB-AuNPs were taken by spectofotometry and spectrofluorimetry. These optical nanoprobes have advantage of being stable, low cost and high biocompatibility. Due to the affinity of metal surface to sulfhydryl groups, AuNPs are highly sensitive to the presence of biologically active amines. Moreover, the fluorescence dye used for AuNP coating enhance the detection limits.