Revista de nanomateriales y nanotecnología molecular

Rapid Induced Aggregation of Gold Nanoparticles by Diolefinic Dyes

Ahmed A Abo-Alhasan, Samy A El-Daly, Morad M El-Hendawy, Shahar H El-Khalfy and El-Zeiny M Ebeid

Rapid Induced Aggregation of Gold Nanoparticles by Diolefinic Dyes

Aggregation kinetics of gold nanoparticles (Au NPs) interaction in the presence of some diolefinic dyes, namely 1,4-bis (β-pyridyl-2-vinyl) benzene (P2VB), 1,4 bis(2-methylstyryl) benzene (MSB) and 2,5 distyrylpyrazine (DSP), were studied in methanol using steady state UV-Vis spectrophotometry and stopped-flow spectrophotometry. All three dyes induced the aggregation of Au NPs, but with different rates. The rate of interaction of P2VB and MSB with Au NPs were in time-scale of milliseconds, 6 ms-1 and 3.25 ms-1, respectively, while the interaction between DSP and Au NPs occurred in time-scale of minutes. The rates of interaction between Au NPs and these dyes go in the order of P2VB > MSB » DSP. The density functional theory (CAM-B3LYP) predicted that the dye with higher group charge on the terminal moieties possess higher affinity toward the aggregation as it strengthen its electrostatic interactions with the citrate-capped Au NPs.