Gold Nanoparticle Adsorption and Aggregation Kinetics at the Silica−Water Interface

Fisk, Jonathan D., Rooth, Maxim and Shaw, Andrew M. (2007) Gold Nanoparticle Adsorption and Aggregation Kinetics at the Silica−Water Interface. The Journal of Physical Chemistry C, 111 (6). pp. 2588-2594. ISSN 1932-7447

Full content URL: https://doi.org/10.1021/jp063759r

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Item Type:Article
Item Status:Live Archive

Abstract

Gold nanoparticles have been synthesized as colloids using a citrate and borohydride reduction of auric chloride producing 15 and 45 nm particles, respectively. The nanoparticle adsorption kinetics have been observed at the silica-water interface by evanescent wave cavity ring-down spectroscopy. AFM images have been used to determine the surface coverage from which the extinction coefficients of the particles in water have been determined at two interrogation wavelengths: 15 nm particles is an element of(635 nm) = 6.4 +/- 1.6 x 10(7) M-1 cm(-1), is an element of(830 rim) 9.8 +/- 0.2 x 10(6) M-1 cm(-1); and 45 nm particles is an element of(635 nm) = 3.1 +/- 1.8 x 10(9) M-1 cm(-1), is an element of(830 nm) = 9.2 +/- 1.5 x 10(8) M-1 cm(-1). These values are larger than the Mie scattering calculations would predict. Mono: and multilayer adsorption kinetics have been observed with monolayer binding constants KD = 2.75 +/- 0.55 nM for the 15 nm particles and 0.74 +/- 0.47 nM for the 45 nm particles. An initial slope analysis of the binding kinetics shows the 15 mn particles undergo aggregation at the surface whereas the 45 nm particles do not. A multilayer co-operative sequential adsorption aggregation model is developed indicating that goldgold particle aggregation affinity is not as strong as the affinity of the gold to the surface. The refractive index sensitivity of the resulting particle plasmon surfaces has been measured, and the surfaces are sensitive to changes of typically 7 x 10(-4) but optimally 2.5 x 10(-6).

Keywords:gold nanoparticles, SPR, surface plasmon resonance, cavity ring-down, e-CRDS
Subjects:F Physical Sciences > F112 Colour Chemistry
F Physical Sciences > F300 Physics
F Physical Sciences > F361 Laser Physics
F Physical Sciences > F100 Chemistry
F Physical Sciences > F170 Physical Chemistry
F Physical Sciences > F320 Chemical Physics
F Physical Sciences > F360 Optical Physics
F Physical Sciences > F110 Applied Chemistry
F Physical Sciences > F180 Analytical Chemistry
Divisions:College of Science > School of Geography
ID Code:47609
Deposited On:26 Jan 2022 15:58

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