TY - JOUR
T1 - Surfactant-free coating of thiols on gold nanoparticles using sonochemistry: A study of competing processes
AU - Pallipurath, Anuradha
AU - Nicoletti, Olivia
AU - Skelton, Jonathan
AU - Mahajan, Sumeet
AU - Midgley, Paul
AU - Elliott, Stephen
PY - 2014/9
Y1 - 2014/9
N2 - A method for the surfactant-free coating of gold nanoparticles with thiols using sonochemistry is presented. The gold nanoparticles were prepared by a modified Zsigmondy method, affording good con- trol over the particle-size distribution, and the thiol coating was performed by the sonication of a bipha- sic system consisting of a nanoparticle suspension in water and thiols in toluene. The effects of two important reaction parameters on the particle morphology, viz. sonication time and thiol concentration, were investigated in detail using transmission electron microscopy. The effect of the thiol chain length was also studied. We show that the morphology of the coated particles is determined through a compe- tition between two opposing effects: particle fusion, due to the sonication conditions, and digestive rip- ening, due to the action of the thiols. Additionally, we illustrate the utility of our technique for various applications, including surface-enhanced Raman scattering from bound molecules, and further function- alization using a thiol-exchange reaction. Our technique paves the way for an efficient synthesis of thiol- coated AuNPs of different shapes and sizes, suitable for a range of diverse applications.
AB - A method for the surfactant-free coating of gold nanoparticles with thiols using sonochemistry is presented. The gold nanoparticles were prepared by a modified Zsigmondy method, affording good con- trol over the particle-size distribution, and the thiol coating was performed by the sonication of a bipha- sic system consisting of a nanoparticle suspension in water and thiols in toluene. The effects of two important reaction parameters on the particle morphology, viz. sonication time and thiol concentration, were investigated in detail using transmission electron microscopy. The effect of the thiol chain length was also studied. We show that the morphology of the coated particles is determined through a compe- tition between two opposing effects: particle fusion, due to the sonication conditions, and digestive rip- ening, due to the action of the thiols. Additionally, we illustrate the utility of our technique for various applications, including surface-enhanced Raman scattering from bound molecules, and further function- alization using a thiol-exchange reaction. Our technique paves the way for an efficient synthesis of thiol- coated AuNPs of different shapes and sizes, suitable for a range of diverse applications.
UR - http://www.sciencedirect.com/science/article/pii/S1350417714001047
U2 - 10.1016/j.ultsonch.2014.03.014
DO - 10.1016/j.ultsonch.2014.03.014
M3 - Article
SN - 1350-4177
VL - 21
SP - 1886
EP - 1892
JO - Ultrasonics Sonochemistry
JF - Ultrasonics Sonochemistry
IS - 5
ER -