3.1 Enlarging diameter of AuNPs in ES-SMPS
After mixing the original AuNP solutions and AmAc solution and having
the final AmAc concentration of 20 mM, Au-10 and Au-5 suspensions were
loaded to ES-SMPS system for the size scanning. Multiple peaks among the
size distributions of both AuNP samples were found, as displayed inFigure 2(A) & (D) , and were considered as the
influence of the surfactant or other impurity existing in the original
AuNP solution. The centrifugal process replaced the most of the solvent
in the original AuNP solution with deionized water/AmAc solution, andFigure 2(B) & (E) exhibited the reduction in
surfactant/impurity in the AuNP suspensions as the dramatically decrease
of NP numbers and disappearance of the peaks positioning at smaller
diameters. In according with the size distribution of AuNP samples with
centrifugal treatments, the diameters of Au-10 and Au-5 from the
original solution were determined as 12.6 nm and 10.6 nm, which
presented a respective difference of 26 % and 112 % from the nominal
diameter.