TY - JOUR
T1 - Measuring surface charge density and particle height using surface plasmon resonance technique
AU - Shan, Xiaonan
AU - Huang, Xinping
AU - Foley, Kyle J.
AU - Zhang, Peiming
AU - Chen, Kangping
AU - Wang, Shaopeng
AU - Tao, Nongjian
PY - 2010
Y1 - 2010
N2 - We demonstrate a method to measure surface charge density and particle height using surface plasmon resonance (SPR) detection. It is based on two facts: (1) The equilibrium height of a charged particle over a charged surface depends on the electrostatic interaction between the particle and the surface; and (2) SPR is extremely sensitive to the height of the particle. We perform numerical simulations to establish the relations between the SPR signal and the particle height, and between the particle height and the surface charge density, and carry out systematic experiments, including effects of different buffer concentrations, particle sizes, and concentrations, to examine the relations. The simulation and experimental results are in good agreement with each other. Using the method, we determine surface charge density of gold surface functionalized with different molecules. If the surface charge density is known, the method can also be used to determine the charges of the particles.
AB - We demonstrate a method to measure surface charge density and particle height using surface plasmon resonance (SPR) detection. It is based on two facts: (1) The equilibrium height of a charged particle over a charged surface depends on the electrostatic interaction between the particle and the surface; and (2) SPR is extremely sensitive to the height of the particle. We perform numerical simulations to establish the relations between the SPR signal and the particle height, and between the particle height and the surface charge density, and carry out systematic experiments, including effects of different buffer concentrations, particle sizes, and concentrations, to examine the relations. The simulation and experimental results are in good agreement with each other. Using the method, we determine surface charge density of gold surface functionalized with different molecules. If the surface charge density is known, the method can also be used to determine the charges of the particles.
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U2 - 10.1021/ac901816z
DO - 10.1021/ac901816z
M3 - Article
C2 - 19938822
AN - SCOPUS:75749131640
SN - 0003-2700
VL - 82
SP - 234
EP - 240
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 1
ER -