基于纳米银聚集的共振散射光谱法测定痕量多巴胺

Determination of Trace Dopamine by Resonance Light Scattering Method Based on the Aggregation of Silver Nanoparticles

在弱酸性缓冲溶液中,质子化的多巴胺与表面包裹着柠檬酸根负离子的纳米银相结合,引起纳米银的聚集,导致体系在442 nm处共振散射强度增强,其强度增加值与多巴胺浓度呈线性关系,据此提出了一种利用纳米银的聚集效应采用共振散射技术测定痕量多巴胺的新方法。在选定最佳实验条件下,多巴胺的线性范围为1.0×10^(-7)~2.5×10^(-5)mol/L,线性回归方程为ΔI=2.808×10~7c+8.15,相关系数为0.999 2,检出限为2.78×10^(-8)mol/L。该方法操作简便,应用于注射液、人血清和尿液中多巴胺含量的检测,其加标回收率为96.4%~103.9%,相对标准偏差为0.31%~1.28%。

In a weak acidic buffer solution,protonated dopamine（DA） combined with the nagetively charged silver nanoparticles （AgNPs） whose surface were wrapped with citrate, causing the aggregation of AgNPs. It could result the increase of the resonance light scattering（RLS） intensity of the system at 442 rim. The increased intensity of RLS at this wavelength was linear with the concentration of DA. Thus a novel RLS method for the determination of dopamine was developed based on the aggregation effect of AgNPs. Under the optimum experimental conditions,the linear range of dopamine was 1.0 × 10-7 -2.5 × 10-5 mol/L,the linear regression equation was AI = 2. 808 × 107C ＋ 8. 15, with the correlation coefficient of 0. 999 2 and the detection limit of 2.78× 10 -s mol/L. This method was simple and was applied to the determination of dopamine in injection, human serum and urine sam- ples with mean recoveries of 96. 4% - 103.9% and relative standard deviations of 0. 31% - 1.28%.