[HgI_4]^(2-)-蛋白质离子缔合物体系共振瑞利散射和共振非线性散射光谱及其分析应用

Resonance Rayleigh Scattering and Resonance Nonlinear Scattering Spectra of Ion-association Complexes of [HgI_4]^(2-)-protein Systems and Their Analytical Applications

在0.0035～0.0045mol/L硫酸介质中,牛血清白蛋白(BSA)、人血清白蛋白(HSA)、卵白蛋白(OVA)和血红蛋白(HGB)等蛋白质以带正电荷的阳离子存在.它们能借助于静电引力和疏水作用力与配阴离子[HgI4]2--反应形成结合产物,此时将引起共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)显著增强,并且出现新的散射光谱.其最大RRS,SOS和FDS波长分别位于390,760和390nm附近.在一定范围内,三种散射增强(△IRRS,△ISOS和△IFDS)与蛋白质浓度成正比,方法具有高灵敏度,三种方法对于不同蛋白质的检出限分别在5.7～15.9ng/mL(RRS),8.2～15.4ng/mL(SOS)和11.2～22.1ng/mL(FDS)之间,均可用于痕量蛋白质的测定.本文研究了[HgI4]2-与蛋白质相互作用对RRS,SOS和FDS光谱特征和强度的影响,考察了适宜的反应条件,并以RRS为例考察了共存物质的影响,表明方法有良好的选择性.据此,利用[HgI4]2-与蛋白质的相互作用发展了一种用共振光散射技术、灵敏度高、简便、快速测定蛋白质的新方法.本方法可用于血清和人尿中总蛋白质的测定.

In 0.0035-0.0045 mol/L H2504 solution, proteins such as bovine serum albumin （BSA）, human serum albumin （HSA）, ovalbumin （OVA） and haemoglobin （HGB） could react with [HgI4]^2- by virtue of electrostatic attraction and hydrophobic force to form ion-association complexes. As a result, the resonance Rayleigh scattering （RRS）, second-order scattering （SOS） and frequency doubling scattering （FDS） intensities were enhanced greatly and the new scattering spectra appeared. The maximum scattering peak at 390 nm is for RRS, 760 nm for SOS and 390 nm for FDS, respectively. The enhanced RRS, SOS and FDS intensities are directly proportional to the concentrations of proteins. The detection limits for the different proteins are 5.7-15.9 ng/mL for the RRS method, 8.2-15.4 ng/mL for the SOS method and 11.2-22.1 ng/mL for the FDS method, respectively. These methods can be used for the determination of trace amounts of proteins. In this work, the effects of interaction of [Hgla]^2-with proteins on RRS, SOS and FDS spectral characteristics, intensities and the optimum conditions have been investigated. Meanwhile, the influences of coexisting sub- stances were tested and the results show that the method exhibits a good selectivity. Based on the above researches, a highly sensitive, simple and rapid method for the determination of trace amounts of proteins by resonance light scattering technique has been developed, which can be applied to the determination of proteins in human urine and serum samples with satisfactory results.