A sensitive and selective assay of proteins is proposed based on measuring the total internal-reflected resonance light scattering(TIR-RLS) signals produced on the water/tetrachloromethane(H_2O/CCl_4) interface. In an...A sensitive and selective assay of proteins is proposed based on measuring the total internal-reflected resonance light scattering(TIR-RLS) signals produced on the water/tetrachloromethane(H_2O/CCl_4) interface. In an aqueous medium with pH value in the range of 3.29—3.78, electrostatic attraction occurs between the negatively charged Evans Blue(EB) and positively charged proteins, forming hydrophobic ion associates and resulting in EB-protein adsorption on H_2O/CCl_4 interface. The presence of cetyltrimethylammonium bromide prompts this adsorption, resulting in strongly enhanced TIR-RLS signals. The intensity of the enhanced TIR-RLS at 360—370 nm was found to be proportional to the concentration of proteins. For bovine serum albumin and human serum albumin, the linear range of detection is 0.07—1.2 μg/mL and the limits of detection are 6.68 and 6.30 ng/mL(3σ), respectively, while for lysozyme, the linear range of detection is 0.06—1.0 μg/mL and the limit of detection is 6.0 ng/mL(3σ). The content of the total albumin in a human urine sample could be directly determined by using the standard addition method with a percent recovery of 97.6%—104.1%, and the RSD ranging from 1.9% to 4.2%.展开更多
以十六烷基三甲基溴化铵(CTMAB)为稳定剂使得硫酸钡比浊法的试剂配制与测定过程变得十分简便,但在实际使用过程中发现测定结果的线性程度较差,测试结果不稳定。分析原因后发现,目前的测定方法对于不同浓度的待测液采取的静置时间是一致...以十六烷基三甲基溴化铵(CTMAB)为稳定剂使得硫酸钡比浊法的试剂配制与测定过程变得十分简便,但在实际使用过程中发现测定结果的线性程度较差,测试结果不稳定。分析原因后发现,目前的测定方法对于不同浓度的待测液采取的静置时间是一致的,而CTMAB保持溶液吸光度稳定的时间特性有较大的区别,导致测定结果出现较大偏差。除此之外,所使用的单色光波长、稳定剂CTMAB、沉淀剂BaCl2、盐酸加入量均对测定结果有一定的影响。实验结果表明,在单色光波长为700 nm,CTMAB、Ba Cl2、盐酸加入量分别为3、5、3 m L,对不同浓度待测液采用不同静置时长时,以CTMAB为稳定剂的硫酸钡比浊法测定结果的线性度最佳。展开更多
The fluorescence enhancement mechanism of Dy3＋-Gd3＋- SSA-CTMAB system was studied by the resonance light scattering and fluorescence spectrum. In this paper, the influencing factors including the concentration of Gd...The fluorescence enhancement mechanism of Dy3＋-Gd3＋- SSA-CTMAB system was studied by the resonance light scattering and fluorescence spectrum. In this paper, the influencing factors including the concentration of Gd3＋, ligands, pH value as well as surfactants were studied. As a result, the optimal experimental conditions were obtained. The existence of molecule congeries was proved by scattering-light spectrum.展开更多
文摘A sensitive and selective assay of proteins is proposed based on measuring the total internal-reflected resonance light scattering(TIR-RLS) signals produced on the water/tetrachloromethane(H_2O/CCl_4) interface. In an aqueous medium with pH value in the range of 3.29—3.78, electrostatic attraction occurs between the negatively charged Evans Blue(EB) and positively charged proteins, forming hydrophobic ion associates and resulting in EB-protein adsorption on H_2O/CCl_4 interface. The presence of cetyltrimethylammonium bromide prompts this adsorption, resulting in strongly enhanced TIR-RLS signals. The intensity of the enhanced TIR-RLS at 360—370 nm was found to be proportional to the concentration of proteins. For bovine serum albumin and human serum albumin, the linear range of detection is 0.07—1.2 μg/mL and the limits of detection are 6.68 and 6.30 ng/mL(3σ), respectively, while for lysozyme, the linear range of detection is 0.06—1.0 μg/mL and the limit of detection is 6.0 ng/mL(3σ). The content of the total albumin in a human urine sample could be directly determined by using the standard addition method with a percent recovery of 97.6%—104.1%, and the RSD ranging from 1.9% to 4.2%.
文摘以十六烷基三甲基溴化铵(CTMAB)为稳定剂使得硫酸钡比浊法的试剂配制与测定过程变得十分简便,但在实际使用过程中发现测定结果的线性程度较差,测试结果不稳定。分析原因后发现,目前的测定方法对于不同浓度的待测液采取的静置时间是一致的,而CTMAB保持溶液吸光度稳定的时间特性有较大的区别,导致测定结果出现较大偏差。除此之外,所使用的单色光波长、稳定剂CTMAB、沉淀剂BaCl2、盐酸加入量均对测定结果有一定的影响。实验结果表明,在单色光波长为700 nm,CTMAB、Ba Cl2、盐酸加入量分别为3、5、3 m L,对不同浓度待测液采用不同静置时长时,以CTMAB为稳定剂的硫酸钡比浊法测定结果的线性度最佳。
基金Acknowledgement： The authors are thankful to the Natural Science Foundation of Shandong Province for its financial support （No. J06105） and the Youth Foundation of ghandong Agricultural University.
文摘The fluorescence enhancement mechanism of Dy3＋-Gd3＋- SSA-CTMAB system was studied by the resonance light scattering and fluorescence spectrum. In this paper, the influencing factors including the concentration of Gd3＋, ligands, pH value as well as surfactants were studied. As a result, the optimal experimental conditions were obtained. The existence of molecule congeries was proved by scattering-light spectrum.
