蛋白质-SDS-罗丹明B体系的共振光散射光谱及其分析应用

研究了阴离子表面活性剂十二烷基硫酸钠(SDS),阳离子染料罗丹明B,与蛋白质相互作用的共振光散射(RLS)光谱及用于蛋白质的测定.实验表明,在pH 4.35的酸性介质中,SDS的共振光散射强度较小,它与蛋白质结合后,共振光散射强度能得到增强,但加入阳离子染料罗丹明B后,共振光散射强度显著增强.在λ=332.0 nm处,ΔIRLS最大,并且增强的共振光散射信号与蛋白质的浓度成正比.据此建立了一种测定蛋白质的新方法,该方法灵敏度高,对HSA的检出限达到1.9 ng/mL,线性范围为0.01～5.0 μg/mL.用于人血清样品中蛋白质的测定,回收率为94.0%～105.5%.     

基于与铁氰化钾和Zn~(2+)作用共振光散射法测定异烟肼

在酸性介质中,异烟肼能将铁氰酸根离子还原成亚铁氰酸根离子,后者与硫酸锌反应生成K2Zn3[Fe(CN)6]2粒子引起体系的共振光散射信号显著增强.在345nm处增强的散射信号强度ΔIRLS与异烟肼的浓度在0.01~1.0μg/mL范围内呈线性关系,据此建立了一种检测异烟肼含量的共振光散射(RLS)分析方法.线性回归方程为ΔIRLS=136.1+4239c(c,μg/mL),相关系数(r)为0.9984,检测限(3σ)为3.8ng/mL.该方法已成功用于异烟肼片剂及血清样品的测定.此外,文中还结合吸收光谱,动态光散射,扫描电子显微镜等表征手段对反应机理和RLS信号强度增强的原因进行了探讨.     

樱桃红共振光散射光谱法测定牛血清白蛋白

研究了以樱桃红为共振光散射探针测定牛血清白蛋白的分析方法。在pH 3.58的BR缓冲溶液中,樱桃红与牛血清白蛋白(BSA)相互作用形成复合物,导致共振光散射(RLS)光谱明显增强,最大RLS峰位于340 nm处。由此建立检测痕量BSA的新方法。在优化实验条件下,RLS强度与BSA浓度的线性范围为1.0～60.0μg/mL,检出限为0.15μg/mL。方法可用于牛尿样品的分析。     

甲基紫与苋菜红相互作用的双波长共振光散射比率光谱研究及其分析应用

应用双波长共振光散射比率法(DW-RLS)研究了甲基紫与苋菜红之间的相互作用.在pH 1.24的乙酸钠-HCl缓冲溶液中,甲基紫和苋菜红本身的共振光散射(RLS)信号均很弱,但是当它们相互作用形成缔合物时,导致RLS信号明显增强并出现新的RLS光谱,适当浓度的Triton X-100存在使结合反应敏化,缔合物最大散射峰位于528 nm,RLS信号强度与苋菜红的浓度呈线性关系.通过测量528 nm处的RLS强度或两个波长处RLS强度比值(I417/I343),可对苋菜红进行定量检测.当溶液中甲基紫的浓度为1.54×10-5 mol/L时,RLS法测定苋菜红的线性范围和检出限分别为0.05～0.50 μg/mL和0.02 μg/mL,而DW-RLS法的线性范围和检出限分别为0.01～0.60 μg/mL和1 ng/mL,与RLS法相比较,DW-RLS法受酸度、离子强度等环境条件影响较小,并且有更宽的线性范围和更低的检出限.     

金纳米微粒作探针共振瑞利散射光谱法测定卡那霉素

在一种含柠檬酸盐的溶液中, 柠檬酸根阴离子自组装于带正电荷的金纳米微粒表面, 使金纳米微粒成为一种被柠檬酸根包裹的带负电荷的超分子化合物. 在pH 4.4～6.8的弱酸性介质中, 它可与质子化的卡那霉素(KANA)阳离子借静电引力、疏水作用力结合, 形成粒径更大的聚集体(平均粒径从12增至20 nm), 这种聚集体的形成在引起金纳米的等离子体吸收带明显红移(Δλ＝102 nm)的同时, 共振瑞利散射(RRS)显著增强并且倍频散射(FDS)和二级散射(SOS)等共振非线性散射也有较大的增强, 最大散射峰分别位于280 nm (RRS), 310 nm (FDS)和480 nm (SOS)处. 在适当条件下, 散射强度(ΔI)与卡那霉素的浓度成正比, 其中RRS法灵敏度最高, 因此金纳米微粒可作为测定卡那霉素的高灵敏RRS探针, 它对卡那霉素的检出限为10.52 ng•mL^－1, 方法有较好的选择性, 可用于血液中卡那霉素的测定, 文中还讨论了有关反应机理和RRS增强的原因.     

木质素桃红与蛋白质作用的共振光散射研究

研究了木质素桃红与蛋白质结合的共振光散射光谱. 实验结果表明, 在pH 2.56的酸性介质中, 木质素桃红与蛋白质发生静电作用产生以282.0、 346.0、 420.0 nm以及570.0 nm为特征峰的共振光散射（RLS）增强光谱. 在570.0 nm波长光激发下, 蛋白质的质量浓度与增强共振光散射强度ΔIRLS呈线性关系, 对BSA和HSA的检出限分别为39.0和22.3 ng/mL. 方法已用于尿样中总蛋白质分析.     

痕量甲胎蛋白的免疫纳米金催化-氧化亚铜微粒共振散射光谱分析

用粒径15 nm 的纳米金标记单克隆羊抗人甲胎蛋白(GAFP), 制备了甲胎蛋白(AFP)的免疫纳米金探针(AuGAFP). 纳米金及AuGAFP均对葡萄糖还原铜(Ⅱ)生成Cu₂O微粒这一慢反应具有较强的催化作用, Cu₂O微粒在620 nm处产生1个较强的共振散射峰. 将AFP-AuGAFP免疫反应与离心分离技术结合, 建立了超痕量AFP的免疫纳米金催化-Cu₂O微粒共振散射光谱新方法. 随着AFP浓度的增大, AFP-AuGAFP免疫复合物微粒增多, 离心液中AuGAFP浓度降低, 620 nm处的共振散射光强度I_{620 nm}线性降低, 其降低值ΔI_RS与AFP质量浓度ρ(AFP)在0.10～16.0 ng/mL范围内呈现良好的线性关系, 其回归方程为ΔI_RS=4.27ρ(AFP)+1.28, 检出限为0.05 ng/mL. 本方法所用试剂易得, 反应易控制, 灵敏度高, 选择性好, 用于定量分析人血清中的AFP, 结果令人满意.     

钴-TAN-阴离子表面活性剂体系的共振瑞利散射及其分析应用

研究了Co2 与1-(2-噻唑偶氮)-2-萘酚(TAN)、十二烷基苯磺酸钠(SD-BS)作用的共振瑞利散射光谱,在pH 8.0的BR缓冲溶液中,Co2 的加入导致体系共振光散射的增强,其增强强度与Co2 的质量浓度呈线性关系,据此建立了一种测定Co2 的共振光散射法。该法的线性范围为0~600 ng/mL,相关系数为r=0.9990,检出限为2.25 ng/mL。将该法用于人发、茶叶、维生素B12中Co2 的测定,加标回收率为99.83%~105.4%。     

金纳米微粒作探针共振瑞利散射光谱法测定亚甲蓝

在pH为6.5~9.5的中性或弱碱性介质中, 金纳米微粒可与亚甲蓝(MB)阳离子靠静电引力及疏水作用力结合, 形成粒径较大的聚集体(平均粒径从12 nm增至20 nm), 这种聚集体的形成导致共振瑞利散射(RRS)强度显著增强, 最大散射峰位于371 nm. 在适当条件下, 散射强度(ΔI)与亚甲蓝浓度成正比. 该法具有高灵敏度, 将金纳米微粒作为测定亚甲蓝的高灵敏RRS探针, 对亚甲蓝的检出限为21.17 ng/mL, 该法简便， 快速， 且有较好的选择性, 可用于血液中亚甲蓝的测定.     

水溶性苯胺蓝与十六烷基三甲基溴化铵作用的共振光散射研究

在p H 1.81的缓冲介质中,水溶性苯胺蓝与十六烷基三甲基溴化铵作用并形成离子缔合物,产生以383 nm为特征峰的共振光散射(RLS)增强信号。其RLS增强程度与水溶性苯胺蓝浓度成线性关系,检出限和线性范围分别为1.28 nmol/L和0.013~54.0μmol/L,据此建立了痕量水溶性苯胺蓝的共振光散射分析方法。     

Resonance light scattering spectroscopy study of interaction between gold colloid and thiamazole and its analytical application

In this paper, we used resonance light scattering (RLS) spectroscopy to study the interaction between thiol-containing pharmaceutical-thiamazole and gold colloid. At pH 5.2, the resonance light scattering spectrum of gold nanoparticles has a maximum peak at 555 nm and the RLS intensity is enhanced by trace amount of thiamazole due to the interaction between thiamazole and gold colloid. The binding of colloidal gold to thiamazole results in ligand-induced aggregation of colloidal gold, which was characterized by RLS spectrum, ultraviolet-visible (UV-Vis) spectrum, and transmission electron microscopy (TEM). Based upon the study, we proposed a highly sensitive, gold colloid-based assay using RLS spectrum to detect pharmaceuticals for the first time. The mechanism of binding interaction between Au colloid and thiamazole was also discussed.     

Preparation and Characterization of Heparin‐Stabilized Gold Nanoparticles

A simple method for preparing gold nanoparticles in aqueous solution has been developed by using glycosaminoglycan‐heparin as reducing and stabilizing agent and HAuCl₄ as precursor. The obtained gold nanoparticles were characterized by UV‐vis spectroscopy, resonance light scattering spectroscopy (RLS), transmission electron microscopy (TEM) and electrophoresis technology. The influence of reactant concentration for the preparation of gold nanoparticles was investigated. The results indicated that the gold nanoparticles carried negative charges in the aqueous solution and the size and shape of the gold nanoparticles could be controlled by changing the concentration of the heparin. Moreover, the gold nanoparticles obtained with relatively high concentration of heparin were very stable and had relative narrow size distribution.     

Resonance light scattering properties of Eu3+ in gold colloid

Gold colloidal containing rare-earth ions Eu3+ were prepared at room temperature. Fluorescence spectra and resonance light scattering (RLS) spectra of Eu3+ ions and gold colloid containing Eu3+ were measured. For solution containing Eu3+, RLS features show two peaks at the edges of the visible light wavelength region. The short wavelength peak takes place at about 400 nm and the longer wavelength peak is the corresponding 1/2 fraction frequency RLS peak, which takes place at about 780 nm. When gold colloids were added to the solution containing Eu3+, both these two RLS peaks were enhanced. We believe that the energies, which are absorbed by the surface plasmon resonance in the gold nanoparticles, are efficiently transferred into the Eu3+ ions to cause the increased scattering.     

Determination of DNA based on localized surface plasmon resonance light scattering using unmodified gold bipyramids

The DNA was determined based on resonance light scattering (RLS) spectrometry and the localized surface plasmon resonance. The gold bipyramids were used as the probes and synthesized by a seed-mediated method. Cetyltrimethylammonium bromide was used as stabilizing agent. DNA can be bound to the gold bipyramids due to electrostatic interaction and aggregates, which results in a strong enhancement of the RLS intensity. Under the optimal conditions, the intensity of RLS is directly proportional to the concentration of DNA in the range from 0.1 to 2.0 μg mL(-1).     

Sensitive and selective detection of glutathione based on resonance light scattering using sensitive gold nanoparticles as colorimetric probes

In this paper, we reported the development of a highly sensitive and selective resonance light scattering (RLS) technique for glutathione using gold nanoparticle probes. The assay relies upon the distance-dependent optical properties of gold nanoparticles, the self-assembly of glutathione on gold nanoparticles, and the interaction of a 2 : 1 glutathione-Cu(2+) complex. In the presence of Cu(2+), glutathione could rapidly induce the aggregation of gold nanoparticles, thereby resulting in greatly enhanced RLS intensity and red-to-blue (or purple) color change. The concentration of glutathione can be determined by the naked eye or a fluorescence spectrometer. Under the optical conditions, the detection of glutathione can be finished within 20 min, and the detection limit of 10 nM can be reached. The concentration range of the probe is 40-280 nM. The proposed method holds a specific selectivity toward glutathione and it is applied to the detection of glutathione in human serum with satisfactory results. In addition, the assay shows great potential application for disease-associated biomarkers, and it will meet the great demand for amino acid determination in fields such as food processing, biochemistry, pharmaceutical, and clinical analysis.     

Comment on "Multimodal coupling of optical transitions and plasmonic oscillations in rhodamine B modified gold nanoparticles" by M. Stobiecka and M. Hepel, Phys. Chem. Chem. Phys. 2011, 13, 1131

An article recently published in this journal claimed that a resonance enhanced light scattering (RELS) peak for 22 nm gold nanoparticles was observed at 653 nm, which was about 130 nm higher than the surface plasmon resonance maximum. They also claimed to observe RELS from dilute solutions of Rhodamine B, under conditions where it is expected to be in its monomeric form. This comment shows that the position of the RELS peak for the gold nanoparticles is an artefact of measurement and the RELS from Rhodamine B is simply fluorescence. These findings are likely to have a significant impact on the interpretation of the results in terms of interactions of dyes with gold nanoparticles as well as aggregation of gold nanoparticles, which has been reported elsewhere by the same authors.     

Studying the interaction of carbohydrate-protein on the dendrimer-modified solid support by microarray-based plasmon resonance light scattering assay

Here, a three-dimensional (3D) carbohydrate microarray-based plasmon resonance light scattering (RLS) assay has been established for studying carbohydrate-lectin binding with high selectivity. The 3D carbohydrate microarray is fabricated by immobilizing amino-modified carbohydrates on the home-made fourth-generation (G4) NH(2)-terminated poly(amidoamine) dendrimers (PAMAM)-modified substrate. After marking the carbohydrate-lectin binding events by 13 nm peptide-stabilized gold nanoparticles through the biotin-avidin reaction, the 3D microarray can be directly detected by the RLS scanner without the conventional silver enhancement step. The well defined recognition systems: three monosaccharides (Man-α, Glc-α and Gal-β) with two lectins (Con A and RCA 120), have been chosen here to establish the RLS assay, respectively. Quantitative determination of the surface dissociation constants (K(D,surf)) for surface carbohydrates and lectins has been achieved. In addition, inhibition values (i.e. the inhibition constants (K(i)) and the concentrations of inhibitors required to produce 50% inhibition (IC(50))) for inhibitors in solution are also demonstrated by the saccharide competing assays.     

The Interaction between Propranolol and Gold Nanoparticles and its Analytical Application

The addition of propranolol induced the aggregation of gold nanoparticles, and increased Rayleigh light scattering (RLS) intensity greatly. The interaction between them was studied by RLS spectrum, UV-Vis spectrum and transmission electron microscopy (TEM). Based on these results, a novel method was proposed for propranolol assay. With the combination of solid phase microextraction (SPME), the proposed method was successfully applied to determine propranolol in urine.     

Determination of a cationic surfactant with naphthalene black 12B by the resonance light scattering technique

A new determination method for a cationic surfactant, zephiramine (Zeph), was developed with resonance light scattering (RLS) technique, based on the interaction of naphthalene black 12B with Zeph. The resonance light scattering (RLS) and UV characteristics of interaction between naphthalene black 12B and Zeph were studied. The RLS intensity of naphthalene black 12B at 363 nm was greatly enhanced in the presence of Zeph at pH 6.0. The enhanced RLS is proportional to the concentration of Zeph in the range of 3.20 x 10(-7) - 1.44 x 10(-5) mol L(-1). The limit of detection was 8.8 x 10(-8) mol L(-1). The proposed method was applied to the determination of Zeph in synthetic and spiked water samples with the recovery of 96.2-104% and RSD of 1.1-2.5%.     

聚苯乙烯-丙烯酸纳米粒子的制备及共振光散射性质

聚苯乙烯-丙烯酸纳米粒子的制备及共振光散射性质;无皂乳液聚合;超声辐射