Two new cyclic pentacoordinative organotin(IV) complexes, 2,4-dihydroxyacetophenone tribenzyltin(HAPTBT) and 2,4-dihydroxyacetophenone triphenyltin(HAPTPT) were synthesized and used as anion ionophore for PVC membrane electrode. The new electrodes exhibit specificity selectivity for salicylate. The electrode based on HAPTBT as a neutral carrier displays a highly potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in the following order: Sal- > SCN- > I- > NO2- > Br- > Cl- > ClO4- > NO3- > SO42-. The electrode has the advantages of fast response, stability and reproducibility, simplicity. The response mechanism is discussed in view of UV spectroscopy technique. The results show that there are close relationship between the potentiometric response characteristics and structure of organotin(IV) complexes. The electrode was applied to medicine analysis with satisfactory results.
提出了一种基于纳米金标记的阳极溶出伏安免疫分析方法。免疫反应在聚苯乙烯微孔板中以夹心分析模式进行,通过物理吸附将兔抗人免疫球蛋白 A(IgA)抗体固定于微孔板上,与相应抗原 IgA 发生免疫反应后,再通过夹心模式捕获相应的纳米金标记的羊抗人 IgA 抗体,然后再与金标羊抗人 IgA 抗体和金标兔抗羊二抗形成的免疫复合物反应,在微孔板上引入大量的纳米金,将金溶解后,在碳糊电极上用阳极溶出伏安法(ASV)对金离子进行检测,溶出峰电流的大小间接与待分析物 IgA 的浓度成正比。对免疫分析的一些实验条件进行了优化。阳极溶出峰电流与 IgA 的浓度在0.018 mg/L～181 mg/L 范围内呈良好的线性关系,检测下限为10μg/L。将该分析方法应用于人血清中 IgA 浓度的测定,取得了满意结果。
A novel, sensitive anodic stripping volammetric immunoassay was developed based on silver-enhanced immuno-gold label. The immunoreaction was performed in a polystyrene microwell by using the sandwich format. Primary antibodies specific for C-3(complement Ⅲ) were adsorbed passively on the walls of a polystyrene microwell. The C-3 analyte was first captured by the primary antibody and then sandwiched by a secondary colloidal gold-labeled antibody. The addition of the silver enhancement solution results in the precipitation of a large amount of silver on colloidal gold labels due to the catalytic reduction which, after silver metal dissolution in an acidic solution, was determined by anodic stripping voltammetry(ASV) at a glassy-carbon electrode. The influence of some immunoassay conditions upon the anodic stripping peak current was examined and optimized. The anodic stripping peak current depended linearly on the logarithm of C-3 mass concentration over the range of 7.2 ng/mL to 7.33 μg/mL and a detection limit as low as 7ng/mL is achieved. The anodic stripping volammetric immunoassay was applied to the determination of C-3 concentration in human serum with satisfactory results.
A novel electrochemical immunosensor with amplification effect based on the enzyme inhibition of silver deposition was proposed. In this method, the capture antibody was first immobilized onto a gold electrode via a self-assembled layer. After a sandwich immunoreaction, HRP labeled antibody was bound to the gold electrode. The HRP on the electrode inhibited silver deposition when the electrode was incubated in hydroquinone-H2O2 solution and silver ion solution. The linear sweep voltammetry was chosen to detect the deposited silver and the result showed that the peak current was linearly proportional to the content of IgG in the range of 50 to 2500 ng/mL with a detection limit of 35 ng/mL.
