Department of Chemistry & Chemical Engineering, Xi'an University of Arts and Science, No. 168 Taibai South Road, Xi'an 710065, P. R. China.
Chem Biodivers. 2013 Sep;10(9):1597-605. doi: 10.1002/cbdv.201200405.
A novel 1,8-naphthalimide probe 1, bearing two acetic-acid moieties was synthesized. The acetic-acid groups, docked into the sub-domains of casein micelle and bound with tryptophan residues, and the 1,8-naphthalimide chromophore adsorbed on the surface of casein micelle, forming a supermolecule, 1-casein micelle, which exhibited the aggregation-induced synchronous emission (AISE) characters. The effect of pH on the intensity of supermolecule was investigated, and the result indicated that the emission enhancement was mainly due to the 1,8-naphthalimide chromophore aggregated onto the casein micelle. Based on AISE, a novel casein quantification method was developed, which exhibited a good linear range of 0.05-10.0 μg ml(-1) and 0.07-9.5 μg ml(-1) with the detection limits of 2.8 and 3.0 ng ml(-1) . The effects of metal ions and pH on the system of 1-casein micelle were investigated. The proposed method was applied to determine casein in milk samples, and the results were in good agreement with the result of the Biuret method.
一种新型的 1,8-萘酰亚胺探针 1，带有两个乙酸基团。乙酸基团可以插入到酪蛋白胶束的亚结构域中，并与色氨酸残基结合，而 1,8-萘酰亚胺发色团则吸附在酪蛋白胶束的表面，形成超分子，即 1-酪蛋白胶束，表现出聚集诱导同步发射（AISE）的特性。研究了 pH 值对超分子强度的影响，结果表明，发射增强主要是由于 1,8-萘酰亚胺发色团聚集到酪蛋白胶束上。基于 AISE，建立了一种新的酪蛋白定量方法，该方法在 0.05-10.0 μg ml(-1) 和 0.07-9.5 μg ml(-1) 的线性范围内具有良好的线性关系，检测限分别为 2.8 和 3.0 ng ml(-1)。研究了金属离子和 pH 值对 1-酪蛋白胶束体系的影响。该方法被应用于牛奶样品中酪蛋白的测定，结果与比色法的结果吻合良好。
