College of Chemistry and Materials Science, Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning 530001, People's Republic of China.
Methods Appl Fluoresc. 2019 Jun 26;7(3):035008. doi: 10.1088/2050-6120/aaff92.
InP/ZnS quantum dot (QD)-based fluorescent probe for directly sensitive and selective detection of horseradish peroxidase (HRP) was reported herein. Fluorescence of InP/ZnS QDs was statically quenched by HRP, due to the ground state complex formation of InP/ZnS QDs with HRP. Such ground state complex formation between InP/ZnS QDs and HRP reduced both the α-helix content and the melting temperature of HRP. Several key factors including InP/ZnS QDs concentration, buffer pH value, ionic strength, reaction temperature, and reaction time those affected the analytical performance of InP/ZnS QDs in HRP determination were investigated thoroughly. Under the optimal conditions, fluorescence intensity of InP/ZnS QDs was linearly decreased with the increasing of HRP concentration during the range of 1.0 × 10 M ∼ 3.0 × 10 M (0.01 U ml ∼ 0.3 U ml) with the detection limit as low as 1.2 × 10 M (1.2 mU ml). The present method showed excellent selectivity for HRP over some amino acids, nucleotides, and common proteins. This method was utilized to detect HRP in synthetic samples successfully.
本文报道了一种基于 InP/ZnS 量子点（QD）的荧光探针，用于直接灵敏和选择性检测辣根过氧化物酶（HRP）。由于 InP/ZnS QD 与 HRP 形成基态配合物，HRP 静态猝灭了 InP/ZnS QD 的荧光。这种 InP/ZnS QD 与 HRP 之间的基态配合物降低了 HRP 的α-螺旋含量和熔点。深入研究了影响 InP/ZnS QD 在 HRP 测定中分析性能的几个关键因素，包括 InP/ZnS QD 浓度、缓冲液 pH 值、离子强度、反应温度和反应时间。在最佳条件下，InP/ZnS QD 的荧光强度随着 HRP 浓度在 1.0×10^-6 M∼3.0×10^-6 M（0.01 U ml∼0.3 U ml）范围内的线性降低，检测限低至 1.2×10^-6 M（1.2 mU ml）。该方法对 HRP 具有优异的选择性，优于一些氨基酸、核苷酸和常见蛋白质。该方法成功用于合成样品中 HRP 的检测。
