School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China.
Analyst. 2020 Apr 7;145(7):2774-2778. doi: 10.1039/d0an00060d. Epub 2020 Feb 25.
A label-free, sensitive, simple and general colorimetric method was reported to monitor S1 nuclease activity based on protamine-assisted aggregation of gold nanoparticles (AuNPs). Here, protamine, a linear polycation, was used as a medium for causing the aggregation of negatively charged AuNPs by electrostatic interactions, resulting in changes in the surface plasmon resonance (SPR) absorption bands as well as the color of AuNPs. Here, the AuNPs were employed as an indicator to detect the level of S1 nuclease in the solution. Substrate DNA could be cleaved into small fragments by the specific S1 nuclease, which effectively prevents the electrostatic interaction between DNA and protamine and thus facilitates the interaction between protamine and AuNPs. The quantitative analysis of S1 nuclease activity can be performed via directly measuring the changes in the absorption spectra of the AuNPs. Using S1 nuclease as a model analyte, the limit of detection was estimated to be 1.0 × 10 U mL. Furthermore, the proposed concept has been successfully applied in S1 nuclease analysis of serum samples, offering an ultrasensitive strategy for the speedy detection of the nuclease activity and providing a new avenue for high-throughput screening of nucleases and drugs with potential inhibition properties.
一种基于鱼精蛋白辅助金纳米粒子（AuNPs）聚集的无标记、灵敏、简单和通用的比色法被报道用于监测 S1 核酸酶活性。在这里，鱼精蛋白是一种线性聚阳离子，用作通过静电相互作用引起带负电荷的 AuNPs 聚集的介质，导致表面等离子体共振（SPR）吸收带以及 AuNPs 的颜色发生变化。在这里，AuNPs 被用作检测溶液中 S1 核酸酶水平的指示剂。底物 DNA 可以被特异性 S1 核酸酶切割成小片段，这有效地阻止了 DNA 和鱼精蛋白之间的静电相互作用，从而促进了鱼精蛋白和 AuNPs 之间的相互作用。通过直接测量 AuNPs 吸收光谱的变化，可以进行 S1 核酸酶活性的定量分析。使用 S1 核酸酶作为模型分析物，检测限估计为 1.0×10 U mL。此外，该概念已成功应用于血清样品中 S1 核酸酶的分析，为核酸酶活性的快速检测提供了一种超灵敏的策略，并为具有潜在抑制特性的核酸酶和药物的高通量筛选提供了新途径。
