Abstract

Hg²⁺ toxicity is one of the most common chemical poisonings that occurs mainly from drinking polluted water. In the current work, Phycocyanin (PC) was exploited as a fluorescent sensor for sensitive and selective detection of Hg²⁺ in an aqueous system. PC-Hg²⁺ interaction was monitored using a spectro-fluorometer under different buffered solutions at pH values of 6,7,8,9, or 10 above the isoelectric point of PC (5.18). A remarkable decrease of PC fluorescence intensity was observed under Tris-buffer at pH 6 upon the addition of increasing Hg²⁺ concentrations (1–120 nM). Under the maintained experimental conditions, the current sensor showed a good linear relationship with R² = 0.9971 and a limit of detection as low as 0.7 nM was achieved. In addition, a notable selectivity of Hg²⁺ over other nine heavy metals (Cu^2+, Zn^2+, Pb²⁺, Mg^2+, Mn⁴⁺, Li⁺, Fe^3+, Co²⁺, and Al³⁺) was achieved in the presence of 120 nM of each metal. Moreover, the current fluorescent detection assay was also tested in real samples of pond water, and recoveries as well as relative standard deviations within the acceptable limits were recorded.

摘要

Hg ²⁺毒性是最常见的化学中毒之一，主要由饮用受污染的水引起。在目前的工作中，藻蓝蛋白 (PC) 被用作荧光传感器，用于敏感和选择性检测水性体系中的 Hg ²⁺。PC-Hg ²⁺相互作用使用荧光分光计在不同的缓冲溶液下监测，pH 值高于 PC (5.18) 的等电点 6、7、8、9 或 10。在 pH 6 的 Tris 缓冲液中，随着 Hg ²⁺浓度的增加(1–120 nM) ，PC 荧光强度显着降低。在保持实验条件下，电流传感器与R ²呈现良好的线性关系= 0.9971，达到了低至 0.7 nM 的检测限。此外，Hg ²⁺对其他九种重金属（Cu 2 ^+、 Zn 2 ^+、 Pb ²⁺、Mg 2 ^+、 Mn ⁴⁺、Li ⁺、Fe ^3+、 Co ²⁺和Al ^{3 +} ) 是在每种金属存在 120 nM 的情况下实现的。此外，目前的荧光检测分析还在池塘水的实际样品中进行了测试，并记录了回收率以及可接受限度内的相对标准偏差。