背景:近年来,环境污染已经引起了全球的广泛关注。其中,重金属污染引起的环境问题对人类健康和生态系统构成严重威胁。汞是一种常见的重金属污染物,毒性大、分布广。过量摄入Hg2+会对神经系统造成永久性和严重的损害,呼吸系统,还有人体内的肾脏.因此,快速、准确地检测Hg2+具有重要意义。
结果:基于PtNi纳米线(NWs)和具有过氧化物酶模拟活性的PtNWs设计了灵敏的Hg2比色传感器。PtNiNW和PtNW催化3,3',5,5'-四甲基联苯胺(TMB)与过氧化氢(H2O2)产生蓝色氧化的TMB(oxTMB)。Pt-Hg的特异性相互作用显著抑制PtNiNW和PtNW纳米酶的过氧化物酶模拟活性,导致较浅的蓝色。值得注意的是,与PtNWs的比活性(SA)(3.31U/mg)相比,PtNiNWs拥有优异的SA(10.43U/mg),这不可避免地导致更宽的线性范围的Hg2+分析(1nM-200μM)和检测下限(0.6748nM)的PtNiNWs为基础的比色传感器,相对于基于PtNWs的比色传感器的线性范围(4nM-5μM)和1.198nM的LOD,远低于美国环境保护局设定的饮用水Hg2+阈值(10nM)。
结论:两种纳米酶比色传感器已成功用于评估复杂河水和自来水中的Hg2。由于操作简单的优点,快速反应,灵敏度高,比色传感器在环境监测中具有广阔的应用前景。
BACKGROUND: In recent years, environmental pollution has attracted widespread global attention. Among them, environmental problems caused by heavy metal pollution pose a serious threat to human health and ecosystems. Mercury is a common heavy metal pollutant with high toxicity and wide distribution. Excessive intake of Hg2+ can cause permanent and severe damage to the nervous system, respiratory system, and kidneys in the human body. Therefore, developing both accurate and fast detection methods for Hg2+ is of great significance.
RESULTS: A sensitive Hg2+ colorimetric sensor is designed based on PtNi nanowires (NWs) and Pt NWs with peroxidase-mimetic activity. PtNi NWs and Pt NWs catalyze the reaction of 3,3\', 5,5\'-tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2) to produce blue oxidized TMB (oxTMB). The specific interaction of Pt-Hg significantly inhibits the peroxidase-mimetic activity of PtNi NW and Pt NW nanozymes, resulting in a lighter blue color. It is worth noting that compared with specific activity (SA) of Pt NWs (3.31 U/mg), PtNi NWs own superior SA (10.43 U/mg), which inevitably leads to a wider linear range of Hg2+ analysis (1 nM-200 μM) and a lower detection limit (0.6748 nM) for PtNi NWs-based colorimetric sensor, versus linear range (4 nM-5 μM) and LOD of 1.198 nM for Pt NWs-based colorimetric sensor, which are far below the Hg2+ threshold (10 nM) for drinking water set by the US Environmental Protection Agency.
CONCLUSIONS: The two nanozyme colorimetric sensors have been successfully used for the evaluation of Hg2+ in complex river water and tap water. Due to the advantages of simple operation, fast response, and high sensitivity, colorimetric sensors have broad application prospects in environmental monitoring.