Department of Chemistry, National Changhua University of Education, Changhua, Taiwan.
Analyst. 2011 Mar 7;136(5):863-71. doi: 10.1039/c0an00652a. Epub 2010 Dec 15.
Monitoring the levels of potentially toxic metal (PTM) ions (e.g., Hg(2+), Pb(2+), Cu(2+)) in aquatic ecosystems is important because these ions can have severe effects on human health and the environment. Gold (Au) nanomaterials are attractive sensing materials because of their unique size- and shape-dependent optical properties. This review focuses on optical assays for Hg(2+), Pb(2+), and Cu(2+) ions using functionalized Au nanomaterials. The syntheses of functionalized Au nanomaterials are discussed. We briefly review sensing approaches based on changes in absorbance resulting from metal ion-induced aggregation of Au nanoparticles (NPs) or direct deposition of metal ions onto Au NPs. The super-quenching properties of Au NPs allow them to be employed in 'turn on' and 'turn off' fluorescence approaches for the sensitive and selective detection of Hg(2+), Pb(2+), and Cu(2+) ions. We highlight approaches based on fluorescence quenching through analyte-induced aggregation or the formation of metallophilic complexes of Au nanodots (NDs). We discuss the roles of several factors affecting the selectivity and sensitivity of the nanosensors toward the analytes: the size of the Au nanomaterial, the length and sequence of the DNA or the nature of the thiol, the surface density of the recognition ligand, and the ionic strength and pH of the buffer solution. In addition, we emphasize the potential of using new nanomaterials (e.g., fluorescent silver nanoclusters) for the detection of PTM ions.
监测水生生态系统中潜在有毒金属（PTM）离子（例如 Hg(2+)、Pb(2+)、Cu(2+)）的水平非常重要，因为这些离子会对人类健康和环境造成严重影响。金（Au）纳米材料因其独特的尺寸和形状依赖性光学性质而成为有吸引力的传感材料。本综述重点介绍了使用功能化 Au 纳米材料进行 Hg(2+)、Pb(2+)和 Cu(2+)离子的光学分析。讨论了功能化 Au 纳米材料的合成。我们简要回顾了基于金属离子诱导 Au 纳米粒子（NPs）聚集或金属离子直接沉积在 Au NPs 上引起的吸光度变化的传感方法。Au NPs 的超猝灭特性允许它们在“开启”和“关闭”荧光方法中用于敏感和选择性检测 Hg(2+)、Pb(2+)和 Cu(2+)离子。我们重点介绍了基于通过分析物诱导聚集或 Au 纳米点（NDs）形成金属亲合络合物进行荧光猝灭的方法。我们讨论了影响纳米传感器对分析物选择性和灵敏度的几个因素的作用：Au 纳米材料的尺寸、DNA 的长度和序列或硫醇的性质、识别配体的表面密度以及缓冲溶液的离子强度和 pH 值。此外，我们强调了使用新型纳米材料（例如荧光银纳米团簇）检测 PTM 离子的潜力。
