Institute of Bioscience and Biotechnology and Center of Excellence for Marine Bioenvironment and Biotechnology, National Taiwan Ocean University, 2, Pei-Ning Road, Keelung, 20224, Taiwan.
Analyst. 2012 Apr 21;137(8):1800-6. doi: 10.1039/c2an16270a. Epub 2012 Mar 1.
We have developed a simple, low-cost, paper-based probe for the selective colorimetric detection of copper ions (Cu(2+)) in aqueous solutions. The bovine serum albumin (BSA)-modified 13.3-nm Au nanoparticle (BSA-Au NP) probe was designed to detect Cu(2+) ions using lead ions (Pb(2+)) and 2-mercaptoethanol (2-ME) as leaching agents in a glycine-NaOH (pH 12.0) solution. In addition, a nitrocellulose membrane (NCM) was used to trap the BSA-Au NPs, leading to the preparation of a nanocomposite film consisting of a BSA-Au NP-decorated membrane (BSA-Au NPs/NCM). The BSA-Au NPs probe operates on the principle that Cu deposition on the surface of the BSA-Au NPs inhibits their leaching ability, which is accelerated by Pb(2+) ions in the presence of 2-ME. Under optimal solution conditions (5 mM glycine-NaOH (pH 12.0), Pb(2+) (50 μM), and 2-ME (1.0 M)), the Pb(2+)/2-ME-BSA-Au NPs/NCM enabled the detection of Cu(2+) at nanomolar concentrations in aqueous solutions by the naked eye with high selectivity (at least 100-fold over other metal ions). In addition, this cost-effective probe allowed for the rapid and simple determination of Cu(2+) ions in not only natural water samples but also in a complex biological sample (in this case, blood sample).
我们开发了一种简单、低成本的基于纸张的探针，用于选择性比色检测水溶液中的铜离子（Cu(2+)）。牛血清白蛋白（BSA）修饰的 13.3nm 金纳米粒子（BSA-Au NP）探针被设计用于使用铅离子（Pb(2+)）和 2-巯基乙醇（2-ME）作为浸出剂在甘氨酸-NaOH（pH 12.0）溶液中检测 Cu(2+)离子。此外，硝化纤维素膜（NCM）用于捕获 BSA-Au NPs，从而制备由 BSA-Au NP 修饰的膜（BSA-Au NPs/NCM）组成的纳米复合材料膜。BSA-Au NPs 探针的工作原理是 Cu 在 BSA-Au NPs 表面的沉积抑制了其浸出能力，而在存在 2-ME 的情况下，Pb(2+)离子加速了这一过程。在最佳溶液条件下（5 mM 甘氨酸-NaOH（pH 12.0）、Pb(2+)（50 μM）和 2-ME（1.0 M）），Pb(2+)/2-ME-BSA-Au NPs/NCM 允许通过肉眼以高选择性（至少比其他金属离子高 100 倍）在纳米摩尔浓度下检测水溶液中的 Cu(2+)。此外，这种具有成本效益的探针不仅允许快速简单地测定天然水样中的 Cu(2+)离子，而且还可以测定复杂的生物样品（在这种情况下为血液样品）中的 Cu(2+)离子。
