Visual detection of copper(n) ions in blood samples by controlling the leaching of protein-capped gold nanoparticles

• Published in: Analyst (London) Vol. 137; no. 8; pp. 1800 - 1806
• Main Authors: LEE, Yen-Fei, DENG, Ting-Wei, CHIU, Wei-Jane, WEI, Tsao-Yen, ROY, Prathik, HUANG, Chih-Ching
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 21.04.2012
• Subjects: Analytical chemistry; Aqueous solutions; Blood; Chemistry; Copper; Copper - blood; Exact sciences and technology; Gold; Gold - chemistry; Indexing in process; Leaching; Lead - chemistry; Membranes, Artificial; Mercaptoethanol - chemistry; Metal Nanoparticles; Nanomaterials; Nanostructure; Serum Albumin, Bovine - chemistry; Spectrometric and optical methods; Water; Fold; Nanoparticle; Metal ion; Colorimetry; Selectivity; Glycine; Probe; Blood; Design; Eye; Cellulose nitrate; pH; Membrane; Nanocomposite; Inhibition; Ungulata; Deposition; Gold; Lead ion; Bovine; Sample; Use; Serum albumin; Concentration; Leaching; Protein; Biological compound; Vertebrata; Mammalia; Copper ion; Preparation; Artiodactyla; Aqueous solution; Detection
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c2an16270a

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).