title: Visual detection of copper(II) ions in blood samples by controlling the leaching of protein-capped gold nanoparticles.
abstract: 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).
authors.affiliation: 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.
authors.forename: Yen-Fei
authors.initials: YF
authors.lastname: Lee
authors.forename: Ting-Wei
authors.initials: TW
authors.lastname: Deng
authors.forename: Wei-Jane
authors.initials: WJ
authors.lastname: Chiu
authors.forename: Tsao-Yen
authors.initials: TY
authors.lastname: Wei
authors.forename: Prathik
authors.initials: P
authors.lastname: Roy
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Huang
mesh_terms: D003300:Copper / Q000097:blood*; D006046:Gold / Q000737:chemistry*; D007854:Lead / Q000737:chemistry; D008567:Membranes, Artificial; D008623:Mercaptoethanol / Q000737:chemistry; D053768:Metal Nanoparticles; D012710:Serum Albumin, Bovine / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D012710:Serum Albumin, Bovine; D007854:Lead; D008623:Mercaptoethanol; D006046:Gold; D003300:Copper