title: A sensitive and selective colorimetric method for detection of copper ions based on anti-aggregation of unmodified gold nanoparticles.
abstract: A highly sensitive and selective colorimetric method for detection of copper ions, based on anti-aggregation of D-penicillamine (D-PC) induced aggregated gold nanoparticles (AuNPs) was developed. Copper ions can hinder the aggregation of AuNPs induced by D-PC, through formation of mixed-valence complex with D-PC that is a selective copper chelator. In the presence of a fixed amount of D-PC, the aggregation of AuNPs decreases with increasing concentrations of Cu(2+) along with a color change from blue to red in AuNPs solution and an increase in the absorption ratio (A520/A650). Under the optimum experimental conditions (pH 7, [AuNPs] =3.0 nmol L(-1) and [NaCl]=25 mmol L(-1)), a linear calibration curve for Cu(2+) was obtained within the range of 0.05-1.85 µmol L(-1) with a limit of detection (3Sb) of 30 nmol L(-1). Excellent selectivity toward Cu(2+) was observed among various metal ions due to a specific complex formation between Cu(2+) and D-PC. The proposed method has been successfully applied for the detection of Cu(2+) in various real samples.
authors.affiliation: Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran; Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, Iran. Electronic address: hormozi@sharif.edu.
authors.forename: M Reza
authors.initials: MR
authors.lastname: Hormozi-Nezhad
authors.affiliation: Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran; Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, Iran.
authors.forename: Samira
authors.initials: S
authors.lastname: Abbasi-Moayed
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D003124:Colorimetry / Q000379:methods*; D003300:Copper / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D010396:Penicillamine / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification
chemical_list: D002614:Chelating Agents; D007477:Ions; D008670:Metals; D013438:Sulfhydryl Compounds; D014874:Water Pollutants, Chemical; D014867:Water; D012965:Sodium Chloride; D006046:Gold; D003300:Copper; D010396:Penicillamine
keywords: Anti-aggregation; Colorimetric detection; Copper ions; Gold nanoparticle