title: L-cysteine protected copper nanoparticles as colorimetric sensor for mercuric ions.
abstract: This report demonstrates a novel, simple and efficient protocol for the synthesis of copper nanoparticles in aqueous solution using L-cysteine as capping or protecting agent. UV-visible (UV-vis) spectroscopy was employed to monitor the LSPR band of L-cysteine functionalized copper nanoparticles (Cyst-Cu NPs) based on optimizing various reaction parameters. Fourier Transform Infrared (FTIR) spectroscopy provided information about the surface interaction between L-cysteine and Cu NPs. Transmission Electron Microscopy (TEM) confirmed the formation of fine spherical, uniformly distributed Cyst-Cu NPs with average size of 34 ± 2.1 nm. X-ray diffractometry (XRD) illustrated the formation of pure metallic phase crystalline Cyst-Cu NPs. As prepared Cyst-Cu NPs were tested as colorimetric sensor for determining mercuric (Hg(2+)) ions in an aqueous system. Cyst-Cu NPs demonstrated very sensitive and selective colorimetric detection of Hg(2+) ions in the range of 0.5 × 10(-6)-3.5 × 10(-6) mol L(-1) based on decrease in LSPR intensity as monitored by a UV-vis spectrophotometer. The developed sensor is simple, economic compared to those based on precious metal nanoparticles and sensitive to detect Hg(2+) ions with detection limit down to 4.3 × 10(-8) mol L(-1). The sensor developed in this work has a high potential for rapid and on-site detection of Hg(2+) ions. The sensor was successfully applied for assessment of Hg(2+) ions in real water samples collected from various locations of the Sindh River.
authors.affiliation: National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 Pakistan. Electronic address: raziumsoomro@gmail.com.
authors.forename: Razium A
authors.initials: RA
authors.lastname: Soomro
authors.affiliation: Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Ayman
authors.initials: A
authors.lastname: Nafady
authors.affiliation: National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 Pakistan.
authors.lastname: Sirajuddin
authors.affiliation: National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 Pakistan.
authors.forename: Najma
authors.initials: N
authors.lastname: Memon
authors.affiliation: National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 Pakistan.
authors.forename: Tufail H
authors.initials: TH
authors.lastname: Sherazi
authors.affiliation: National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 Pakistan.
authors.forename: Nazar H
authors.initials: NH
authors.lastname: Kalwar
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D003300:Copper / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D003300:Copper; D008628:Mercury; D003545:Cysteine
keywords: Amino acid; Colorimetric sensor; Copper nanoparticles; Mercuric ions; l-cysteine