title: Development of a novel method for determination of mercury based on its inhibitory effect on horseradish peroxidase activity followed by monitoring the surface plasmon resonance peak of gold nanoparticles.
abstract: A highly sensitive and simple indirect spectrophotometric method has been developed for the determination of trace amounts of inorganic mercury (Hg(2+)) in aqueous media. The method is based on the inhibitory effect of Hg(2+) on the activity of horseradish peroxidase (HRP) in the oxidation of ascorbic acid by hydrogen peroxide followed by the reduction of Au(3+) to Au-NPs by unreacted ascorbic acid and the measurement of the absorbance of localized surface plasmon resonance (LSPR) peak of gold nanoparticles (at 530 nm) which is directly proportional to the concentration of Hg(2+). Under the optimum conditions, the calibration curve was linear in the concentration range of 1-220 ng mL(-1). Limits of detection (LOD) and quantification (LOQ) were 0.2 and 0.7 ng mL(-1), respectively and the relative standard deviation at 100 ng mL(-1) level of Hg(2+) was 2.6%. The method was successfully applied to the determination of mercury in different water samples.
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, 89195-741 Yazd, Iran.
authors.forename: Javad
authors.initials: J
authors.lastname: Khodaveisi
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, 89195-741 Yazd, Iran.
authors.forename: Ali Mohammad Haji
authors.initials: AM
authors.lastname: Shabani
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, 89195-741 Yazd, Iran. Electronic address: sdadfarnia@yazd.ac.ir.
authors.forename: Shayessteh
authors.initials: S
authors.lastname: Dadfarnia
authors.affiliation: Department of Chemistry, Faculty of Science, Vali-e-Asr University, Rafsanjan, Iran.
authors.forename: Masoud Rohani
authors.initials: MR
authors.lastname: Moghadam
authors.affiliation: Department of Chemistry, Sharif University of Technology, Tehran 11155-9516, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Hormozi-Nezhad
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D002138:Calibration; D002412:Cations; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D020349:Surface Plasmon Resonance / Q000379:methods*; D013501:Surface-Active Agents / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D002412:Cations; D013501:Surface-Active Agents; D014867:Water; D006046:Gold; D006735:Horseradish Peroxidase; D008628:Mercury; D001205:Ascorbic Acid
keywords: Gold nanoparticle; Horseradish peroxidase; Inorganic mercury (Hg(2+)); Localized surface plasmon resonance band