title: Colorimetric detection of urea, urease, and urease inhibitor based on the peroxidase-like activity of gold nanoparticles.
abstract: Herein, we reported for the first time that gold nanoparticles-catalyzed 3,3',5,5'-tetramethylbenzidine-H2O2 system can serve as an ultrasensitive colorimetric pH indicator. Gold nanoparticles acted as a catalyst and imitated the function of horseradish peroxidase. The absorbance at 450 nm of the yellow-color product in the catalytic reaction exhibited a linear fashion over the pH range of 6.40-6.60. On the basis of this property, we constructed a novel sensing platform for the determination of urea, urease, and urease inhibitor. The limit of detection for urea and urease was 5 μM and 1.8 U/L, respectively. The half-maximal inhibition value IC50 of acetohydroxamic acid was found to be 0.05 mM. Urea in human urine and urease in soil were detected with satisfied results.
authors.affiliation: Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou, 350004, China; Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical Univeristy, Fuzhou, 350004, China.
authors.forename: Hao-Hua
authors.initials: HH
authors.lastname: Deng
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Xiamen University, Xiamen, 361003, China.
authors.forename: Guo-Lin
authors.initials: GL
authors.lastname: Hong
authors.affiliation: Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou, 350004, China; Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical Univeristy, Fuzhou, 350004, China.
authors.forename: Feng-Lin
authors.initials: FL
authors.lastname: Lin
authors.affiliation: Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou, 350004, China; Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical Univeristy, Fuzhou, 350004, China.
authors.forename: Ai-Lin
authors.initials: AL
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China.
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Xia
authors.affiliation: Department of Pharmaceutical Analysis, Fujian Medical University, Fuzhou, 350004, China; Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical Univeristy, Fuzhou, 350004, China. Electronic address: chenandhu@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D003124:Colorimetry / Q000379:methods*; D004791:Enzyme Inhibitors / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014508:Urea / Q000032:analysis*; D014510:Urease / Q000032:analysis* / Q000037:antagonists & inhibitors
chemical_list: D004791:Enzyme Inhibitors; D006046:Gold; D014508:Urea; D014510:Urease
keywords: Acetohydroxamic acid; Gold nanoparticles; Peroxidase-like activity; Urea; Urease