Glutathione-stabilized palladium nanozyme for colorimetric assay of silver(I) ions.
Glutathione-capped Pd nanoparticles with a size of 1.4-3.5 nm are facilely synthesized for peroxidase nanomimetics. The molar ratio of [Na2PdCl4]/[GSH] greatly affects the physicochemical properties including particle sizes, surface charge states and enzymatic activities. The most efficient Pd-based nanozyme, consisting of approximately 57% metallic Pd(0) species with an average diameter of 2.6 nm, exhibits the K(m) value of 0.068 mM toward 3,3',5,5'-tetramethylbenzidine and 156 mM toward hydrogen peroxide. Ag(+) selectively binds to Pd(0) species through metallophilic interactions and induces an apparent aggregation of Pd nanoparticles. This is the first report that Ag(+) significantly inhibits the peroxidase mimicking activity of Pd nanoparticles. A Pd-based nanozyme is employed to explore colorimetric detection of Ag(+) with the limit of detection of 1.2 nM. This developed sensing system is potentially applicable for quantitative detection of Ag(+) in drinking water as well as Ag nanoparticles in aqueous solution.
Key Laboratory for Green Chemical Technology MOE, Tianjin University; Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin 300072, People's Republic of China. liwei@tju.edu.cn.
Yan
Y
Fu
Haixiang
H
Zhang
Shengdong
S
Dai
Xing
X
Zhi
Jinli
J
Zhang
Wei
W
Li
D001560:Benzidines / Q000737:chemistry; D040761:Biomimetic Materials / Q000737:chemistry; D003124:Colorimetry / Q000379:methods*; D005978:Glutathione / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D009195:Peroxidase / Q000378:metabolism; D012834:Silver / Q000032:analysis* / Q000737:chemistry; D014867:Water / Q000737:chemistry
D001560:Benzidines; D014867:Water; C021758:3,3',5,5'-tetramethylbenzidine; D012834:Silver; D010165:Palladium; D006861:Hydrogen Peroxide; D009195:Peroxidase; D005978:Glutathione