title: Papain-directed synthesis of luminescent gold nanoclusters and the sensitive detection of Cu2+.
abstract: Highly fluorescent papain stabilized gold nanoclusters (NCs) have been synthesized through a simple wet chemical route. Papain was used for the first time as an effective capping and reducing agent for these clusters. The optimal conditions for the synthesis of the gold nanoclusters, including the concentrations of papain and NaOH, reaction time and temperature, were investigated. The as-prepared Au clusters show intense red emission at ∼660nm (QY ∼4.3%) and are uniform in size. The clusters are quite stable and the intense red emission remained unchanged at a buffer pH range of 6-12. The fluorescent Au NCs were then used as a label-free probe for the sensitive detection of Cu(2+). A limit of detection of 3nM was obtained. The sensing strategy is also highly selective against the various potential interference ions.
authors: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors: Yang
authors: Y
authors: Chen
authors: Yan
authors: Y
authors: Wang
authors: Chuanxi
authors: C
authors: Wang
authors: Wenying
authors: W
authors: Li
authors: Huipeng
authors: H
authors: Zhou
authors: Huping
authors: H
authors: Jiao
authors: Quan
authors: Q
authors: Lin
authors: Cong
authors: C
authors: Yu
mesh_terms: D002413:Cations, Divalent / Q000032:analysis*; D003300:Copper / Q000032:analysis*; D006046:Gold; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D049449:Luminescence; D053768:Metal Nanoparticles / Q000737:chemistry*; D010206:Papain / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002413:Cations, Divalent; D006046:Gold; D003300:Copper; D010206:Papain