title: Urchin-like (gold core)@(platinum shell) nanohybrids: A highly efficient peroxidase-mimetic system for in situ amplified colorimetric immunoassay.
abstract: The development of signal-amplified colorimetric immunoassay relies on the design of highly efficient signal-transduction tags. One promising route is to exploit a novel enzyme mimetic system as the signal label. Herein, we report that urchin-like (gold core)@(platinum shell) nanohybrids (Au@PtNHs) can be utilized as a highly efficient peroxidase mimetic system for in situ amplified colorimetric immunoassay of prostate-specific antigen (PSA, one kind of tumor marker). Initially, urchin-like Au@PtNHs were discovered to outperform horseradish peroxidase (HRP) by a vast margin in terms of the turnover number toward hydrogen peroxide (H2O2)-3,3',5,5'-tetramethylbenzidine (TMB) system and the stability against high temperatures and HRP inhibitors. Based on this discovery, the assay was simply carried out on a capture antibody-immobilized microplate by using the Au@PtNH-labeled detection antibody as a signal-transduction tag with a sandwich-type assay mode. The colorimetric signal stemmed from the labeled Au@PtNHs toward catalytic oxidation of TMB-H2O2 system. Experimental results indicated that the Au@PtNH-based colorimetric immunoassay could display a good colorimetric response toward PSA in the dynamic working range of 5-500 pg mL(-1) with a low detection limit of 2.9 pg mL(-1). Meanwhile, the developed immunoassay exhibited good precision and reproducibility, high specificity and acceptable accuracy for the detection of clinical serum samples. These results open up a new horizon for the development of highly sensitive, highly stable and inexpensive non-enzyme immunoassay platforms as an alternative to conventional enzyme-based immunoassay platforms.
authors: Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & Ministry of Education), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350116, PR China.
authors: Zhuangqiang
authors: Z
authors: Gao
authors: Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & Ministry of Education), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350116, PR China.
authors: Mingdi
authors: M
authors: Xu
authors: Institute of Environmental and Analytical Science, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, PR China. Electronic address: minghua.luhnu@gmail.com.
authors: Minghua
authors: M
authors: Lu
authors: Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & Ministry of Education), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350116, PR China.
authors: Guonan
authors: G
authors: Chen
authors: Key Laboratory of Analysis and Detection for Food Safety (Fujian Province & Ministry of Education), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350116, PR China. Electronic address: dianping.tang@fzu.edu.cn.
authors: Dianping
authors: D
authors: Tang
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis; D003124:Colorimetry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D058608:Nanopores / Q000648:ultrastructure; D009195:Peroxidase / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D017430:Prostate-Specific Antigen / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D010984:Platinum; D006046:Gold; D009195:Peroxidase; D017430:Prostate-Specific Antigen
keywords: Colorimetric immunoassay; Nanocatalysts; Peroxidase-mimics; Prostate-specific antigen; Urchin-like (gold core)@(platinum shell) nanohybrids