title: Homogeneous immunoassays by using photon burst counting technique of single gold nanoparticles.
abstract: In this paper, we reported a sensitive single particle method by combining the photon burst counting technique with gold nanoparticles (GNPs) as labeling probes. The photon bursting of single GNPs will be generated in a highly focused laser beam (less than 1 fL) due to the plasmon resonance scattering and Brownian motion of GNPs. We observed an excellent linear relationship between the photon burst counts and the number of particles in GNPs solution. We investigated the statistical behaviors of background noise and photon burst signal of GNPs, and proposed the data processing method based on Gaussian distribution of the background noise. A new homogeneous sandwich immunoassay was developed by using this single particle method. We evaluated the performance of this method by using prostate-specific antigen (PSA) as a model. The linear range of PSA was 1-1000 pmol/L and the detection limit was 0.8 pmol/L. This novel method was successfully used for the direct detection of cancer biomarker PSA in human serum samples. Our results were in good agreement with conventional ELISA assays.
authors.affiliation: School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Lan
authors.affiliation: School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
authors.forename: Jinjie
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
authors.forename: Chaoqing
authors.initials: C
authors.lastname: Dong
authors.affiliation: School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
authors.forename: Xiangyi
authors.initials: X
authors.lastname: Huang
authors.affiliation: School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China. Electronic address: jicunren@sjtu.edu.cn.
authors.forename: Jicun
authors.initials: J
authors.lastname: Ren
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D016022:Case-Control Studies; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay; D018796:Immunoconjugates / Q000737:chemistry; D057230:Limit of Detection; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry; D017785:Photons; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D059629:Signal-To-Noise Ratio; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*
chemical_list: D000911:Antibodies, Monoclonal; D018796:Immunoconjugates; D006046:Gold; D017430:Prostate-Specific Antigen
keywords: Gold nanoparticles (GNPs); Homogeneous sandwich immunoassay; Photon burst counting; Prostate specific antigen (PSA)