title: Quantification of Cancer Biomarkers in Serum Using Scattering-Based Quantitative Single Particle Intensity Measurement with a Dark-Field Microscope.
abstract: In this work, we developed a simple yet robust single particle scattering intensity measurement method for the quantification of cancer-related biomarkers. The design is based on the plasmonic coupling effect between noble metal nanoparticles. First, the primary and secondary antibodies were conjugated onto the surface of 60 nm gold nanoparticles (AuNPs, act as capture probes) and 50 nm silver nanoparticles (AgNPs, act as signal amplification probes) respectively. In the presence of corresponding antigen, a sandwiched immunocomplex was formed, resulting a significantly enhanced scattering intensity in contrast to that of individual probes. By measuring the intensity change of the particles with a dark-field microscope (DFM), the amount of target protein could be accurately quantified. As a proof of concept experiment, quantification of three types of antigens, including carcinoembryonic antigen (CEA), prostate-specific antigen (PSA) and alpha fetoprotein (AFP) by this platform was demonstrated with limit of detection (LOD) of 1.7, 3.3, and 5.9 pM, respectively, with a linear dynamic range of 0 to 300 pM. Furthermore, to elucidate the potential in clinical application, the content of antigens in a serum sample was also quantified directly without additional sample pretreatment. In order to validate the reliability of this method, the measured result was also compared with that obtained by regular enzyme-linked immunosorbent assay (ELISA) kit, showing good consistency between these two data sets. Therefore, owing to the simplicity and accuracy of this method, it could be potentially applied for massive disease screening in clinical assay in the future.
authors: Department of Chemistry, Hong Kong Baptist University , Kowloon Tong, Hong Kong, China.
authors: Chung-Yan
authors: CY
authors: Poon
authors: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University , Changsha, Hunan 410081, China.
authors: Lin
authors: L
authors: Wei
authors: College of Chemistry, Nankai University , Tianjin, 300071, China.
authors: Yueling
authors: Y
authors: Xu
authors: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University , Changsha, Hunan 410081, China.
authors: Bo
authors: B
authors: Chen
authors: Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University , Changsha, Hunan 410081, China.|College of Chemistry, Nankai University , Tianjin, 300071, China.
authors: Lehui
authors: L
authors: Xiao
authors: Department of Chemistry, Hong Kong Baptist University , Kowloon Tong, Hong Kong, China.
authors: Hung-Wing
authors: HW
authors: Li
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D015374:Biosensing Techniques; D002272:Carcinoembryonic Antigen / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry; D008853:Microscopy; D009369:Neoplasms / Q000097:blood*; D017430:Prostate-Specific Antigen / Q000097:blood*; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D019216:Metals, Heavy; D000509:alpha-Fetoproteins; D017430:Prostate-Specific Antigen