High-Sensitivity Immunoassay with Surface Plasmon Field-Enhanced Fluorescence Spectroscopy Using a Plastic Sensor Chip: Application to Quantitative Analysis of Total Prostate-Specific Antigen and GalNAcβ1–4GlcNAc-Linked Prostate-Specific Antigen for Prostate Cancer Diagnosis

• Published in: Analytical chemistry (Washington) Vol. 87; no. 3; pp. 1797 - 1803
• Main Authors: Kaya, Takatoshi, Kaneko, Tomonori, Kojima, Shun, Nakamura, Yukito, Ide, Youichi, Ishida, Kenji, Suda, Yoshihiko, Yamashita, Katsuko
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 03-02-2015
• Subjects: Equipment Design; Humans; Immunoassay - instrumentation; Lactose - analogs & derivatives; Lactose - analysis; Lactose - blood; Limit of Detection; Male; Prostate-Specific Antigen - analysis; Prostate-Specific Antigen - blood; Prostatic Neoplasms - blood; Prostatic Neoplasms - diagnosis; Spectrometry, Fluorescence - instrumentation
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac503735e

A high-sensitivity immunoassay system with surface plasmon field-enhanced fluorescence spectrometry (SPFS) was constructed using a plastic sensor chip and then applied to the detection of total prostate-specific antigen (total PSA) and GalNAcβ1–4GlcNAc-linked prostate-specific antigen (LacdiNAc-PSA) in serum, to discriminate between prostate cancer (PC) and benign prostate hyperplasia (BPH). By using this automated SPFS immunoassay, the detection limit for total PSA in serum was as low as 0.04 pg/mL, and the dynamic range was estimated to be at least five digits. A two-step sandwich SPFS immunoassay for LacdiNAc-PSA was constructed using both the anti-PSA IgG antibody to capture PSA and Wisteria floribunda agglutinin (WFA) for the detection of LacdiNAc. The results of the LacdiNAc-PSA immunoassay with SPFS showed that the assay had a sensitivity of 20.0 pg/mL and permitted the specific distinction between PC and BPH within the PSA gray zone. These results suggested that high-sensitivity automated SPFS immunoassay systems might become a powerful tool for the diagnosis of PC and other diseases.