Quantification of Cancer Biomarkers in Serum Using Scattering-Based Quantitative Single Particle Intensity Measurement with a Dark-Field Microscope

Chung Yan Poon, Lin Wei, Yueling Xu, Bo Chen, Lehui Xiao*, Hung Wing LI

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

54 Citations (Scopus)

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.

Original languageEnglish
Pages (from-to)8849-8856
Number of pages8
JournalAnalytical Chemistry
Volume88
Issue number17
DOIs
Publication statusPublished - 6 Sep 2016

Scopus Subject Areas

  • Analytical Chemistry

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