Upconversion nanoparticle-assisted single-molecule assay for detecting circulating antigens of aggressive prostate cancer

Yinghui Chen, Olga Shimoni, Guan Huang, Shihui Wen, Jiayan Liao, Hien T. T. Duong, Mahnaz Maddahfar, Qian Peter Su, David Gallego Ortega, Yanling Lu, Douglas H. Campbell, Bradley J. Walsh, Dayong Jin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Sensitive and quantitative detection of molecular biomarkers is crucial for the early diagnosis of diseases like metabolic syndrome and cancer. Here we present a single-molecule sandwich immunoassay by imaging the number of single nanoparticles to diagnose aggressive prostate cancer. Our assay employed the photo-stable upconversion nanoparticles (UCNPs) as labels to detect the four types of circulating antigens in blood circulation, including glypican-1 (GPC-1), leptin, osteopontin (OPN), and vascular endothelial growth factor (VEGF), as their serum concentrations indicate aggressive prostate cancer. Under a wide-field microscope, a single UCNP doped with thousands of lanthanide ions can emit sufficiently bright anti-Stokes' luminescence to become quantitatively detectable. By counting every single streptavidin-functionalized UCNP which specifically labeled on each sandwich immune complex across multiple fields of views, we achieved the Limit of Detection (LOD) of 0.0123 ng/ml, 0.2711 ng/ml, 0.1238 ng/ml, and 0.0158 ng/ml for GPC-1, leptin, OPN and VEGF, respectively. The serum circulating level of GPC-1, leptin, OPN, and VEGF in a mixture of 10 healthy normal human serum was 25.17 ng/ml, 18.04 ng/ml, 11.34 ng/ml, and 1.55 ng/ml, which was within the assay dynamic detection range for each analyte. Moreover, a 20% increase of GPC-1 and OPN was observed by spiking the normal human serum with recombinant antigens to confirm the accuracy of the assay. We observed no cross-reactivity among the four biomarker analytes, which eliminates the false positives and enhances the detection accuracy. The developed single upconversion nanoparticle-assisted single-molecule assay suggests its potential in clinical usage for prostate cancer detection by monitoring tiny concentration differences in a panel of serum biomarkers.

Original languageEnglish
Pages (from-to)400-410
Number of pages11
JournalCytometry Part A
Issue number5
Early online date29 Sep 2021
Publication statusPublished - May 2022
Externally publishedYes


  • prostate cancer
  • serum biomarkers
  • single-molecule immunoassay
  • upconversion nanoparticles


Dive into the research topics of 'Upconversion nanoparticle-assisted single-molecule assay for detecting circulating antigens of aggressive prostate cancer'. Together they form a unique fingerprint.

Cite this