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Dual-color magnetic-quantum dot nanobeads as versatile fluorescent probes in test strip for simultaneous point-of-care detection of free and complexed prostate-specific antigen
- Rong, Zhen, Bai, Zikun, Li, Jianing, Tang, Hao, Shen, Tianyi, Wang, Qiong, Wang, Chongwen, Xiao, Rui, Wang, Shengqi
- Biosensors & bioelectronics 2019 v.145 pp. 111719
- adsorption, antibodies, biosensors, blood serum, chemical species, detection limit, diagnostic techniques, fluorescence, fluorescent dyes, hyperplasia, image analysis, immunoassays, information processing, iron oxides, magnetic properties, magnetism, mobile telephones, nanoparticles, patients, point-of-care systems, prostate-specific antigen, prostatic neoplasms, quantum dots
- Simultaneous detection of free and complexed prostate-specific antigen (f-PSA and c-PSA) is critical to the prostate cancer (PCa) diagnostic accuracy for clinical samples with PSA values in the diagnostic gray zone between 4 and 10 ng mL⁻¹. Herein, red and green magnetic-quantum dot nanobeads (MQBs) with superior magnetic property and high luminescence were fabricated via polyethyleneimine-mediated electrostatic adsorption of numerous quantum dots onto superparamagnetic Fe₃O₄ magnetic cores, and were conjugated with f-PSA antibody and c-PSA antibody, respectively, as versatile fluorescent probes in test strip for immune recognition, magnetic enrichment, and simultaneous detection of f-PSA and c-PSA analytes in complex biological matrix with t-PSA antibody on the test line. A low-cost and portable smartphone readout device with an application was also developed for the imaging of dual-color test strips and data processing. This assay can simultaneously detect f-PSA and c-PSA with the limits of detection of 0.009 ng mL⁻¹ and 0.087 ng mL⁻¹, respectively. Clinical serum samples of PCa and benign prostatic hyperplasia patients were evaluated to confirm the clinical feasibility. The results suggest that the proposed dual-color MQBs-based fluorescent lateral flow immunoassay is a promising point-of-care diagnostics technique for the accurate diagnosis of PCa even in resource-limited settings.