Regulation of probe density on upconversion nanoparticles enabling high-performance lateral flow assays

• Published in: Talanta (Oxford) Vol. 256; p. 124327
• Main Authors: Jin, Birui, Du, Zhiguo, Ji, Jingcheng, Bai, Yuemeng, Tang, Deding, Qiao, Lihua, Lou, Jiatao, Hu, Jie, Li, Zedong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2023
• Subjects: Bio-probe optimization; C-Reactive Protein; CRP detection; Fluorescent Dyes; Lateral flow assay; Limit of Detection; Nanoparticles; Paper microfluidics; Sensitivity enhancement; Lateral flow assay; CRP detection; Sensitivity enhancement; Bio-probe optimization; Paper microfluidics
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2023.124327

Upconversion nanoparticles (UCNPs)-based fluorescence probes have shown great potential in point-of-care testing (POCT) applications, due to UCNPs’ features of high photostability and background-free fluorescence. Ceaseless improvements of UCNPs-probes have been carried out to increase detection sensitivity and to broaden detection range of UCNPs-based POCT. In this paper, we optimized UCNPs-probes by regulating probe density. The optimization was verified by a traditional lateral flow assay (LFA) platform for C-reactive protein (CRP) detection. Further, the optimized UCNPs-LFA integrating with a home-made benchtop fluorescence analyzer holds the capability to achieve high-performance POCT. Finally, nearly a 20 times sensitivity enhancement with a limit of detection of 0.046 ng/mL and a broad detection range of 0.2–300 ng/mL for CRP detection was obtained. Moreover, the optimized UCNPs-LFA was applied to detecting CRP in clinical serum samples and the detection results were consistent with the clinical test, validating its clinical practicability. The proposed optimization method is also expected to optimize other nanoparticles-based bio-probes for wider POCT application. [Display omitted] •A simple and versatile method for optimization of UCNPs-probes by regulating probe density was developed.•Through introduction of blank probe, the probe density on UCNPs was controllably regulated, eliminating the nonspecific binding.•Nearly a 20 times sensitivity enhancement with a limit of detection of 0.046 ng/mL and a detection range of 0.2–300 ng/mL for CRP detection was obtained.•The optimized UCNPs-LFA integrating with a home-made benchtop fluorescence analyzer was developed for high-performance POCT.