Multiple optical trapping assisted bead-array based fluorescence assay of free and total prostate-specific antigen in serum

• Published in: Sensors and actuators. B, Chemical Vol. 269; pp. 143 - 150
• Main Authors: Cao, Di, Li, Cheng-Yu, Qi, Chu-Bo, Chen, Hong-Lei, Pang, Dai-Wen, Tang, Hong-Wu
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.09.2018; Elsevier Science Ltd
• Subjects: Antigens; Arrays; Bead-array based assay; Beads; Biosensors; Fiber lasers; Fluorescence; Fluorescence imaging; Multiple optical tweezers; Nanoparticles; Optical trapping; Polystyrene resins; Prostate cancer; Prostate-specific antigen; Quantum dots; Sensitivity; Multiple optical tweezers; Bead-array based assay; Fluorescence imaging; Prostate-specific antigen; Prostate cancer
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2018.04.169

Simultaneous detection of free and total prostate-specific antigen (PSA) in serum is realized by combining multiple optical trapping and bead-based fluorescence bioassay with fluorescent quantum dots being used as the nanotags. [Display omitted] •Construction of multiple optical trapping assisted bead-array based assay.•Design of multiple optical trapping by splitting a single NIR laser beam with a diffraction optical element.•Simultaneous detection of fPSA and tPSA in serum.•High sensitivity is realized by the use of quantum dots as the nanotags. Although suspension bead-based assay technology has been widely used owing to its advantages of high-throughput and microvolume detection, its sensitivity is greatly limited because it detects the fluorescence signal emitted by microbeads for a short time in the flowing fluid. In this work, we present the approach for prostate-specific antigen (PSA) detection of both free PSA (fPSA) and total PSA (tPSA) based on bead-array based fluorescence imaging by combining multiple optical trapping and bead-based bioassays. The polystyrene beads were employed to enrich the targets using the classic sandwich immuno-binding and tagged with fluorescent quantum dots (QDs), and the QDs-tagged beads in suspension were trapped array-by-array using multiple optical tweezers constructed with a diffraction optical element and excited with a 405 nm fiber laser for wide-field fluorescence imaging. The distinctive size information from the image of the trapped beads enabled the sorting of different targets. Moreover, the limits of detection for fPSA and tPSA are 3.8 pg/mL and 2.5 pg/mL respectively with good specificity. More importantly, this strategy was successfully used to detect fPSA and tPSA simultaneously in real serum samples. The high sensitivity, good selectivity, and tiny sample volume make this strategy a promising method for life sciences and clinical applications.