Digital droplet immunoassay based on a microfluidic chip with magnetic beads for the detection of prostate‐specific antigen

Abstract

Sensitive biomarker detection techniques are beneficial for both disease diagnosis and postoperative examinations. In this study, we report an integrated microfluidic chip designed for the immunodetection of prostate‐specific antigens (PSAs). The microfluidic chip is based on the three‐dimensional structure of quartz capillaries. The outlet channel extends to 1.8 cm, effectively facilitating the generation of uniform droplets ranging in size from 3 to 50 μm. Furthermore, we successfully immobilized the captured antibodies onto the surface of magnetic beads using an activator, and we constructed an immunosandwich complex by employing biotinylated antibodies. A key feature of this microfluidic chip is its integration of microfluidic droplet technology advantages, such as high‐throughput parallelism, enzymatic signal amplification, and small droplet size. This integration results in an exceptionally sensitive PSA detection capability, with the detection limit reduced to 7.00 ± 0.62 pg/mL.

Single-molecule microfluidic assay for prostate-specific antigen based on magnetic beads and upconversion nanoparticles

“…Others used of carboxylated MBs in a quartz capillary-based droplet microfluidic chip. 38 The MB-bound sandwich immunocomplexes were introduced to a droplet-generating microfluidic chip, where the enzyme label reacted with a fluorescent substrate, achieving an LOD of 7 pg mL −1 . In a study utilizing an integrated magnetic microfluidic chip with a magnetoimpedance sensor, 48 the authors described a chip containing a reaction platform for immunocomplex formation.…”

“…, high throughput, effective manipulation, low sample consumption), it is necessary to develop simple yet effective techniques such as droplet microfluidics for digital detection. 37,38…”