Practical High-Performance Lateral Flow Assay Based on Autonomous Microfluidic Replacement on a Film

Abstract

Although paper-based microfluidic devices are an ideal platform for point-of-care (POC) diagnostics, it is difficult to achieve microfluidic control required for sensitive analyses such as ELISA on a paper substrate. Here, we present a novel lateral-flow test chip that can perform operations similar to a pump, such as flowing, stopping, and replacing a solution, just by adding the solution onto an inlet port. The chip was fabricated by laminating paper, film, and adhesive tape. For sensitive and accurate detection in an immunoassay, the transparency and flatness of the substrate is crucial for precise analysis of weak light generated by a specific antigen-antibody reaction; however, paper is not flat and is opaque. Therefore, transparent film was applied to the detection area of the chip in this study. The chip showed a good correlation at 0.1 -100 ng ml -1 concentrations of C-reactive protein, demonstrating high quantitative analysis of CRP in serum suitable for clinical trials. The signal intensity of the novel chip was higher than that of a chip made of nitrocellulose membrane, and the variation was smaller. The limit of detection of the chip was 0.1 ng ml -1 , whereas that of the nitrocellulose membrane was 100 ng ml -1 . This novel chip can be used for sensitive sandwich immunoassays just by adding solutions.

Sensitivity enhancement in lateral flow assays: a systems perspective

“…They tested the performance of their system against a conventional C-reactive protein LFA and reported 1000-fold sensitivity improvement in their system over the LFA. 81 Limitations. The transport/signal category contains complementary approaches to the reduction of optical noise in LFAs.…”

Weakly ionized gold nanoparticles amplify immunoassays for ultrasensitive point-of-care sensors

“…Comparing the LOD and detection range, the developed weakly ionized AA-AuNP LFIAs are superior to the reported fluorescent LFIAs and CL LFIAs (Fig. 4, G to I, and table S1) (9,22,25,(53)(54)(55)(56)(57). When taking the LOD value as an index, the straightforward colorimetric AA-AuNP LFIAs are comparable to the complicated SERS LFIAs and nanozyme LFIAs (table S1) (39,(58)(59)(60)(61).…”

Vibration Induced Flow Facilitating Affinity-Based Aggregation for Rapid Detection and Quantification of Nanoparticles

“…[8,9] Immunoaffinity chromatography, a typical simple diagnostic tool, can detect antigens in a short time (<10 min), but its sensitivity is low (approximately 10 × 10 11 /mL), and quantitative measurement is difficult. [10,11] When more sensitive and quantitative detection is required, enzyme-linked immunosorbent assay (ELISA) is often employed.…”