Liquid-Phase Barrier Modified Nitrocellulose Membrane: A Strategy for Boosting Chemiluminescent Detection in Lateral Flow Assays

Lateral flow assay (LFA), as one of the most well-known methods in point-of-care testing platforms, has attracted great interest in disease detection due to its low cost, portability, ease of use, and short response time. However, the sensitivity of LFA and its widespread application in disease monitoring remain challenging problems. Herein, we report a liquid-phase barrier-modified nitrocellulose (NC) membrane in chemiluminescence LFA (CL-LFA) for the detection of cardiac troponin I (cTnI), which shows high sensitivity, specificity, and stability. The dissolvable paraffin liquid barrier increases the viscosity of the applied analyte solution and also the reaction time on the test and control lines during flow, significantly improving the performance of the device. The modified CL-LFA device achieved highly sensitive detection in the concentration range of about 0.1-20 ng·mL^-1. Clinical samples from acute myocardial infarction patients were also tested with the modified NC-based LFA, which showed good agreement with hospital results. Our method breaks new ground in improving the detection performance of LFA and thus has great potential for monitoring protein biomarker levels in various scenarios.