Portable, facile microfluidic platform using a low-cost vacuum pump for multiplex biomarker detection in human samples

Portable multiplex microfluidic platforms are critically needed for point-of-care testing (POCT) of health-related biomarkers. The complex preparation processes and the use of expensive and bulky devices lead to increased detection costs, hindering the application of emerging POCT technologies. Here, we introduce a portable and versatile microfluidic platform for low-cost multiplex biomarker detection, integrated with a facile and easy-tooperated vacuum pump and mass-produced screen-printed carbon electrodes (SPCEs). The innovative pump, comprising only a syringe, a valve, and a spring, costs approximately $0.50. It operates by using the compressed spring to self-sufficiently drive reagents, which are actuated via a valve switch. The pump's performance was assessed under various conditions, demonstrating consistent operation and a broad pressure range. Additionally, electrocatalytic nanocomposites (Ti3C2Tx/Pt-Pd) were adopted to modify the SPCEs, resulting in high-efficiency performance (<15 min), cost-effectiveness (<$4 per test) and excellent reliability across a broad detection scope. Finally, the platform successfully achieved multiplex detection of biomarkers (glucose, uric acid and lactic acid) in serum, sweat and saliva. This simple and adaptable platform promises to facilitate cost-effective, multiplex biomarker detection, paving the way for large-scale POCT applications, particularly in resource-limited settings.