A nitrocellulose/cotton fiber hybrid composite membrane for paper-based biosensor

Nitrocellulose (NC) membrane was fabricated and tested for its potential use in various paper-based biosensors for use in point-of-care testing. However, contemporary technologies are complex, expensive, non-scalable, limited by conditions, and beset with potentially adverse effects on the environment. Herein, we proposed a simple, cost-effective, scalable technology to prepare nitrocellulose/cotton fiber (NC/CF) composite membranes. The NC/CF composite membranes with a diameter of 20 cm were fabricated in 15 min using papermaking technology, which contributes to scalability in the large-scale production of these composites. Compared with existing commercial NC membranes, the NC/CF composite membrane is characterized by small pore size (3.59 ± 0.19 μm), low flow rate (156 ± 55 s/40 mm), high dry strength (up to 4.04 MPa), and wet strength (up to 0.13 MPa), adjustable hydrophilic-hydrophobic (contact angles ranged from 29 ± 4.6 to 82.8 ± 2.4°), the good adsorption capacity of protein (up to 91.92 ± 0.07 μg). After lateral flow assays (LFAs) detection, the limit of detection is 1 nM, which is similar to commercial NC membrane (Sartorius CN 140). We envision the NC/CF composite membrane as a promising material for paper-based biosensors of point-of-care testing applications.