Degradable carboxymethyl cellulose/chitosan sponge swabs for sustainable diagnostics

Nucleic acid testing for viral detection typically relies on disposable swabs made from traditional polymers, such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). However, the non-degradable nature of these materials leads to the accumulation of solid medical waste, with disposal methods, such as incineration and landfilling, posing significant environmental and economic challenges. To address this issue, we present a sustainable alternative: a degradable sampling swab fabricated from degradable biopolymers, carboxymethyl cellulose (CMC) and chitosan (CS), to mitigate environmental impact. The integration of CS into the CMC matrix enhances the mechanical properties of the swab through the formation of the hierarchically structured coral fiber cluster (CFC). Compared to commercial flock swabs, the developed hierarchically porous sponge swabs demonstrate a 16 % higher viral protein release rate in quantitative detection and a 3 % improvement in sample collection performance. After use, the swab can be fully dissolved or degraded through acid/alkali treatments or natural degradation within a short period. This approach provides a high-performance tool for viral detection and offers a practical and effective solution to reducing medical waste, aligning with sustainable diagnostics.