Superhydrophilic cotton thread with temperature-dependent pattern for sensitive nucleic acid detection

Cotton thread is promising in fabricating biosensors for diagnostic application due to its excellent characteristics. However, the enrichment of the capture molecules on a narrow zone of the cotton thread based biosensor is a big challenge because of its superhydrophilicity. Here, we report a simple, low-cost and accurate cotton thread based nucleic acid biosensor with temperature-dependent pattern. Liquid wax is used to fabricate temperature-dependent pattern to restrict the test zone in a narrow area. This biosensor enables visual and quantitative detection of target DNA by accumulation of gold nanoparticles (GNPs) on the test zone with a detection limits of 0.75nM. In addition, the cotton thread based biosensor needs less sample than previous reported lateral flow strip and the sample solution wicks faster at the cotton thread which can lead to a shorter detection time. This simple, low-cost and fast detection method holds great potential to improve healthcare services in the developing regions. •A simple and low-cost cotton thread based nucleic acid biosensor with temperature-dependent pattern (pCTNAB) was developed.•Liquid wax with tunable state was used to fabricate the pattern to enrich the capture molecular on a narrow test zone.•The sample wicked faster at the CTNAB and less sample was needed compared to the previous reported lateral flow strip.•The proposed sensor showed fine sensitivity, reproducibility and excellent anti-interference ability.