| Autor: |
Zheng YJ; School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China., Luo JJ; School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China., Zou HL; School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China., Xing K; Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore., Luo HQ; School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China., Gao ZF; School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China., Li NB; School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China., Leong DT; Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore., Li BL; School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China. |
| Abstrakt: |
The coffee-ring effect is an eye-catching circle originating from a material-suspended liquid droplet at a solid substrate after liquid evaporation, but the low speediness has restricted practical applications. When nanomaterial aqueous solutions are dropped onto porous nitrocellulose (NC), the liquid is immediately absorbed through the porous tunnels of paper fibers, and nanomaterials are rapidly enriched on the contact lines between droplets and membranes. We called this ultrafast variant of the coffee ring effect the "tunneling coffee ring" (TCR). When nanomaterial sizes are smaller than that of pores, a larger-diameter ring of nanomaterials quickly materializes. The real-time particle size-dependent TCRs and liquid diffusion rings exhibit a dual-ring pattern on the NC membrane. The tunneling speed of the capillary effect is so fast that the pattern appears within seconds. We apply the TCR effect as a size-surface affinity-particle/fluid separation sensor for bacteria. Dextran-modified Au and MoS 2 nanostructures are proposed to be antibody-free microbe kits. Our TCR effect is used to distinguish between particles of different sizes and affinities, which are highly relevant in complicated systems without electricity and equipment in resource-poor settings. |
