Fig. 4.

Sensitivity enhancement based on flow block. A (a)SEM image for the transversal cut of wax pillars area on LFA. (b) Surface profile roughness of LFA modified with wax pillars. (c) Schematic of a transversal cut of pillars zone on nitrocellulose membrane [86]. B Sensitivity enhancement in LFA by creating a PDMS barrier. (a) Effects of PDMS droplets numbers on LOD. (b) Results of flow velocity simulation of LFA [87]. C Schematic diagram of fluidic control in a paper–agarose hybrid material–based LFA [88]