Fabrication of an electrospun polycaprolactone substrate for colorimetric bioassays.

Colorimetric assays rely on detecting colour changes to measure the concentration of target molecules. Paper substrates are commonly used for the detection of biomarkers due to their availability, porous structure, and capillarity. However, the morphological and mechanical properties of paper, such as fibre diameter, pore size, and tensile strength, cannot be easily tuned to meet the specific requirements of colorimetric sensors, including liquid capacity and reagent immobilisation.