designed mould, so the exact size of the PAD can be predicted from
the initial mould used. The crucial parameters to determine the resolution
of the PAD were the melting temperature of the wax and
the dipping time. The smallest hydrophilic channel that can be fabricated
using this proposed method measures about 639
±
7 m in
width, which is sufficient for fabrication of the microfluidic paper
based assay. Multiple colorimetric assays can be simultaneously
performed on the PAD, and the results revealed the ability to analyse
glucose and protein in real samples. The wax dipping procedure
preserves the native paper surface, therefore this technique does
not face the problem of interference from residues remaining in the
hydrophilic channel.