A series of concentrations of methyl parathion solutions
was tested in this manner and the results are presented.
As shown in Fig. 5b, in scanning the barcodes, at low concentrations
of methyl parathion (>0.1 μg mL−1) that have high
Y values (≥60%), the detection region of the barcode appears as
a wide bar, resulting in the app reading the assay as the negative
result “−”. At higher concentrations of methyl parathion
(≥0.5 μg mL−1), the Y value became low (