Immobilization Techniques and Integrated Signal Enhancement for POC Nanocolor Microfluidic Devices

Figure 3

Quantification of REA signal intensity. (a) Photos of REA chips after analyte detection are shown. For quantification the color profile of the images was converted to grayscale (8-bit) and the gray values at rim and center of the spotted area as well as the value of the background were determined (indicated by black circles; for more details, see Section 2). Quantification of the grayscale image was considered to correspond best with the actual REA color intensity and thus was preferred over measuring the contribution of one of the three channels: red (= R), green (= G), and blue (= B). (b) REA color intensities at the rim and center of the spots on the tested chips prepared by protocols 1–4 are shown in % black (black = 100%, white = 0%) (protocols 1 and 2: ; protocols 3 and 4: ). (c) The differences (delta) of average REA color intensities at rim and center [delta = intensity (rim) − intensity (center)] are shown in % black.

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