Colorimetric sensor array-based artificial olfactory system for sensing Chinese green tea’s quality: A method of fabrication

Figures & data

Figure 1. List of chemical dyes used to fabricate the sensor array.

Figure 2. Schematic of the colorimetric sensor array-based artificial olfactory system.

Figure 3. Difference images of sensors array for six grades of green tea (first three lines indicate prophyrins and metalloporphyrins dyes, and the last line indicates three pH indicators).

Figure 4. Cluster plot of PCA for different tea grades.

Table 1. Classification results of tea grades in calibration and prediction sets

		Discrimination results
Subsets	Sample grade	Grade 1	Grade 2	Grade 3	Grade 4	Grade 5	Grade 6	Discrimination rate
		15	1					85%
	Grade 2	5	11
	Grade 3		1	13	3
	Grade 4				17
	Grade 5					15	2
	Grade 6					3	14
Prediction set	Grade 1	8	1					86%
	Grade 2	4	5
	Grade 3			7	1
	Grade 4				8
	Grade 5					8
	Grade 6					1	7

Figure 5. Discrimination rates of BP-ANN model for different numbers of PCs.