Due to their slight structural differences, the rapid identification of benzimidazole fungicides is challenging. In this study, three benzimidazole fungicides (FBZ, CBZ and TBZ) with similar structures were added to the 2C30@3Q[8] host–guest complex. The solutions changed color, suggesting that a reaction occurred. Based on this host–guest interaction, a supramolecular colorimetric sensor array was constructed by extracting the red, green and blue (RGB) color change of the host–guest complex in response to fungicides. Linear discriminant analysis (LDA) identified and distinguished the benzimidazole fungicides with similar structures. The supramolecular colorimetric sensor array was in the 1–20 μM range. The Euclidean distance of the array showed excellent linear correlation with the fungicide concentration, with a 10−7 mol/L detection limit and a signal-to-noise ratio of 3. The colorimetric sensor array clearly distinguished between the binary and ternary fungicide mixes. The sensor array was integrated with machine learning to predict TBZ concentrations in river water. The applicability of the supramolecular colorimetry sensor array was verified by distinguishing and identifying three benzimidazole fungicides in river water and fruit skin.
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