A Colorimetric Sensor Array for Identification of Natural Amino Acids
Abstract The development of colorimetric sensor array for the detection of natural amino acids is reported. Using a cross-responsive array containing a diverse family of chemically responsive dyes, the colorimetric sensor array provides enormous discriminatory power among different analytes. Digital imaging of the dye array before and after immersion provides a color change profile as a unique fingerprint for each specific analyte. The 6×6 array used in this research has 36 dyes that were sensitive to amino acids. A functional portable type apparatus was developed for data acquisition and data processing. Using colorimetric sensor arrays, 10 natural amino acids have been analyzed within 5 min of exposure at concentrations of 375 μM. The digital data library generated was analyzed with statistical and chemometric methods, including principal component analysis (PCA) and linear discriminant analysis (LDA). Facile identification of all the amino acids was readily achieved using comparison of the color change profiles or a PCA score plot. Using LDA analysis, the classification accuracy of identification was 97%. These results suggest that colorimetric sensor arrays may prove to be useful for the identification of natural amino acids, and they also represent a potential application in the field of cell recognition, food quality assurance, and microbial identification.