| Molecular recognition of organic compounds in aqueous solutions is inherently challenging, due to the potential interference from the very high concentration of water. This thesis describes a simple colorimetric sensor array that probes a wide range of chemical properties. By printing hydrophobic dyes on a hydrophobic membrane, sensor arrays are easily prepared with substantial chemical selectivity for the identification and quantification of various chemicals dissolved in water with a concentration range of 0.1 M to 1 μM. Upon immersion in aqueous solutions, digital imaging of the dye array before and after exposure to an analyte provides a color change profile that is a fingerprint for the chemical components of the solution. Chemometric and statistical analyses, including principal component analysis (PCA) and hierarchical clustering analysis (HCA) were used to analyze the digital databases. This technique has also been successfully applied to the analyses of complex mixtures; various commercial beverages, including sodas, beers and teas, were easily distinguished from one another. The potential applications of this sensor array technique to quality control/quality assurance purposes in the food and beverage industry has also been demonstrated. |
