Discrimination of nucleotides by single fluorescence sensor under solvent-dependent recognition patterns

The chemosensor based on Zn complex of 1-[bis(pyridine-2-ylmethyl)amino]methylpyrene (1·Zn) was synthesized for detection of nucleotides in aqueous solution. This sensor has a high selectivity for PPi in aqueous solution. However, in the solution of DMSO:HEPES (0.01 M, pH 7.4, 90:10, v/v), 1·Zn selectively bound nucleoside polyphosphates such as ATP and UTP with a large fluorescence enhancement. Tremendously different recognition patterns of 1·Zn toward various phosphate anion based nucleotides in the two solvent systems encouraged us to discriminate the structurally similar nucleotide anions. The principal component analysis (PCA) was applied to discriminate 10 nucleotides in two solvent systems. This approach permits the identification of 10 phosphate analytes with nearly 100% accuracy from a single sensor in two solvent systems. To illustrate the utility of this approach for ATP hydrolysis application, the ratios between the product of reaction (PPi) and the reactant (ATP) were plotted versus the ratios of fluorescence intensity. The graph can be used for quantitative prediction of the PPi and ATP ratios with the detection limit of 2:8.