Design of Molecular Logic Gates Via pH-dependent Absorption and Fluorescence Transitions in Drug Molecules.

In this manuscript, we have explored the absorption and fluorescence properties of Sulfamethoxazole (SMX) and Trimethoprim (TMP) in the pH range 1-14. The absorption and fluorescence properties of SMX and TMP exhibit significant variations with changes in pH. These variations in absorption and fluorescence characteristics have been analyzed based on the existence of different species of these molecules in different pH ranges. The variations in absorption and fluorescence intensity of SMX and TMP molecules as a function of pH have been utilized to design two-input molecular logic gates, namely Improved-INHIBIT (I-INHIBIT) and IMPLICATION. Also, the absorption and fluorescence properties at different wavelength maxima have been utilized to design the same molecular logic gates.