COMPUTATIONAL INVESTIGATION OF IMIDAZOLIUM IONIC LIQUIDS AND THEIR INTERACTIONS WITH CERTAIN BIO-SPECIES USING DENSITY FUNCTIONAL THEORY

Ionic liquids, particularly imidazolium-based variants, have gained significant attention due to their unique properties, such as tunable polarity, high thermal stability, and potential applications in electrochemical devices and biosensing. A detailed computational analysis of imidazolium-based ionic liquids (ILs) and their interactions with biologically significant molecules—dopamine, ascorbic acid, and uric acid—was conducted. Using Density Functional Theory (DFT) with the 6-311++G(d,p) basis set, the electronic properties, molecular structures, and interaction energies of three ILs—EMI-SCN, EMI-DCA, and BMI-PF6—were explored. Structural optimization, HOMO-LUMO gap analysis, and molecular electrostatic potential mapping were employed to uncover binding characteristics and reactivity of the ILs toward the biomolecules. Among the tested ILs, EMI-SCN exhibited the highest interaction energies with all analytes, particularly showing strong affinity for ascorbic acid, indicating its potential in electrochemical sensors. The calculated global reactivity descriptors support the stability and reactivity trends, with EMI-SCN demonstrating superior electronic and electrostatic interactions compared to EMI-DCA and BMI-PF6. EMI-SCN’s unique interaction profiles suggest its suitability for selective detection of dopamine, ascorbic acid, and uric acid in biological environments. These findings pave the way for the rational design of ionic liquids aimed at enhancing the performance of biosensors and electrochemical devices, offering improved sensitivity and selectivity for biological molecule detection.