Electrochemical behavior of nicotinamide using carbon paste electrode modified with macrocyclic compounds

Hydrogen bonding and π-π stacking in nicotinamide/H2O mixtures

The interactions between nicotinamide (NA) and H₂O were studied using UV-visible spectra (UV-Vis), cyclic voltammetry (CV), nuclear magnetic resonance (NMR), density functional theory (DFT) and atoms in molecules (AIM) analysis. According to the changes of the UV-Vis spectra and the oxidation and reduction potentials in cyclic voltammograms of NA in aqueous solution, it was found that hydrogen bonding occurred between NA and H₂O molecules. Quantum chemistry calculations and AIM analysis further confirmed the existence of hydrogen bonding between H₂O molecules and the amide group, the nitrogen atom, and hydrogen atoms on the pyridine ring of NA molecules. In addition, the NMR results demonstrated that the π-π stacking between NA pyridine rings could be formed at higher concentrations.

A potential-gated molecularly imprinted smart electrode for nicotinamide analysis

Triggered surface responsiveness paves the way for smart sensor technologies that not only have tunable retention, but also provide sensing through a ‘built-in’ programming of electrode material.