IMPACT OF AN N-HETEROCYCLIC ANALOGUE AS A COUPLING AGENT ON THE UV-VISIBLE SPECTROSCOPIC CHARACTERIZATION OF AMINO ACIDS

Abstract

This study explores the use of a multinuclear bisbenzimidazolium salts as coupling agents in UV-visible spectroscopic detection of amino acids. Significant improvements in absorption maxima are observed for the coupled amino acids, with as much as a +115 nm red shift of L-alanine absorption and greater than 50% increases in absorbance across all amino acids tested. Post coupling, L-alanine had a limit of detection of 3.1 µM and the limit of detection for amino acids was reduced by over 60%. Maximum sensitivity and chromogenic stability were obtained at pH 6.8 and a temperature of 50°C. The robustness of the methodology is confirmed by recovery data in excess of 97% in complex matrices, making the methodology suitable for clinical diagnostics and food safety applications. The obtained results demonstrate that heterocyclic compounds can be a revolutionizer in the field of analytical chemistry due to their potential to overcome limitations associated with conventional techniques of amino acids detection with their option of being as mild, green and efficient.