Detection of basic amino acids under highly alkaline conditions using a perylene amine-derived probe

Spectrochim Acta A Mol Biomol Spectrosc. 2024 Mar 15:309:123835. doi: 10.1016/j.saa.2024.123835. Epub 2024 Jan 2.

Abstract

pH plays a crucial part in numerous chemical and physiological processes. In this work, a new perylene diimide derivative that acts as a pH-sensitive dye with Bay Area Carboxylic Acid functionality. The derivative utilizes the outstanding thermal, chemical and photochemical stability found in PDI materials and has remarkable UV-visible absorption and fluorescence emission qualities. Based on these properties, a fluorescent probe (PCA) was synthesised using a perylene tetracarbodiimide (PDI) backbone for the recognition of alkaline pH. In alkaline environments where the pH values are between 10 and 14, the fluorescence intensity significantly decreases, and a blue shift occurs, which is a standard feature of alkaline pH probes. The probe demonstrates exceptional sensing ability within the pH range of 10.00-14.00, with notable stability and reversibility. Encapsulation of the probe in a thin polymer film material enhances the pH sensing capability of the system. New sensor has been developed to detect basic amino acids by utilizing the probes' pH response characteristics. this sensor has also been applied to detect the concentration of arginine.

Keywords: Basic amino acids; Dual-responsive sensing paper; PDIs; Probe; pH-sensitive luminescence.