Synthesis and chemosensor properties of Aza-BODIPY derivatives

Abstract

Three aza-BODIPYs DA, DM, and DP were synthesized and their application as chemosensors was investigated. The compounds were designed with dimethylaniline and alkyl group substituents. The DA, DM, and DP are capable of binding to Zn2+ ions through a mechanism which involved the binding at dimethylaniline group linked to the aza-BODIPY core. Upon the addition of Zn2+, a new absorption band appears at 650-680 nm, which correlates with a color change from blue to emerald and causes the changed charge transfer transition. All three compounds exhibit a slight bathochromic shift in their absorption spectra. The color change of the solution from blue to emerald green is visible to the naked eye. The custom-made colorimeter demonstrated a good linear relationship between electrical resistance and the concentration of Zn2+. The aza-BODIPY-embedded exhibited distinct color changes upon the exposure of Zn2+ in aqueous media. Additionally, DA-Zn2+ adduct exhibited a logic gate behavior as chemosensor for Cu2+. The environmental toxicity of these compounds was determined using the bacterium Pseudomonas putida, finding that at a concentration of 0.2 mg/mL, there were no harmful effects on the bacteria. Therefore, the synthesized aza-BODIPYs may be suitable as chemosensor probes for Zn2+ detection with low environmental effect.