Investigating the Chemosensor Screening of Zn²⁺ and PPi Ions of Biological Importance

Abstract

This study investigates the development and evaluation of chemosensors for the selective detection of zinc ions (Zn²⁺) and pyrophosphate ions (PPi) of biological significance. Zinc is the second most abundant transition metal in humans after iron, playing crucial roles in enzymatic reactions, gene expression, and cellular processes. Pyrophosphate serves as a critical anion in ATP hydrolysis, DNA replication, and metabolic activities. The research objective was to synthesize and characterize novel fluorescent chemosensors based on benzothiazole, naphthalene carbohydrazone, and rhodamine derivatives for sequential detection of Zn²⁺ and PPi ions. The methodology employed spectroscopic techniques including UV-visible absorption, fluorescence emission, and NMR spectroscopy for sensor characterization and analyte binding studies. Synthesized chemosensors demonstrated remarkable selectivity with detection limits ranging from 2.36 × 10⁻⁸ M to 7.5 × 10⁻⁷ M for Zn²⁺ and 2.06 × 10⁻⁸ M to 4.73 × 10⁻⁶ M for PPi. Results indicated successful "turn-on" fluorescence enhancement for Zn²⁺ detection through chelation-enhanced fluorescence mechanisms and subsequent "turn-off" response for PPi through metal displacement. The developed sensors showed excellent performance in real sample analysis and biological imaging applications, providing valuable tools for environmental monitoring and biomedical diagnostics.