A novel colorimetric HSO4(-) sensor in aqueous media

Area of Science:

• Supramolecular Chemistry
• Analytical Chemistry
• Sensing Technology

Background:

• Development of selective anion receptors is crucial for chemical sensing.
• Schiff base derivatives offer versatile platforms for molecular recognition.
• Hydrogen sulfate (HSO4-) detection is important in various environmental and biological applications.

Purpose of the Study:

• To synthesize and characterize a novel Schiff base derivative as a chemosensor.
• To investigate the selective recognition of hydrogen sulfate (HSO4-) anions.
• To evaluate the sensing performance, including sensitivity and detection limits.

Main Methods:

• Synthesis and characterization of anion receptor 3.
• UV-vis spectroscopy and colorimetric analysis for anion detection.
• (1)H NMR titration to study binding interactions.
• Evaluation of selectivity against various competing anions.

Main Results:

• Receptor 3 exhibits distinct UV-vis spectral changes and visible color changes upon binding with HSO4-.
• The receptor demonstrates high selectivity for HSO4- over F-, Cl-, Br-, I-, AcO-, H2PO4-, and ClO4-.
• UV-vis and 1H NMR titrations confirm strong binding with an association constant (Ka) of 6.59×10^4 M⁻¹.
• A low detection limit of 2.0×10⁻⁶ mol L⁻¹ for HSO4- in aqueous solution was achieved.

Conclusions:

• A novel Schiff base chemosensor (3) has been successfully developed for selective HSO4- detection.
• The chemosensor allows for both visual and instrumental detection of HSO4-.
• The developed receptor shows potential for practical applications, including qualitative detection via test kits.