Benzimidazole based ratiometric and colourimetric chemosensor for Ni(II)

Area of Science:

• Analytical Chemistry
• Materials Science
• Computational Chemistry

Background:

• Nickel ions (Ni2+) are prevalent in physiological and environmental samples.
• Accurate detection of Ni2+ is crucial for environmental monitoring and biological studies.
• Existing detection methods may lack selectivity or sensitivity for Ni2+.

Purpose of the Study:

• To develop a highly sensitive and selective colorimetric chemosensor for Ni2+ detection.
• To investigate the sensing mechanism and electronic properties of the Ni2+-chemosensor complex.
• To demonstrate the practical applicability of the chemosensor in real-world samples.

Main Methods:

• Synthesis of a benzimidazole-based chemosensor (HL).
• Colorimetric and UV-Vis spectroscopic analysis for cation sensing.
• Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) calculations for electronic structure and mechanism elucidation.

Main Results:

• The synthesized chemosensor HL demonstrated high sensitivity and selectivity for Ni2+ detection over other common metal ions.
• A distinct visual color change from orange-yellow to blue was observed upon Ni2+ binding.
• UV-Vis spectroscopy showed a significant red shift from 403 nm to 600 nm with an isosbestic point at 500 nm.
• DFT and TD-DFT calculations provided insights into the electronic structure and sensing mechanism of the HL-Ni2+ complex.

Conclusions:

• The benzimidazole-based chemosensor HL is an efficient tool for the selective colorimetric detection of Ni2+.
• The sensor's visual color change and spectral response facilitate easy and accurate Ni2+ identification.
• Computational studies support the experimental findings and elucidate the sensing mechanism, paving the way for further sensor development.