Highly sensitive pork meat detection using copper(ii) tetraaza complex by electrochemical biosensor

Area of Science:

• Coordination Chemistry
• Biophysical Chemistry
• Analytical Chemistry

Background:

• Copper(II) tetraaza complexes are of interest due to their diverse coordination environments and potential applications.
• Investigating the interaction of metal complexes with DNA is crucial for understanding their biological activity and developing novel therapeutic or sensing agents.
• Calf thymus DNA (CT-DNA) is a standard model for studying DNA-metal complex interactions.

Purpose of the Study:

• To synthesize and characterize novel copper(II) tetraaza complexes.
• To investigate the binding modes and strengths of these complexes with CT-DNA.
• To develop a selective and sensitive biosensor for pork detection using the most effective DNA-binding complex.

Main Methods:

• Complex synthesis and characterization using FTIR, 1HNMR, and 13CNMR spectroscopy.
• DNA binding studies employing UV-vis absorption, luminescence titrations, and viscosity measurements.
• Molecular docking simulations to elucidate binding interactions.
• Development and testing of a biosensor for real sample analysis.

Main Results:

• Three copper(II) tetraaza complexes (1a, 2a, 2b) were successfully synthesized and confirmed.
• All complexes exhibited electrostatic binding to CT-DNA, with binding strengths ordered as 2b > 1a > 2a.
• Complex 2b demonstrated the highest binding affinity and was utilized to create a pork biosensor.
• The developed biosensor showed a wide linear dynamic range, low detection limit, high selectivity, and reproducibility for pork detection over chicken and beef.

Conclusions:

• The charge and counter anions of copper(II) tetraaza complexes significantly influence their DNA binding strength.
• Complex 2b is a promising candidate for DNA interaction studies and biosensing applications.
• The developed biosensor offers a selective and sensitive method for authenticating pork meat in real samples.