Visual and fast detection of trace copper ions using biosensor based on FRET

Area of Science:

• Environmental Science
• Analytical Chemistry
• Biochemistry

Background:

• Copper ion detection is crucial for environmental monitoring.
• Existing methods may lack simplicity, speed, or sensitivity.
• Development of novel biosensors is needed for efficient copper analysis.

Purpose of the Study:

• To construct a simple, rapid, and sensitive fluorescence biosensor for copper ion detection.
• To utilize fluorescence resonance energy transfer (FRET) for selective copper ion sensing.
• To validate the biosensor's performance in real-world environmental samples.

Main Methods:

• A FRET-based biosensor was developed using copper binding protein CopC and dansyl chloride (DNS-Cl).
• DNS-Cl was attached to CopC under alkaline conditions, forming the DNS-Cl/CopC complex.
• Copper ion binding induced a significant decrease in DNS-Cl fluorescence, enabling detection.

Main Results:

• The DNS-Cl/CopC biosensor exhibited good linearity for copper ion detection in the range of 0.04-11μM (R=0.989).
• A low detection limit of 7nM for copper ions was achieved.
• The biosensor successfully detected copper ion levels in purified water, tap water, and industrial wastewater, with results consistent with ICP-MS.

Conclusions:

• The established DNS-Cl/CopC biosensor offers a credible method for sensitive and selective copper ion detection.
• This FRET-based biosensor is a powerful tool for monitoring environmental copper pollution.
• The method demonstrates potential for widespread application in environmental analysis.