Ultrasensitive and Selective Copper(II) Detection: Introducing a Bioinspired and Robust Sensor.

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomedical Engineering

Background:

• Copper (Cu^II) dysregulation is linked to various diseases.
• Accurate and sensitive detection of Cu^II is crucial for medical diagnostics.
• Existing methods for Cu^II detection can be limited in sensitivity or selectivity.

Purpose of the Study:

• To develop an ultrasensitive and selective nanopore-based sensing system for Cu^II detection.
• To explore the potential applications of this system in medical diagnostics.
• To create a reusable sensor for monitoring Cu^II levels.

Main Methods:

• Utilized a fluorescent peptide (5/6-FAM-Dap-β-Ala-His) engineered into ion track-etched nanopores.
• Exploited the fluorescence quenching of the peptide upon selective binding of Cu^II ions.
• Investigated ion transport characteristics of the peptide-modified nanopore for Cu^II sensing.

Main Results:

• Achieved ultrasensitive and selective detection of Cu^II, distinguishing it from Ni^II and Zn^II.
• Demonstrated femtomolar detection limits for Cu^II in human urine mimics.
• Showcased the sensor's reusability after washing with EDTA, restoring Cu^II-binding properties.

Conclusions:

• The developed nanopore-based Cu^II-sensing system offers high sensitivity and selectivity.
• The system has significant potential for developing easy-to-use, lab-on-chip diagnostic devices.
• This technology could be vital for bedside diagnosis and monitoring of copper-dysfunctional homeostasis.