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

Chemistry. 2020 Jul 14;26(39):8511-8517. doi: 10.1002/chem.202001160. Epub 2020 Jun 17.

Abstract

A nanopore-based CuII -sensing system is reported that allows for an ultrasensitive and selective detection of CuII with the possibility for a broad range of applications, for example in medical diagnostics. A fluorescent ATCUN-like peptide 5/6-FAM-Dap-β-Ala-His is employed to selectively bind CuII ions in the presence of NiII and ZnII and was crafted into ion track-etched nanopores. Upon CuII binding the fluorescence of the peptide sensor is quenched, permitting the detection of CuII in solution. The ion transport characteristics of peptide-modified nanopore are shown to be extremely sensitive and selective towards CuII allowing to sense femtomolar CuII concentrations in human urine mimics. Washing with EDTA fully restores the CuII -binding properties of the sensor, enabling multiple repetitive measurements. The robustness of the system clearly has the potential to be further developed into an easy-to-use, lab-on-chip CuII -sensing device, which will be of great importance for bedside diagnosis and monitor of CuII levels in patients with copper-dysfunctional homeostasis.

Keywords: ATCUN; copper; fluorescence; nanopores; sensors.

MeSH terms

  • Copper / analysis*
  • Copper / chemistry
  • Copper / metabolism
  • Fluorescence
  • Humans
  • Ions / chemistry*
  • Peptides / chemistry*
  • Peptides / metabolism

Substances

  • Ions
  • Peptides
  • Copper