Efficient Ensemble System Based on the Copper Binding Motif for Highly Sensitive and Selective Detection of Cyanide Ions in 100% Aqueous Solutions by Fluorescent and Colorimetric Changes

Abstract

A peptide-based ensemble for the detection of cyanide ions in 100% aqueous solutions was designed on the basis of the copper binding motif. 7-Nitro-2,1,3-benzoxadiazole-labeled tripeptide (NBD-SSH, NBD-SerSerHis) formed the ensemble with Cu(2+), leading to a change in the color of the solution from yellow to orange and a complete decrease of fluorescence emission. The ensemble (NBD-SSH-Cu(2+)) sensitively and selectively detected a low concentration of cyanide ions in 100% aqueous solutions by a colorimetric change as well as a fluorescent change. The addition of cyanide ions instantly removed Cu(2+) from the ensemble (NBD-SSH-Cu(2+)) in 100% aqueous solutions, resulting in a color change of the solution from orange to yellow and a "turn-on" fluorescent response. The detection limits for cyanide ions were lower than the maximum allowable level of cyanide ions in drinking water set by the World Health Organization. The peptide-based ensemble system is expected to be a potential and practical way for the detection of submicromolar concentrations of cyanide ions in 100% aqueous solutions.

Extracellular Cu2+ pools and their detection: From current knowledge to next-generation probes

“…[233][234][235] In this regard, care should be taken in using ATCUN-like motifs or in conjugating fluorophores to an ATCUN peptide amino-terminus, as the latter can be converted into an amide or an aromatic amine, drastically reducing the affinity for Cu 2+ . [236][237][238][239] More recently, we reported an ATCUN sensor conjugated to a luminescent Tb 3+ complex, in order to get rid of the autofluorescence background of biological media. [240] Effectively, this ATCUN-Tb 3+ sensor proved to be suitable to detect labile Cu 2+ fluctuations in the presence of competitors in a highly fluorescent background.…”

A new highly selective fluorescent sensor based on a novel fluorophore for cyanide and its applications in bioimaging

“…[ 6–9 ] Even low concentrations of CN − can cause poisoning, leading to vomiting, convulsions, unconsciousness, and even death. [ 10 ] Based on the relevant WHO regulations, the permitted maximum concentration of CN − in drinking water is about 1.9 μM. [ 11 ] Nevertheless, cyanide is widely used in many industrial processes and plays an irreplaceable role in processes such as the synthesis of fibres and adhesives, gold mining, and electroplating.…”

An Efficient Molecular Scaffold Exhibiting Fluorescence “Turn–On” Response for Cyanide and HCN

“…However, number of chemosensors for cyanide exhibiting enhanced, “ turn‐on ” emission are limited in number ,,. The detection of cyanide can be achieved by hydrogen bonding interaction, coordination or covalent bonding interactions,, displacement method (due to high affinity between metal‐ensemble and cyanide),‐ boron derivatives, quantum dots, and mesoporous silica material . Among these, colorimetric and fluorogenic chemosensors are of special interest because of their selectivity and the possibility of ‘‘naked‐eye’’ detection, without the use of expensive sophisticated instruments.…”