Natural Peptide Probe Screened for High-Performance Fluorescent Sensing of Copper Ion: Especially Sensitivity, Rapidity, and Environment-Friendliness

Abstract

Copper, one of the most important metal elements, has been a new favorite in research areas. However, the Cu2+ detection strategy with high-efficient and biocompatibility maintains importance. Here, we made effort to develop a new sensor with above advantages for Cu2+ detection. By virtue of rich coordination sites (amidogen and carboxyl) and fluorescence property of aromatic amino acids that which are also essential for living organism, monomers and combinations of them are designed to interact with Cu2+, attractively, the short peptide of tryptophane–phenylalanine (Trp–Phe) held stronger fluorescence emission and displayed much more significant response to Cu2+ than other molecules; thus, Trp–Phe was screened as a new fluorescent sensor for Cu2+ detection. It had a rapid response to the target ion via a coordination-mediated PET effect, the signal change reached the maximum within 10 s; cell proliferation experiments verified that the screened peptide had excellent biocompatibility, implying that it had great environment-friendliness and convenience for practical application in Cu2+ detection; high selectivity and a wide linear detection range from 10 to 1500 nM were achieved, with a lowest detectable concentration of 10 nM, which are superior to conventional optical strategies; through analysis of real water samples, good recoveries and consistencies with classical inductively coupled plasma mass spectrometry indicated that this strategy had promising potential for practical application, especially significant for Cu2+ detection in drinking water; and in addition, Cu2+ antidotes identification was successfully carried out, implying useful contribution to medical therapy and sewage treatment.

Graphene Oxide Nanosheets Tailored With Aromatic Dipeptide Nanoassemblies for a Tuneable Interaction With Cell Membranes

“…The addition of Cu 2+ quenches the fluorescence emission of both dipeptides due to the complex formation (Li et al, 2019). No significant changes are displayed in the maximum of absorption and emission bands for both dipeptides; only an increase of intensity indicative of larger aggregates formation.…”

A Review on Recent Advances in Peptide‐based Fluorescence Probes and their Potential Applications

“…designed several short peptides, including Trp−Phe, Tyr−Trp and Phe−Tyr dipeptide, and used them to interact with Cu 2+ . The results showed that the Trp‐Phe has strong fluorescence emission ability and obvious response to Cu 2+ , which can be used to detect Cu 2+ as a fluorescence probe [39] …”

“…A. Peptide basic fluorescence for sensing Cu 2+ . Reproduced with permission [61] . Copyright 2019, American Chemical Society.…”

“…The results showed that the Trp-Phe has strong fluorescence emission ability and obvious response to Cu 2 + , which can be used to detect Cu 2 + as a fluorescence probe. [39]…”

A Copper-Selective Sensor and Its Inhibition of Copper-Amyloid Beta Aggregation

“…Fluorescent sensors [10][11][12] have been widely used for detecting and monitoring Cu 2+ due to their high biocompatibility [13]. Copper has also been recently detected by peptide sensors such as the dipeptide Trp-Phe [14], the human Gly-His-Lys peptide [15], and peptide sensors discovered through peptide library screening such as Ser-Ala-Gln-Ile-Ala-Pro-His [16].…”