A peptide-based fluorescent chemosensor for measuring cadmium ions in aqueous solutions and live cells

Abstract

A novel peptide fluorescent chemosensor (H2L) with a lysine backbone and both -NH2 sites conjugated with cysteine and dansyl groups has been designed and synthesized by solid phase peptide synthesis with Fmoc chemistry. This chemosensor is a promising analytical tool for detecting Cd(2+) based on the photo-induced electron transfer (PET) effect by turn-on response in 100% aqueous solutions. As designed, H2L exhibits excellent cell permeation and low biotoxicity as well as displaying relatively high selectivity and sensitivity. The chemosensor penetrated live HeLa cells and detected intracellular Cd(2+) by turn-on response. The binding stoichiometry and affinity, interference test, pH sensitivity, fluorescence quantum yield, quantum mechanical calculations, lifetimes, and cytotoxicity of the chemosensor H2L to Cd(2+) were also investigated. Moreover, H2L exhibits low biotoxicity with a limit of detection (LOD) for Cd(2+) of about 52 nM, implying that H2L can be used as a highly selective and sensitive peptide fluorescent chemosensor in biological systems.

Applications of Material-Binding Peptides: A Review

“…Since their inception, nanomaterials have remained a promising area of research, but their low solubility and poor biocompatibility hinder their in vivo applications . Moreover, traditional bioconjugation technology is inefficient and does not meet the requirements of clinical and technological applications. − Peptides are potential nanomaterial synthesis tools, which hold great promise for the development of nanotechnology. − MBPs are green and advanced targeted adhesives that can be used to functionalize the surface of various solid materials (Figure ). − Nanocomponents formed by the self-assembly of bound peptides have been widely used in various fields. ,, MBPs provide a simple and versatile approach to bioembedding for material functionalization that is simpler and more effective than existing bioconjugation techniques, such as the EDC (1-ethyl-3-[3-(dimethylamino)­propyl] carbodiimide hydrochloride) and NHS ( N -hydroxysuccinimide) .…”

A phenazine-imidazole based ratiometric fluorescent probe for Cd2+ ions and its application in in vivo imaging

“…may cause the increase of cadmium contamination in different spheres of the environment and living organisms. [7][8][9][10][11][12] As a result, rapid and sensitive detection and monitoring of cadmium levels in environmental and biological systems are very important.…”

Fluorescence “on–off–on” peptide-based chemosensor for the selective detection of Cu2+ and S2− and its application in living cell bioimaging

“…Based on these advantages, developing peptide-based fluorescence chemosensors, which can be used in in vivo and in vitro imaging has become a fashionable research topic in chemical biology. [31][32][33][34][35][36] On the basis of our group's work, [37][38][39][40] a novel selective fluorescence chemosensor L (Dansyl-Ser-Pro-Gly-His-NH 2 ) based on a tetra-peptide conjugated with dansyl groups has been designed and synthesized using solid phase peptide synthesis. As designed, the dansyl groups are the fluorophore, Pro-Gly is the spacer and Histidine (His) and Serine (Ser) are the ionophores, which offer binding sites to coordinate copper ions in an aqueous solution.…”