A fluorescent switch for sequentially and selectively sensing copper(ii) andl-histidine in vitro and in living cells

Abstract

Herein, we report the development of a new fluorescent switch for sequential and selective sensing of Cu(2+) and L-histidine (L-His) in vitro and in living cells for the first time. In the absence of metal ions, Ac-SAACQ-Gly-Gly-Gly-Lys (FITC) (1) exhibits comparable fluorescence to that of free FITC. In the presence of metal ions, 1 selectively coordinates to Cu(2+) , causing its fluorescence emission to be quenched via photoinduced electron transfer. Interestingly, the as-formed 1–Cu(2+) complex selectively responds to L-His among the 20 natural amino acids by turning its fluorescence on. This property of fluorescence switch of 1 was successfully applied for qualitatively and quantitatively sensing Cu(2+) and L-His in vitro. Using this dual functional probe, we also sequentially imaged Cu(2+) and L-His in living HepG2 cells. Our new probe 1 could be applied for not only environmental monitoring but also biomolecule detection in the near future.

Green and Red Fluorescent Dyes for Translational Applications in Imaging and Sensing Analytes: A Dual‐Color Flag

“…The amino acid l ‐histidine in its free form acts as a tridentate ligand towards transition‐metal ions such as Cu II . Wang and co‐workers report on water‐soluble fluorescent probe 33 , which selectively binds to Cu II ions; this binding causes quenching of the emission intensity through photoinduced electron transfer (limit of detection, LOD=1.6 μ m ). The 33 –Cu II complex can selectively detect histidine (LOD=1.6 μ m ) in the presence of the other naturally occurring amino acids and shows a “turn on” of the fluorescence signal.…”

A selective and sensitive near-infrared fluorescent probe for real-time detection of Cu(i)

“…[5][6][7] There is a growing body of evidence to suggest that the imbalance of Cu + may cause neurodegenerative disorders, such as prion, Parkinson's, Alzheimer's, Menkes, and Wilson's diseases and amyotrophic lateral sclerosis. [8][9][10][11] In addition, copper was also demonstrated to play a critical role in other diseases including urinary tract infection 12 and infertility. 13 It is of signicance, therefore, to establish an effective and reliable strategy to monitor Cu + in complex environmental settings and biological systems.…”

A colorimetric chemosensor for the sequential detection of copper ion and amino acids (cysteine and histidine) in aqueous solution

“…27,[40][41][42][43][55][56][57][58][59] The binding properties of 1-Cu 2+ complex with both Cys and His were further studied by UV-vis titration experiments. On the treatment with Cys to the solution of 1-Cu 2+ , the absorption band at 525 nm signicantly decreased, and the band gradually reached minimum at 6 equiv.…”