Novel fluorescent C2-symmetric sequential on-off-on switch for Cu2+ and pyrophosphate and its application in monitoring of endogenous alkaline phosphatase activity

Anup Pandith, Kashi Raj Bhattarai, Ravi Kumara Guralamatta Siddappa, Han Jung Chae, Young Jun Seo

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)

Abstract

A doubly armed hydrazone-based FLRHYDDFP probe selectively detects Cu2+ and pyrophosphate (PPi) ions through an colorimetric response-“colorless → yellow → colorless”- as well as “on-off-on” photonic switching response under physiological conditions in a sequential manner. The binding stoichiometries of the analytes Cu2+ and PPi were 1:2 and 2:4 for FLRHYDDFP-Cu2+ and Cu2+/PPi, respectively. The sequential sensing ability of FLRHYDDFP toward Cu2+ and PPi, attributed to effective complexation-aided d→π* electron transfer (ET) from Cu2+ to FLRHYDDFP and intramolecular charge/electron transfer from FLRHYDDFP to FLRHYDDFP+, resulted in the formation of a non-symmetric Cu2+ chelate that provided a yellow-colored solution with a significant bathochromic shift from 376 to 446 nm in the UV–vis spectrum and quenching in the emission spectrum. Upon addition of PPi, Cu2+ was extruded from the complex, resulting in a revival of the fluorescence centered at 572 nm. Thus, sequential addition of Cu2+ and PPi yielded a colorless–yellow–colorless transition under visible light and on-off-on switching under 365-nm light (fluorescence). The lowest detection limits for Cu2+ and PPi, when using colorimetric and fluorimetric methods, were in the sub-micromolar and nanomolar levels, respectively. By exploiting this PPi sensing strategy, invitro as well as endogenous alkaline phosphatase activity could be monitored effectively, as demonstrated by exploiting the intracellular production or residual PPi in human salivary glands (normal) and cancer cell lines.

Original languageEnglish
Pages (from-to)730-742
Number of pages13
JournalSensors and Actuators, B: Chemical
Volume282
DOIs
Publication statusPublished - Mar 1 2019
Externally publishedYes

Keywords

  • C symmetry
  • d→π* Electron transfer
  • Endogenous alkaline phosphatase
  • Human salivary gland cells and cancer cells
  • Hydrazone
  • Intramolecular charge/electron transfer

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Novel fluorescent C2-symmetric sequential on-off-on switch for Cu2+ and pyrophosphate and its application in monitoring of endogenous alkaline phosphatase activity'. Together they form a unique fingerprint.

Cite this