Thioether-bridged carbon dots-dopamine quinone conjugate probe for glutathione sensing and discrimination between glioblastoma and normal cells.

in Talanta by Ningcheng Wei, Yi Xiao, Yang Jin, Liying Zhang, Panpan Chen, Shuhu Du

TLDR

  • Researchers have developed a novel, sensitive, and selective probe for detecting glutathione (GSH) in glioblastoma (GBM) cells, paving the way for early diagnosis and treatment of the disease.
  • The probe, CDs@S-DAQ, is a thioether-bridged fluorescence carbon dots conjugate that exhibits red emission and has the potential to discriminate between GBM cells and normal tissue cells based on GSH expression levels.

Abstract

Sensitive and specific recognition and imaging of glioblastoma (GBM) cells are crucial for early diagnosis in GBM. Herein, a novel thioether-bridged fluorescence carbon dots (CDs@S for short)-dopamine quinone (DAQ) conjugate (termed as CDs@S-DAQ) probe with red emission was fabricated for sensitive sensing of glutathione (GSH) and selective fluorescence imaging of GBM cells. Due to the strong photo-induced electron transfer (PET) effect between DAQ (the acceptor) and CDs@S (the donor), the red fluorescence of CDs@S is significantly quenched. In the presence of GSH, on the one hand, GSH reduces the quinone structure to a hydroquinone structure via Michael addition reaction, which eliminates the PET effect between DAQ and CDs@S, resulting in the fluorescence restoring of CDs@S; on the other hand, it simultaneously induces the cleavage of the thioether bond linking DAQ and CDs, causing DAQ to detach from the CDs surface and reducing the PET effect, which leads to the fluorescence recovery of CDs. It has been demonstrated that the response of CDs@S-DAQ probe to GSH has a good linear relationship in the range from 0.5 to 10 mM, with an Rvalue of 0.9978. Meanwhile, the as-fabricated CDs@S-DAQ probe has excellent stability, superior optical properties and low cytotoxicity. Based on these findings, the probe can be applied in live-cell fluorescence imaging, enabling discrimination between GBM cells and normal tissue cells according to their distinct GSH expression levels.

Overview

  • The study presents a novel probe for sensitive sensing of glutathione (GSH) and selective fluorescence imaging of glioblastoma (GBM) cells.
  • The probe, termed CDs@S-DAQ, is a thioether-bridged fluorescence carbon dots (CDs) conjugate with dopamine quinone (DAQ), exhibiting red emission.
  • The probe is designed to detect GSH and differentiate GBM cells from normal cells based on their GSH expression levels.

Comparative Analysis & Findings

  • The probe exhibits a good linear relationship in responding to GSH concentrations from 0.5 to 10 mM, with an R-value of 0.9978.
  • The CDs@S-DAQ probe demonstrates excellent stability, superior optical properties, and low cytotoxicity.
  • The probe enables live-cell fluorescence imaging, allowing for the discrimination of GBM cells and normal tissue cells based on their distinct GSH expression levels.

Implications and Future Directions

  • The probe has the potential to contribute to early diagnosis and treatment of GBM by detecting GSH expression levels in biopsies or biological fluids.
  • Future studies can explore the optimization of the probe's detection range, sensitivity, and specificity, as well as its potential applications in other diseases.
  • The development of more advanced probes with increased molecular targeting and improved imaging capabilities is crucial for further advancements in cancer diagnosis and treatment.
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