Multifunctional probe based on modified Ag&Mn:ZnInS QDs for dual-mode fluorescence and magnetic resonance imaging of intracellular glutathione

Glutathione (GSH) plays vital roles in a variety of biological processes, and the development of simple and effective GSH detection method is an important research topic. Herein, a multifunctional probe based on Ag&Mn:ZnInS quantum dots (QDs) was developed for bimodal imaging of GSH. MnO₂, as an efficient fluorescence quencher, was in-situ grown on the surface of QDs, and then modified with hyaluronic acid (HA) to improve the stability and targeted recognition capability of the probe due to the binding between HA and CD44 receptors. After MnO₂ was deconstructed by GSH, the fluorescence of the probe was recovered and the generated Mn²⁺ could serve as good magnetic resonance imaging (MRI) contrast agent. Moreover, the near-infrared emission probe was successfully employed in living cell and zebrafish imaging due to its low toxicity and high anti-biological interference performance. This strategy provides a simple dual-mode fluorescence/MRI imaging of GSH, which may have a broad application in biological detection.