CuS@CDs nanozymes with photothermal-enhanced peroxidase-like activities for colorimetric/fluorescent detection of glutathione and ferric ions in the coexisting system

Abnormal levels of glutathione (GSH) and ferric ions (Fe3+) can break the redox balance in the human body and lead to neurodegenerative diseases. However, it is still challenging to detect Fe3+ and GSH simultaneously in the coexisting system. Herein, a colorimetric/fluorescent sensing platform based on copper sulfide @ carbon dots nanocomposites (CuS@CDs NCs) is constructed for simultaneously detecting GSH and Fe3+ in the coexisting system. CuS@CDs NCs show photothermal effect, leading to the improvement of peroxidase-like activity of CuS@CDs NCs for colorimetric analysis of GSH. Moreover, Fe3+ can be detected through the fluorescence quenching of CuS@CDs NCs based on the inner filter effect (IFE). The results show the detection limits toward GSH and Fe3+ as low as 0.0527 μM and 0.0163 μM, respectively. In order to realize the detection of GSH and Fe3+ in the coexisting system, hydrogen peroxide is added into the system to reduce the mutual interference between GSH and Fe3+. The sensing strategy reaches wider linear GSH detection range of 0–500 μM in the coexisting system. The serum samples are successfully analyzed, suggesting the feasibility of sensing strategy. This sensing platform provides a new pathway for multicomponent biodetection in the coexisting system.