Dual ligand–capped gold nanoclusters for the smart detection of specific reactive oxygen species

Quantitative detection of different types of reactive oxygen species (ROS) is vital for understanding the crucial roles of them in biological processes. However, few researches achieved the detection of multiple types of ROS with one probe until now. Given this, we designed and prepared fluorescent gold nanoclusters capped by dual ligand bovine serum albumin and lysozyme (BSA-LYS-AuNCs), which could detect 3 specific types of ROS based on its different fluorescent responses to H₂O₂, •OH and ClO⁻, respectively. The limit of detection (LOD) of H₂O₂, •OH, and ClO⁻ was as low as 0.82 μM, 0.45 μM, and 0.62 μM. Moreover, as an important ROS type, ClO⁻ was detected with high sensitivity and low LOD by BSA-LYS-AuNCs. It was also proved that the crosslinking of protein mainly contributed to the unique fluorescent characteristics of the probe exposing to ClO⁻. Furthermore, the fluorescent probe achieved the smart detection of hROS (including •OH and ClO⁻) and wROS (the form of H₂O₂) in the real sample, which could also been applied specifically to the detection of antioxidants, e.g. ascorbic acid. The gold nanoclusters developed have high potential for the smart detection of multiple ROS in the body fluid of organisms. Graphical abstract: [Figure not available: see fulltext.].