Amino-rich silicon quantum dots as efficient activator with intrinsic chemiluminescence for the detection of peroxydisulfate.

The specific detection of peroxydisulfate (S₂O₈^2-, PDS) is significant and challenging due to the rapid development of PDS-related technologies and their widespread application in multiple fields. However, traditional analytical methods are mainly based on their strong oxidizing properties, making it difficult to simultaneously achieve specific identification and high sensitivity for PDS detection in complex water environments. Here, we purposely prepared amino-rich SiQDs (N-SiQDs) as an effective catalyst and introduced H₂O₂ acts as a co-reactant for PDS activation and determination with strong intrinsic chemiluminescence (CL) emission. High yield of reactive active oxygen (mainly O₂˙^- and ˙OH) were generated during CL process, which trigger electron-hole annihilation between the N-SiQDs˙⁺ and N-SiQDs˙^- accounted for extraordinary CL emission. On this basis, a new CL assay for PDS detection was fabricated with broad linear range of 5 × 10^-7M-5 × 10^-5 M and low detection limit (3.2 × 10^-7 M). Due to the absence of SO₄˙^- involvement during CL emission, the sensing platform is sensitive enough, satisfactory selectivity and does not respond to transition-metal ions and inorganic anions that have interferences in the PDS CL sensors reported before. This work not only deepens insight into the mechanisms of nanomaterials assisted PDS activation but also provides a new perspective on the modified metal-free QDs CL probe for chemical species detection.