Cadmium‐Activated Cascade Sensing of Arginine Using an Azomethine‐Linked Silane With Enhanced Antioxidant Capability

ABSTRACT Developing efficient dual‐target chemosensors for the detection of toxic metal ions and biologically relevant amino acids remains a significant challenge. In this work, an azomethine‐linked silane (Compound 3 ) was designed, synthesized, and thoroughly characterized. Photophysical studies revealed that Compound 3 exhibits excellent sensitivity and selectivity toward Cd(II) ions. Furthermore, the in situ formed Compound 3 –Cd(II) complex exhibited selective recognition of arginine (Arg) over other competing amino acids, demonstrating its dual sensing capability. The sensor showed remarkable limits of detection, with 3.8 nM for Cd(II) and 0.4 μM for Arg, enabling detection well below environmental and biological safety thresholds. Practical applicability was validated through water sample analysis, which afforded high percentage recovery values. In addition, Compound 3 displayed significant free‐radical scavenging activity, as evaluated by the DPPH assay, highlighting its potential relevance in oxidative stress‐related biological applications.