Cluster-Assembled Hollow SnO ₂ Spheres as Biomimetic Enzymes for Ultrasensitive Electrochemical Detection of Superoxide Anions

High Resolution Image Download MS PowerPoint Slide Electrochemical sensing of superoxide anions (O 2 • – ) has garnered substantial attention in biomedical and environmental monitoring due to the critical role of this reactive oxygen species in physiological and pathological processes. This study constructed a biomimetic electrochemical detection platform composed of cluster-assembled hollow SnO 2 spheres (SnO 2 HS) for the detection of O 2 • – . Cluster-assembled SnO 2 HS was prepared by the hard template method using SiO 2 spheres as templates. The diameter of SnO 2 HS is approximately 50 nm, and the spherical shell is composed of 5 nm SnO 2 clusters. This biomimetic catalyst exhibits the best response to O 2 • – at a relatively low operating potential of 0.7 V, featuring a response time of 1.5 s, a detection limit of 0.06 nM, and a linear range of 0.2–900 nM. Moreover, this material shows a robust anti-interference capability toward small biomolecules (hydrogen peroxide, urea, uric acid, hydroxylamine hydrochloride, ascorbic acid, dopamine, glucose) and metal ions (K +, Na +, Zn 2+, Ni 2+, Fe 3+, Fe 2+, Cu 2+, Co 2+ ), none of which interfere with the detection of O 2 • – . Hence, cluster-assembled SnO 2 HS as a biomimetic electrochemical sensing material shows great promise for detecting O 2 • – released by cells during the wound healing process, laying a foundation for the design and development of new electrochemical sensing materials.