Curvature strain engineering enhanced singlet oxygen selectivity: Dual-Function FeN4 sites for targeted guanine oxidation of antibiotic resistance genes.

Peroxymonosulfate (PMS)-based Fenton-like systems have emerged as a promising technology for extracellular antibiotic resistance gene (eARG) elimination in water remediation, yet the simultaneous realization of low oxidant dosage and high reactive oxygen species (ROS) selectivity remains a critical bottleneck hindering practical engineering applications. This study utilized nanodiamond with natural curvature as carriers to construct C-FeSAC catalysts. The geometric strain caused by surface curvature induces Fe 3d orbital splitting and spin rearrangement, triggering spin crossover and orbital state evolution, promoting an HS-to-MS spin-state evolution of the Fe centers. As versatile electron-transfer hubs, bifunctional FeN4 active sites accelerate the formation of critical C-FeSAC-O*(PMS) intermediates and modulate the pathway of dissolved oxygen activation. This dual regulatory behavior achieves highly selective, multi-pathway generation of singlet oxygen (1O2). Based on the specific oxidation of low ionization potential guanine by 1O2, the catalyst achieved 4.7 log degradation of eARGs within 30 min and markedly suppressed the transformation activity of treated eARGs. The constructed Al2O3 catalytic membrane system still exhibits efficient eARGs removal performance under high-throughput conditions. This study clarifies the geometric strain-mediated ROS regulation mechanism, providing a facile and feasible strategy for practical eARG pollution control in water treatment.