Ecenofloxacin hydrochloride

Constructing a dedicated S-scheme heterojunction photocatalytic system emerges as a credible method for developing high-performance photocatalysts. In this work, a plasmonic S-scheme heterojunction Ag/AgBr/Bi₂₄O₃₁Cl₁₀ photocatalyst was prepared using a facile in situ precipitation-photoreduction method. The obtained composites exhibited excellent photocatalytic performance for the elimination of enrofloxacin (EFA). Among them, 10 wt% Ag/AgBr/Bi₂₄O₃₁Cl₁₀ (ABBOC-2) demonstrated the optimal performance, degrading 85.7 % of EFA within 90 min. Furthermore, the ABBOC-2 composite achieved a 69.8 % total organic carbon (TOC) removal rate within 120 min, indicating substantial mineralization. A neutral reaction environment was found to be most conducive for high degradation efficiency. In addition, various cations inhibited EFA degradation to different extents, with NH₄⁺ showing the strongest suppression. Based on analysis of the degradation pathways, EFA was found to be decomposed mainly through three major routes: ring-opening cleavage, defluorination, and hydroxylation. The TEST toxicity prediction and the E. coli plate counting assay together confirm that the constructed photocatalytic system significantly reduces the toxicity of EFA. Radical trapping tests and electron spin resonance (ESR) spectroscopy verified that •O₂^-, •OH, and h⁺ all contributed to EFA degradation. Combined multiple characterization techniques with density functional theory (DFT) calculations, the charge transfer in Ag/AgBr/Bi₂₄O₃₁Cl₁₀ was shown to follow a typical S-scheme heterojunction mechanism. This work provides useful guidance for the rational design of novel plasmonic S-scheme heterojunction photocatalysts.

Antibiotic contamination is an emerging threat in marine environments due to its potential to alter key physiological processes in non-target organisms. Among veterinary antibiotics, enrofloxacin (ENR), a widely used fluoroquinolone, is frequently detected in coastal waters. This study investigated the biological effects of ENR exposure in the Mediterranean mussel Mytilus galloprovincialis using an integrated approach combining gene expression, biochemical, and bioenergetic endpoints. Mussels were exposed to two environmentally relevant concentrations of ENR (5 and 500 ng/L) for 7 days (EXP7) and 14 days (EXP14), followed by a 14-day recovery period (REC). Gill tissues were analyzed for transcriptional changes in genes related to detoxification, oxidative stress, apoptosis, and energy metabolism. In addition, energy reserves, mitochondrial activity, and indicators of genotoxicity and antioxidant responses were measured. Results showed that ENR exposure modulated the expression of several genes, including early upregulation of abcb and cyp4y1, and downregulation of pkpyr and icdh, indicating activation of detoxification pathways and energy metabolism shifts. Biochemical analyses revealed increased mitochondrial activity (ETS), mobilization of energy reserves, and sustained elevation of GST activity, while DNA strand break levels confirmed a potential genotoxic effect. Despite the removal of the contaminant, most stress responses did not fully revert during recovery. These findings demonstrate that even low concentrations of ENR can disrupt mussel physiology at multiple levels, with effects persisting beyond exposure. The study underscores the importance of incorporating sub-lethal biomarkers into environmental risk assessments and supports the inclusion of veterinary antibiotics like ENR in marine monitoring programs to protect coastal ecosystem health.