In the present study, green synthesised ZnO nanoparticles using Calotropis gigantea (C. gigantea) leaf extract which were produced at different calcination temperatures (i.e. 400 C and 500 C) were evaluated against skin ulcer pathogens since no study is reviewed before. The results from x-ray powder diffraction and energy-dispersive spectroscopy confirmed the presence of ZnO nanoparticles along with natural compounds from medicinal plant (i.e. Ca and C). The capping and stabilising phytochemical agents of C. gigantea leaves such as phenol and carbonyl were identified through UV–Vis and FTIR. Scanning electron microscopy and transmission electron microscopy revealed that increasing the calcination temperature altered the size and shape of the prepared samples. ZnO nanoparticles which were prepared at calcination temperatures of 400 C and 500 C were quasi-spherical and irregular rod in shape. The minimum inhibitory and the minimum bactericidal concentrations of ZnO-400C were 0.625 and 1.25 mg ml⁻¹, whereas those of ZnO-500C were 1.25 and 20 mg ml⁻¹ against Staphylococcus aureus (S. aureus). Remarkably, the ZnO-400C revealed excellent bactericidal activity against skin ulcer pathogens, with MBC ranging from 0.3125 mg ml⁻¹ to 2.5 mg ml⁻¹. The time-kill kinetics assay demonstrated that 1.25 mg ml⁻¹ ZnO-400C captured a significant reduction of ≤2.5 log₁₀ in the S. aureus population after 6 h of incubation. ZnO-400C sample significantly reduced the biofilm formed by S. aureus which might be associated to the presence of Zn²⁺, Ca²⁺ and reactive oxygen species (ROS). A strong interaction and exfoliation between natural calcium and carbon from C. gigantea and ZnO nanoparticles offered new insights to inactivate skin ulcer pathogens synergically.

在本研究中，使用在不同煅烧温度（即 400 C 和 500 C）下生产的Calotropis gigantea ( C. gigantea ) 叶提取物合成的绿色 ZnO 纳米颗粒针对皮肤溃疡病原体进行了评估，因为之前没有研究过。X 射线粉末衍射和能量色散光谱的结果证实了 ZnO 纳米颗粒以及来自药用植物的天然化合物（即 Ca 和 C）的存在。C. gigantea的加帽和稳定植物化学剂通过 UV-Vis 和 FTIR 鉴定了苯酚和羰基等叶子。扫描电子显微镜和透射电子显微镜显示，提高煅烧温度会改变所制备样品的尺寸和形状。在400℃和500℃的煅烧温度下制备的ZnO纳米颗粒呈准球形和不规则棒状。ZnO-400C 的最低抑菌浓度和最低杀菌浓度分别为 0.625 和 1.25 mg ml ^-1，而 ZnO-500C的最低抑菌浓度和最低杀菌浓度分别为 1.25 和 20 mg ml ^-1对金黄色葡萄球菌（S. aureus）。值得注意的是，ZnO-400C 对皮肤溃疡病原体显示出优异的杀菌活性，MBC 范围为 0.3125 mg ml ^-1至 2.5 毫克毫升^-1。时间杀伤动力学分析表明，1.25 mg ml ^-1 ZnO-400C在S 中捕获了≤2.5 log ₁₀的显着降低。孵育 6 小时后的金黄色葡萄球菌种群。ZnO-400C 样品显着减少了金黄色葡萄球菌形成的生物膜，这可能与 Zn ²⁺、Ca ²⁺和活性氧 (ROS) 的存在有关。来自C. gigantea 的天然钙和碳与 ZnO 纳米颗粒之间的强烈相互作用和剥落为协同灭活皮肤溃疡病原体提供了新的见解。