Cadmium oxide (CdO) had long been investigated for decades as prototypical wide-band-gap transparent conducting oxides (TCOs) possessing excellent n-type ability having its implications in the field of photo electronics. Despite this, there exists an uncertainty on the toxicity of CdO content during the synthesis and product retrieval which limits their use in biological applications. In this context, an approach to enhance the inbuilt properties of CdO particles by the means of loading (in coating form) with gold (Au) nanoparticles (NPs) to generate Au@CdO nanoconstructs (NCs) has been reported. Thus, formed Au@CdO NCs have been characterized by various spectroscopic and electron microscopic analysis for the structural, optical, and biological properties. For example, the UV–Vis spectroscopy revealed a typical λ_max of CdO at 302 nm, and for the Au@CdO, a shift toward 496 nm was observed. The diffraction pattern demonstrated the crystalline phase corresponding to (1 1 1) plane with mean grain sizes of 24.9 and 30.6 nm for the CdO and Au@CdO, respectively. The FTIR and optical studies highlighted the intermolecular bonding with an increased bandgap confirming the efficient coating of Au onto CdO. The FESEM demonstrated spherical-to-elliptical-shaped anisotropic particles following the coating of CdO with Au and the grain size getting increased from 30 to 42 nm. On testing of the photocatalytic activity, we found that the Au@CdO NCs efficiently degraded the Rhodamine B dye (96% in 180 min) following the irradiation under artificial UV light. Furthermore, the Au@CdO NCs showed a significant antimicrobial effect at 80 μg/mL associated with a decline in the cell count. Alongside, the IC₅₀ of Au@CdO against A549 and PBMC cells was fixed at 46.87 and 55.14 μg/mL, respectively. Such multifaceted Au@CdO NCs possessing optical properties might present themselves as the potential candidates for the extended photocatalytic and biomedical applications.

Graphic abstract

中文翻译：

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轻松制造具有可调整性质的Au负载CdO纳米结构，用于光催化和生物医学应用

氧化镉（CdO）已被研究数十年，因为其典型的宽带隙透明导电氧化物（TCO）具有出色的n型能力在光电子学领域具有重要意义。尽管如此，在合成和产物回收过程中CdO含量的毒性仍存在不确定性，这限制了其在生物应用中的使用。在这种情况下，已经报道了通过以金（Au）纳米颗粒（NP）加载（以涂层形式）以生成Au @ CdO纳米结构（NC）的方式来增强CdO颗粒的内在性能的方法。因此，已形成的Au @ CdO NCs已通过各种光谱和电子显微镜分析对其结构，光学和生物学特性进行了表征。例如，UV-Vis光谱揭示了典型的λ_最大在302nm处的CdO为100nm，对于Au @ CdO，观察到向496nm的偏移。衍射图谱表明，对应于（1 1 1）平面的晶相的CdO和Au @ CdO的平均晶粒尺寸分别为24.9和30.6 nm。FTIR和光学研究突出显示了带隙增加的分子间键合，证实了Au在CdO上的有效涂层。FESEM证明，在用Au涂覆CdO之后，球形到椭圆形的各向异性颗粒就会出现，并且晶粒尺寸从30 nm增加到42 nm。在测试光催化活性时，我们发现在人工紫外线照射下，Au @ CdO NCs有效降解了若丹明B染料（180分钟内96％）。此外，Au @ CdO NCs在80μg/ mL处显示出显着的抗菌作用，与细胞计数下降相关。同时，IC针对A549和PBMC细胞的₅₀ AuCdO分别固定为46.87和55.14μg/ mL。这种具有光学特性的多面Au @ CdO NCs可能会成为扩展的光催化和生物医学应用的潜在候选者。

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