The present research describes the synthesis of cadmium sulfide (CdS) nanoparticles from Escherichia coli under the influence of bacterial enzyme sulphate reductase and study on their cytotoxicity for applications in cancer therapy. Escherichia coli cells were used to synthesize CdS nanoparticles under different concentrations of cadmium chloride and sodium sulfide. The morphology of the nanoparticles was analysed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) was used for elemental analysis of nanoparticles. Fourier-transform infrared spectroscopy analysis (FTIR) was performed to assess the functional groups of the nanoparticles. Crystalline nature of nanoparticles was assessed using powder X-ray diffraction (XRD). Antibacterial studies of CdS nanoparticles were carried out on foodborne pathogens and cytotoxicity studies were carried out on Mus musculus skin melanoma (B16F10) and human epidermoid carcinoma (A431) cell lines. CdS nanoparticle showed more cytotoxic effect on cancer cells compared with standard 5-aminolevulinic acid (5-ALA). The Escherichia coli-synthesized CdS nanoparticles showed highest zone of inhibition in the ratio 4:1 of cadmium chloride and sodium sulfide on all tested bacterial strains. The nanoparticles were also tested for haemolytic activity on RBC cells, which exhibited lower cytotoxicity than sodium dodecyl sulphate which was used as positive control. The cytotoxicity of CdS nanoparticles assessed on A431 cells showed an inhibition of 81.53% at 100 μM concentration while the cytotoxicity assessed on B16F10 cells showed an inhibition of 75.71% at 200 μM concentration which was much efficient than 5-ALA which showed an inhibition of 31.95% at a concentration against B16F10 cells and 33.45% against A431 cells at a concentration of 1 mM. Cadmium sulfide nanoparticles were thus found to be highly toxic on cancer cells compare with standard anticancerous drug 5-ALA.

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基于大肠杆菌的硫化镉纳米颗粒的合成、表征、抗菌和细胞毒性研究

本研究描述了在细菌酶硫酸还原酶的影响下从大肠杆菌中合成硫化镉 (CdS) 纳米粒子，并研究它们在癌症治疗中的细胞毒性。使用大肠杆菌细胞在不同浓度的氯化镉和硫化钠下合成硫化镉纳米颗粒。使用扫描电子显微镜 (SEM) 分析纳米颗粒的形态，并使用能量色散 X 射线光谱 (EDX) 进行纳米颗粒的元素分析。进行傅里叶变换红外光谱分析（FTIR）以评估纳米颗粒的官能团。使用粉末 X 射线衍射 (XRD) 评估纳米颗粒的结晶性质。对食源性病原体进行了 CdS 纳米颗粒的抗菌研究，并对小家鼠皮肤黑色素瘤 (B16F10) 和人表皮样癌 (A431) 细胞系进行了细胞毒性研究。与标准 5-氨基乙酰丙酸 (5-ALA) 相比，CdS 纳米颗粒对癌细胞显示出更多的细胞毒性作用。大肠杆菌合成的 CdS 纳米粒子在所有测试的细菌菌株上显示出最高的抑制区，氯化镉和硫化钠的比例为 4:1。还测试了纳米颗粒对红细胞的溶血活性，其表现出比用作阳性对照的十二烷基硫酸钠更低的细胞毒性。在 A431 细胞上评估的 CdS 纳米颗粒的细胞毒性显示抑制率为 81。在 100 μM 浓度下为 53%，而对 B16F10 细胞评估的细胞毒性显示在 200 μM 浓度下抑制率为 75.71%，这比 5-ALA 有效得多，5-ALA 在浓度下对 B16F10 细胞的抑制率为 31.95%，对 A431 细胞的抑制率为 33.45%浓度为 1 mM。因此，与标准抗癌药物 5-ALA 相比，硫化镉纳米颗粒对癌细胞具有高毒性。