Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Querétaro, Instituto Politécnico Nacional, Qro. CP. 76090, Querétaro, México.
Appl Biochem Biotechnol. 2023 Jul;195(7):4148-4163. doi: 10.1007/s12010-023-04341-z. Epub 2023 Jan 19.
The use of cadmium sulfide nanoparticles (CdS-NPs) synthesized by fungi presents highly stable chemical and optical characteristics; this makes them a promising alternative for development of colorimetric methods for metal detection. Moreover, application of CdS-NPs is challenging due to the biological material used to carry out synthesis and coating is highly diverse; therefore, it is necessary to evaluate if such components are present in the biological material. Thus, the objective of this work was to detect metallic ions in synthetic water samples using CdS-NPs synthesized by the extract of Aspergillus niger. The conditions to produce fungal extracts were determined through a factorial design 2; additionally, biomolecules involved in metallic ions detection, synthesis, and coating of CdS-NPs were quantified; the studied biomolecules are NADH, sulfhydryl groups, proteins, and ferric reducing antioxidants (FRAP). CdS-NPs synthesized in this study were characterized by spectrophotometry, zeta potential, and high-resolution transmission electron microscopy (HRTEM). Finally, detection capacity of metallic ions in synthetic water samples was evaluated. It was proved that the methanolic extract of Aspergillus niger obtained under established conditions has the necessary components for both synthesis and coating of CdS-NPs, as well as detection of metallic ions because it was possible to synthesize CdS-NPs with a hexagonal crystalline structure with a length of 2.56 ± 0.50 nm which were able to detect Pb, Cr, and Fe at pH 4 and Co at pH 8.
真菌合成的硫化镉纳米粒子（CdS-NPs）的使用具有高度稳定的化学和光学特性；这使得它们成为开发金属检测比色法的有前途的替代品。此外，由于用于进行合成和涂层的生物材料高度多样化，因此 CdS-NPs 的应用具有挑战性；因此，有必要评估生物材料中是否存在这些成分。因此，本工作的目的是使用黑曲霉提取物合成的 CdS-NPs 检测合成水样中的金属离子。通过 2 因素设计确定了产生真菌提取物的条件；此外，还定量了参与金属离子检测、CdS-NPs 合成和涂层的生物分子；研究的生物分子是 NADH、巯基、蛋白质和铁还原抗氧化剂（FRAP）。本研究中合成的 CdS-NPs 通过分光光度法、ζ电位和高分辨率透射电子显微镜（HRTEM）进行了表征。最后，评估了合成水样中金属离子的检测能力。事实证明，在既定条件下获得的黑曲霉甲醇提取物具有合成和涂层 CdS-NPs 以及检测金属离子的必要成分，因为可以合成具有 2.56±0.50nm 长度的六方晶结构的 CdS-NPs，并且能够在 pH 4 下检测 Pb、Cr 和 Fe，以及在 pH 8 下检测 Co。
