Fluorescent nanostructures based on carbon, or carbon dots, are attracting much attention and interest because of their diverse properties which can be applied in several fields of knowledge, such as optics, biomedicine, environmental research, among others. Such properties are in part, derived from its intrinsic luminescence from tunable functional groups. In this work, we produced carbon nanodots (CND) using agro-industrial residues, such as Lolium perenne and malt bagasse. The methods used were conventional hydrothermal syntheses and microwave-assisted hydrothermal synthesis. To the best of our knowledge, this is the first time that carbon dots synthesized from this ryegrass type are reported. The synthesis methods were one step (no catalyst, base, or acid were added for passivation), and the functional groups responsible for the luminescence and high solubility in water were identified by infrared spectroscopy, being mainly C=O, C–OH, C–N, and N–H. According to our theoretical studies, the C=O group introduced a new energy level for electronic transitions that can affect the emission properties. Fluorescence images of osteoblasts using CNDs were acquired and their chelating property towards Pb²⁺ and Cr⁶⁺ detection was tested.

基于碳或碳点的荧光纳米结构因其多样的特性而备受关注和兴趣，这些特性可应用于多个知识领域，如光学、生物医学、环境研究等。这些特性部分来自可调官能团的固有发光。在这项工作中，我们使用农用工业残留物生产碳纳米点 (CND)，例如多年生黑麦草和麦芽甘蔗渣。使用的方法是常规水热合成和微波辅助水热合成。据我们所知，这是首次报道由这种黑麦草合成的碳点。合成方法为一步法（不加催化剂、碱或酸钝化），红外光谱鉴定出负责发光和高水溶性的官能团，主要为C=O、C-OH、C –N 和 N–H。根据我们的理论研究，C=O 基团为电子跃迁引入了一个新的能级，可以影响发射特性。获得了使用 CND 的成骨细胞的荧光图像，并测试了它们对 Pb ²⁺和 Cr ⁶⁺检测的螯合特性。