Nanotechnology has become one of the most important topics since the beginning of the twenty-first century in numerous fields including drug synthesis and delivery, environmental protection, electronics manufacture, and astronomy due to their nanoscale particles and their properties. The traditional semi-quantum dots are replaced by a new category of fluorescent carbon nanomaterials. Carbon dots (CDs) have been explored in the last few years for their simple synthetic accession, good bio-consonance, and several revelation applications. This review explains the fluorescent properties of CDs in brief, giving also a background on CDs discovery, structure, and composition, as well as on nanocomposites, green synthesis, and their applications. Resources conservation can be achieved by using recycled substances for sustainable development which lead to a new technology. Fluorescent CDs synthesized from food wastes like bananas, orange peel waste, sugarcane bagasse, Trapa bispinosa peels, bread, and jaggery have several applications such as sensing, drug delivery, gene transfer, biological imaging, and food safety. In this study, we concentrate on CDs greener methods to prepare effective and biocompatible CDs.

中文翻译：

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碳点：发现，结构，荧光性质和应用

自二十世纪初以来，由于纳米技术的纳米级颗粒及其特性，纳米技术已成为许多领域（包括药物合成和输送，环境保护，电子制造和天文学）中最重要的主题之一。传统的半量子点被一类新的荧光碳纳米材料所取代。碳点（CD）在过去的几年中一直被研究，因为它们具有简单的合成成分，良好的生物谐和性以及一些启示性的应用。这篇综述简要地解释了CD的荧光特性，还为CD的发现，结构和组成以及纳米复合材料，绿色合成及其应用提供了背景知识。通过使用可循环利用的物质来实现新技术，可以实现资源节约。由诸如香蕉，橙皮废料，甘蔗渣，蔗糖，面包和粗糖等食物废料合成的荧光CD具有多种应用，例如传感，药物递送，基因转移，生物成像和食品安全。在这项研究中，我们将重点放在CD的绿色方法上，以制备有效且生物相容的CD。