Green Synthesis of Carbon Quantum Dots and Performance Optimization for Bioimaging

Abstract

The rapid development of nanotechnology has brought about many new types of material for biomedical use, and among them, fluorescent nanomers are the most outstanding, used as bio imaging materials. The conventional semiconductor quantum dots, as good as they look when it comes to the light show they produce, carry a weighty burden: because of the heavy metal inside them, they can cause real problems for living things and nature too. As a new type of quantum dots, carbon quantum dots (CQDs) exhibit good biocompatibility, low toxicity, high photostability and adjustable photoluminescence. Another big change is the creation of green synthesis methods. They use nature-based things that can grow again and are cheap. These things aren't harmful to other living things. They fit in with how sustainable chemistry works. This paper gives an overall summary on the green synthesis of CQDs with different precursors, such as fruit peels, plant leaves, food waste, hydrothermal method, microwave-assisted method, and pyrolysis and so on. Also examines key ways of improving its performance so as to make it suitable for use with high contrast bioimages. They can be heteroatom doped with nitrogen, sulfur, phosphorus, etc., to increase quantum yield through changing electronic band structure, passivation and functionalization to control emission wavelengths and give targeting function towards certain organelle or diseased cells, control synthesis process to become more robust in harsh bioconditions. Review talks about how these improved, greener CQDs get used properly in both test tubes and living creatures, showing their cool potential to be the newest kind of safe and good light-markers for checking sick people and making medical studies better. the shift toward making CQDs that are both sustainable and can be scaled up for producing really good nanotech materials moves us closer to bringing these things into use clinically, so doctors can make better images of patients that are safer and easier to understand.