Bioinspired carbon dots (biodots): emerging fluorophores with tailored multiple functionalities for biomedical, agricultural and environmental applications

Nature provides abundant resources to support life on our planet. In particular, biological systems possess unique properties and functions such as bio-recognition and self-assembly, which makes them an attractive inspiration for mankind to design smart materials at the molecular level. This review reports an emerging class of bioinspired fluorescent nanodots (biodots) derived from natural resources ranging from small biomolecules, biopolymers to biomass for a wide spectrum of technological applications. These "biodots" are carbonaceous in nature with inherent biocompatibility, which can be molecularly engineered to obtain both biological and physiochemical properties in one entity similar to the molecular machines in cells. Importantly, the surface properties and functionalities of biodots can be fine-tuned depending on the types of precursors used in their synthesis. This mini-review summarises the recent development of fluorescent biodots with intrinsic biological and/or biomimetic functions, with an aim to examine their formation mechanisms and understand how different types of precursors affect the overall properties of biodots. This is followed by a thorough discussion on the successful utilizations of these biodots for biomedical (e.g., theranostic agents), agricultural (e.g., fertilizers for plant growth) and environmental (e.g., pollutant detection) applications, in order to gain critical insights into the molecular design of multifunctional biodots tailored for different applications. Lastly, we highlight the promising directions and future outlook of biodots with the aid of artificial intelligence, which will potentially accelerate the development of this promising field.