Recent advances in green carbon dots (2015–2022): synthesis, metal ion sensing, and biological applications

Abstract

Carbon dots (CDs) show extensive potential in various fields such as sensing, bioimaging, catalysis, medicine, optoelectronics, and drug delivery due to their unique properties, that is, low cytotoxicity, cytocompatibility, water-solubility, multicolor wavelength tuned emission, photo-stability, easy modification, strong chemical inertness, etc. This review article especially focuses on the recent advancement (2015–2022) in the green synthesis of CDs, their application in metal ions sensing and microbial bioimaging, detection, and viability studies as well as their applications in pathogenic control and plant growth promotion.

Realizing High Performance Tunable Sensing Mode and Selectivity of Metal Ions Based on Carbon Dot

“…Indeed, we speculated such significant difference in the selectivity of metal ions among our synthesized CDs on variation in binding affinity due to the amount and types of functional groups present. [54,55] In point of fact, all these results evidenced that our tailored CDs from A. donax, a natural reservoir, are highly ultrasensitive and selective. They have excellent potential in identifying degree of contamination in water resource by metal ions even at low levels.…”

“…Thus, CD2 solution shows highly fluorescent selectivity to Cr +6 ions among all the tested metal ions in aqueous medium. Indeed, we speculated such significant difference in the selectivity of metal ions among our synthesized CDs on variation in binding affinity due to the amount and types of functional groups present [54,55] . In point of fact, all these results evidenced that our tailored CDs from A. donax , a natural reservoir, are highly ultrasensitive and selective.…”

Plant-based carbon dots are a sustainable alternative to conventional nanomaterials for biomedical and sensing applications

“…Unique optical and chemical properties that can reshape the landscape of nanotechnology [8,9]. The journey of plant-based CDs begins with their facile synthesis from various plant sources, such as tulsi, coriander, aloe vera, turmeric, and more [10,11]. These plants serve as natural precursors rich in phytocompounds, allowing for the creation of non-toxic CDs with inherent therapeutic properties [12,13].…”

Psidium guajavaderived carbon nanoparticles: A promising red emissive cellular bioimaging agent

“…This approach offers a facile and costeffective strategy for producing CNPs from biomass as a carbon source, as it is both environmentally friendly and naturally accessible when compared to alternative carbon sources 2 . The use of this natural biomass as a low-value resource can convert it into a valuable material, offering advantages such as high availability, low cost, eco-friendly, and renewability 3 . Numerous researchers have investigated the green synthesis of carbon nanoparticles (CNPs) utilizing plant resources as a precursor, instead of using chemical compounds, due to the sustainability of such an approach and the presence of heteroatoms, such as nitrogen, sulfur, boron, and phosphorus 3 .…”

“…The use of this natural biomass as a low-value resource can convert it into a valuable material, offering advantages such as high availability, low cost, eco-friendly, and renewability 3 . Numerous researchers have investigated the green synthesis of carbon nanoparticles (CNPs) utilizing plant resources as a precursor, instead of using chemical compounds, due to the sustainability of such an approach and the presence of heteroatoms, such as nitrogen, sulfur, boron, and phosphorus 3 . The presence of chlorophyll within green leaves, which possess porphyrin structures, results in substantial near-infrared (NIR) absorption and emission.…”