Beyond bottom-up carbon nanodots: Citric-acid derived organic molecules

Citrate‐Based Fluorescent Biomaterials

“…Employing a one-pot synthesis strategy, the obtained citrate-based CDs typically had polydispersed structures, including small molecules, oligomers, polymer chains, polymer clusters and carbon cores. [13, 14, 25, 26] Song et al systematically studied the components of CDs synthesized from CA and ethylenediamine (EDA). [25] They separated the CDs reacted at 140 °C by column chromatography on silica, and obtained 5 batches of fluorescent components.…”

“…The molecular fluorophores mainly contain five or six-membered heterocyclic structures, which could be dissociated freely in solution or be connected on the surface and even interior of the carbon backbone. [26] When the synthesis proceeds to a higher temperature or longer time, the molecular fluorophores can be further dehydrated and/or carbonized to form polymer structures and carbon cores. Generally, the molecule state can easily be distinguished due to its unique characteristics, including a characteristic Gaussian peak in UVevis spectra, and excitation-independent fluorescence emission.…”

“…[16–20] Researchers have proposed that the fluorescence performance of citrate-based CDs can be attributed to both their carbon cores and small molecular fluorophores. [21–26] Furthermore, Yang’s group developed a family of citrate-based biomaterials, [27, 28] among which a set of biodegradable photoluminescent polymers (BPLPs) were developed due to the great potential of CA to form fluorescent molecules in reaction with amino acids. [29, 30] BPLPs demonstrated in vitro cytocompatibility, minimal in vivo chronic inflammatory responses, controlled degradability, desired mechanical properties, excellent processability for micro/nano fabrication, as well as strong and adjustable fluorescence.…”

Manipulating the Optical Properties of Carbon Dots by Fine‐Tuning their Structural Features

“…The excitation wavelength was increasedf rom 250 to 530 nm in 20 nm increments. [11,36,[42][43][44][45][46] Thist rend in F is an indicatoro ft he strong impact of chemical treatment on the optical properties of HTC-CDs. [16,[37][38][39][40] Therefore, PL quantum yields F were recorded with 370 nm excitation versus ar eference solution of quinines ulfate.…”

Carbogenically coated silica nanoparticles and their forensic applications

“…Alternatively, Cdots with varying graphitization degree are derived through disintegration 14 , hydrothermal treatment 15 and electrooxidation 16 of carbon nanotubes, carbon nanofibers and graphite. In principle, quantum yield can be improved via surface passivation 17 , heteroatom doping18 and the in situ formation of organic chromophores 19,20 .…”