High Quantum Yield Boron and Nitrogen Codoped Carbon Quantum Dots with Red/Purple Emissions for Ratiometric Fluorescent IO₄^– Sensing and Cell Imaging

Abstract

A facile and cost-effective hydrothermal method was developed for the preparation of boron and nitrogen codoped carbon quantum dots (B,N-CQDs) from 3-carboxyphenylboronic acid and o-phenylenediamine. The synthesized B,N-CQDs exhibit excellent properties such as excellent water solubility, strong fluorescence, good dispersion, and desirable stability. The average particle size of B,N-CQDs is 2.82 nm, and the absolute fluorescence quantum yield is 86.58%. The excitation wavelength of B,N-CQDs is 300 nm. Emission bands of B,N-CQDs appeared at 356 and 700 nm. Periodate (IO 4 − ) quenches B,N-CQDs emissions through chelation reaction. The ratio of F 356 / F 700 has a good linear relationship with the concentration of IO 4 − in the range of 0.01−40 μmol/L with the detection limit of 0.003 μmol/L. This method has the advantages of a low detection limit, high sensitivity, wide linear range, good selectivity, simplicity, and rapidness. It can be used as a ratiometric fluorescent probe for the detection of IO 4 − , and it was successfully applied in the analysis of IO 4 − in water. The cytotoxicity and biocompatibility of B,N-CQDs were evaluated and successfully applied in cell imaging.

Carbon dots using a household cleaning liquid as a dopant for iron detection in hydroponic systems

“…17,55 Some groups have recently reported producing highly efficient CDs, with QY ranging from ∼70–90%. 56–58…”

“…17,55 Some groups have recently reported producing highly efficient CDs, with QY ranging from ∼70-90%. [56][57][58] The pH of hydroponic solutions affects the availability of certain nutrients. A lower pH (e.g., 5.5) will keep most nutrients in solution while a higher pH (e.g., >6.5) is likely to cause nutrient deprivation.…”

A review on characterization of carbon quantum dots

“…To ensure the change in lifetime of the CQDs, lifetime study of both CQDs and CQDs+H2O were performed and it was come spectroscopic results confirmed that the quenching process is dynamic one. [70][71][72][73] FRET Process: It is a phenomenon that occurs between the excited state of the CQDs and the ground state of the quencher which may be organic molecules or inorganic analytes. [74] This phenomenon is applied in huge scale in different fields to detect various organic molecules, biologically important molecules, pesticides or inorganic metal ions which may be very important in sense of toxicity.…”

Green and facile synthesis of silicon-doped carbon dots and their use in detection of Hg2+ and visualization of latent fingerprints

“…[18][19][20][21] With their distinguished properties and abundant surface functional groups, CDs have also become exemplary optical sensors for environmental water contaminants. [22][23][24] For instance, Meng et al developed boron-doped CDs via a one-step hydrothermal method, which were used for highly selective and ultrasensitive detection of Hg 2+ via a fluorescence quenching effect, and the B-CDs also exhibited satisfactory recovery in actual water samples. 25 Liu et al reported blue fluorescent nitrogen-doped CDs, which were fabricated using anhydrous citric acids and polyethyleneimine as precursors.…”