Synthesizing Carbon Nanodots for Longer Wave Quantum Emission in Biological Applications

Carbon quantum dots are activated carbon particles with a size of 1–10 nm that have unique properties such as stable temperature, high stability in the environment, and special chemical properties. Their emission spectrum is always wide and towards long wavelengths with a sharp decrease in intensity. In this work, carbon quantum dots with long emission wavelengths and productivity improvements for biological applications are investigated. In order to reduce the experiments and obtain the best method, the experiment is designed with a mini fever and screened between different factors. In addition, complete factorial screening is performed between three factors (time, OPDA, and ALCL3) and the results demonstrated that time factor and OPDA are more effective. Using a UV–vis fluorescence device, the samples were examined and with the software (Origin Probe), the diagrams of each sample are drawn and their quantum efficiency is recorded. Quantum efficiency is evaluated at 575 nm and 618 nm. Then, the TEM test examined the synthesized nanoparticles’ size. The average particle size synthesized in this project is reported to be about 3 nm. The effect of synthesized carbon quantum dots on fibroblast cells is investigated and the results demonstrated that the survival of these cells after 24 h of incubation with synthesized carbon dots could be more than 90%. As a result, these nanoparticles can be used in biological applications such as bioimaging as a diagnostic sensor for methylene blue. On the other hand, it was found that the nanoparticles synthesized in the presence of HCL have higher strength and wavelength.