Development of Green-Yellow Fluorescent Boron-Doped Carbon Dots as a Base Structure for Future Construction of Potential Cancer Theranostic Nanoplatform

Cancer is one of the diseases with the highest mortality rate worldwide. Recent studies have shown that different types of nanoparticles, such as carbon dots (CDs), are promising candidates in applications against cancer due to their physical-chemical properties. Moreover, CDs have a high load capacity to integrate with heteroatoms or drugs through doping and functionalization. Here we report the synthesis and characterization of undoped CDs (uCDs) and boron-doped CDs (B-CDs). They were synthesized in a one-step, microwave-assisted reaction at 200 ℃, using citric acid as the carbon source, and four different amino acids were evaluated as nitrogen precursors. Additionally, boric acid was used as the boron precursor for synthesizing B-CDs, obtaining nanoparticles that exhibit green-yellow fluorescence. MTT assay showed that both, uCDs and B-CDs are biocompatible exhibiting viability rates of over 80% after 24 h in HT29, 3T3-L1, U87, and VERO cell lines. The obtained results represent an excellent opportunity to apply these developed B-CDs as cancer theranostic nanoagents and bioimaging probes. In particular, its boron content as a dopant makes them a promising alternative for boron neutron capture therapy (BCNT).