Highly sensitive and selective fluorescent detection of vitamin D3 in human serum using carbon quantum...

This study explores the use of carbon quantum dots (CQDs), aptamers (Apt), and nanographite (NG) for fluorescent sensing of vitamin D. CQDs-Apt conjugates adsorb onto the surface of NG via π-π stacking interactions, inducing an internal filter effect (IFE) that quenches the intrinsic fluorescence of the CQDs-Apt complex. In the presence of vitamin D, this internal filter effect is disrupted, resulting in the recovery of fluorescence from the CQDs-Apt conjugates. The sensor exhibits a linear response range from 0 to 900 nM with a detection limit of 20.87 nM (calculated using the 3σ method). Importantly, this sensor has been successfully applied to detect vitamin D in blood samples. Furthermore, the aptamer sensors based on carbon quantum dots can effectively distinguish the interfering substances in serum. This technology offers advantages such as high sensitivity, selectivity, simplicity of operation, thus opening new avenues for the development of vitamin sensing platforms.