Photoluminescent carbon dot sensor for carboxylated multiwalled carbon nanotube detection in river water

A simple, rapid and efficient luminescent method based on carbon dots (CDs) as nanosensor of carboxylated multiwalled carbon nanotubes (c-MWCNTs) has been developed for the first time. Luminescent CDs were successfully synthesized by making use of bottom-up methodology without the need of further surface passivation, obtaining the highest quantum yield (QY: 19%) for cellulose microcrystalline as precursor. This simple and economic preparation of luminescent CDs was accompanied by an evaluation of their ability for detecting c-MWCNTs in water owing to the formation of hydrogen bond interactions. The limits of detection (LOD) and quantification (LOQ) for c-MWCNTs were 0.37 and 1.25 μg mL−1, respectively. The proposed sensing method was validated in spiked river water, demonstrating its potential in environment water samples.