Biomass-Derived Carbon Dots as Nanoprobes for Smartphone-Paper-Based Assay of Iron and Bioimaging Application.

A facile one-step carbonization approach is reported herein for the sustainable hydrothermal synthesis of fluorescent blue nitrogen-doped carbon quantum dots (NCQDs) using banana petioles obtained as biomass waste. These NCQDs were used to design a "turn-off" fluorescent probe, which exhibited excellent sensing capability toward the selective detection of micronutrient, Fe ion, with a limit of detection (LOD) of 0.21 nM.