Ratiometric fluorescent sensors for nitrite detection in the environment based on carbon dot/Rhodamine B systems.

A novel carbon dot/Rhodamine B-based ratiometric fluorescent probe was developed for a highly sensitivity and selective detection of nitrite (NO 2 - ). The probe showed colour changes from blue to orange under ultraviolet light in response to NO 2 - with a detection limit as low as 67 nM in the range of 0 to 40 μM. A ratiometric fluorescent test paper was successfully prepared using the probe solution, which demonstrated its feasibility towards a rapid and semi-quantitative detection of NO 2 - in real samples.