SERS detection of trace nitrite ion in aqueous solution based on the nitrosation reaction of rhodamine 6G molecular probe

The stable reduced graphene oxide/triangular plate-type nanosilver aggregation/rhodamine 6G (rGO/TAgA/Rh6G) nanosensor exhibited a strong surface-enhanced Raman scattering (SERS) peak at 1505 cm−1 that was used to monitor the Rh6G concentration changes in the nitrosation reaction between Rh6G and NO2−, in which NO2− increase results in the SERS intensity decrease due to the decreasing Rh6G. The decreased SERS intensity was linear to nitrite concentration in the range of 0.7–72 nmol/L, with a detection limit of 0.2 nmol/L. Nitrite in water samples was analyzed by this Rh6G SERS nanosensor, with recovery of 94.8%–108% and relative standard deviation of 4.4%–7.5%.