Mechanistic Insights into the Fluorescence Quenching of Rhodamine 6G by Graphene Oxide

The fluorescence quenching of Rhodamine 6G （R6G） by graphene oxide （GO） was interrogated by R6G fluorescence measurements using a set of controlled GO samples with varied C/O ratios as the quencher. The carbonyl groups on the GO nanosheet turned to play a dominant role in quenching the R6G fluorescence. The quenching in the static regime can be described by the ＂sphere of action＂ model. The significant absorption of the R6G fluorescence by the ground-state complex formed between R6G and GO was identified to be responsible for the static quenching mechanisms in quenching. This work offers the R6G/GO system. insights into the fluorescence

Exploring the lentil protein and onion skin phenolics interaction by fluorescence quenching method

In this paper,the effect of two phenolic extracts(red and yellow onion skin,RS and YS respectively)with different phenolic profiles on the fluorescence quenching of lentil protein isolate(LPI)was investigated.The quenching effect of YS at 4–30μM concentrations on lentil proteins was in the range of 20.9–77.8%.A linear Stern-Volmer plot was obtained in agreement with static quenching for the LPI-YS complex while giving the blue shift at maximum emission between 8 and 30μM YS concentrations.Thermodynamic parameters of the LPI-YS complex showed that the interaction was hydrophobic(ΔH>0 andΔS>0),enthalpy driven(ΔH>ΔS),and non-spontaneous(ΔG>0)reaction.RS provided a more effective quenching effect at lower concentrations compared to YS and the quenching effect of RS at 1–16μM concentrations was 24.5–92.8%.On the other hand,the red shift was observed between 0 and 16μM RS concentrations,where the Stern-Volmer plot was non-linear,so there was a“sphere of action model”for LPI-RS complexes.