The intensity of fluorescence is another important property that may be significantly affected by electrostatic environments. As shown in Figure , the intensity changes greatly with different solvent polarities, especially in the low-polarity regime. In contrast, only negligible changes are observed when applying OEEFs (refer to Figure , Figure , and Figure ). Specifically, the emission maximum is redshifted from 412 nm in vacuum to 453 nm in water, accompanied with a substantial intensity enhancement of 99% (0.211 vs 0.106 in water and in vacuum, respectively). On the contrary, when F X = -0.0050 a.u. is applied, although the emission maximum has been redshifted to 479 nm the intensity only decreases by 4% (0.102 vs 0.106 under F X = -0.0050 a.u. and F X = 0.0000 a.u., respectively). Overall, these contrasting observations indicate that the intensity tuning mechanisms induced by polar solvents and OEEFs are fundamentally different.