Two-dimensional materials for improved resolution in total internal reflection fluorescence microscopy

We propose and theoretically demonstrate that two-dimensional materials at the interface between glass and water layers in a total internal reflection fluorescence microscopy (TIRFM) technique can decrease the detection volume of a target sample, and hence improve the resolution of the obtained image. In particular, we calculate the change in fluorescence characteristics of the fluorophore labels on a target sample when monolayer black phosphorus, hexagonal boron nitride, and graphene are added at the glass-water interface of a TIRFM structure. We also calculate the change in the detection volume due to the presence of two-dimensional materials, and when the polarization, wavelength, and angle of the incident light vary. We find $\gtrsim $ 10% and $\gtrsim $ 5% decrease in the detection volume when monolayer black phosphorus and hexagonal boron nitride are used, respectively, and up to  ~50% decrease when monolayer graphene is used. The proposed use of the two-dimensional material will significantly improve the resolution of TIRFM technique, and hence facilitate the study of nanoscale biological features.