Excited-State Electron and Energy Transfer Dynamics between 2D MoS2 and GO/RGO for Turn ON BSA/HSA Sensing

Abstract

We report excited-state electron and energy transfer processes from two-dimensional MoS2 to graphene oxide (GO) and reduced graphene oxide (RGO) and also extend its application toward turn ON sensing of bovine serum albumin (BSA) and human serum albumin (HSA). Steady-state fluorescence results reveal the quenching of MoS2 QDs by GO and RGO. The fluorescence quenching efficiency is found to be more in the presence of GO than with RGO. The obtained Stern–Volmer plot suggests the occurrence of both static and dynamic quenching processes. The electron transfers from photoexcited MoS2 QDs to GO and RGO cause reduction and electron storage reactions, respectively. Time-resolved fluorescence results show significant reduction in the lifetime of a fast decay component of MoS2 upon addition of GO and RGO, which provides evidence for the excited-state energy transfer interaction in addition to electron transfer between MoS2 and GO/RGO. The calculated nonradiative decay rate indicates that the energy transfer proces...