In Situ Bioimaging Of Lactobacillus By Photoluminescence Of Mos2

Due to unique properties arising from its 2D nature, molybdenum disulfide (MoS2) has been studied widely toward its application for biosensing. While MoS2 field effect transistor has been utilized for electrical detection of biological events in many studies, photoluminescence (PL) characteristics of MoS2 have been poorly employed. MoS2 PL can provide not only information of interactions between biological moieties and the surface, but also their spatial distribution. In this work, we utilized PL of single-layer MoS2 as a label-free bioimaging sensor. To fabricate the imaging device, we synthesized MoS2 by chemical vapor deposition and transferred it on a glass substrate with patterned electrodes. We employed Lactobacillus known as a probiotic microorganism to demonstrate the ability of bioimaging. We found that the MoS2 PL can be modulated by the concentration of lactic acid. Finally, we succeeded in monitoring PL image of MoS2 modulated by Lactobacillus, which can be correlated with the production of lactic acid by Lactobacillus.