Self-assembled albumin decorated MoS2 aggregates and photo-stimuli induced geometrical switching for enhanced theranostics applications

Abstract

2D materials such as graphene oxide and molybdenum sulfide exhibit certain properties such as photoluminescence, photothermal and photodynamic effects that have potential in diagnosing and treating cancer. However, their application is limited by low cellular uptake of the sheet-like structure. In this study, we present a facile route for converting MoS₂ sheets into cotton-candy like aggregates which are then internalized easily by cells and then disassembled into sheets. Initially MoS₂ sheets are produced from bulk MoS₂ by albumin assisted exfoliation followed by assembly of sheets into aggregates by a desolvation technique. The MoS₂ cotton-candy like aggregates can be taken up by cells more easily when compared to sheets because of low colloidal stability. Using a near infrared laser, the aggregates can be disintegrated into sheets within the cells. Two processes take place in this step. First, the photothermal properties of MoS₂ aggregates can be used to kill cancerous cells. Secondly, on disintegration, the photoluminescence properties of MoS₂ sheets can be utilized to image cancer cells. The cytotoxicity, phototoxicity and apoptosis of HeLa cells are reported here. A facile method for increasing the uptake of 2D materials into cells has been demonstrated.