Fluorescent Block Copolymer-MoS2 Nanocomposites for Real-Time Photothermal Heating and Imaging

Abstract

Novel self-monitoring photothermal (PT) agents are developed using optothermally responsive block copolymer-MoS2 composites (BCP-MoS2), which enable simultaneous PT heating and imaging of temperature profiles. In particular, upon near-infrared light exposure, PT energy from MoS2 successfully increases local temperature and induces thermally activated conformational transitions of the BCP on MoS2. This leads to fluorescent signal changes caused by distance-dependent Forster resonance energy transfer between the BCP and MoS2. Importantly, it is demonstrated that the use of BCP-MoS2 for PT heating and optical mapping is fully reversible with excellent stability. The detailed mechanism of the responsive behavior of BCP-MoS2 is elucidated by measurements of time-resolved fluorescence and dynamic light scattering. In addition, the BCP-MoS2 system is integrated into organogel matrices to demonstrate its potential as aportable, self-monitoring PT system suitable for biological and environmental applications.