Deep-Level Defect Enhanced Photothermal Performance of Bismuth Sulfide-Gold Heterojunction Nanorods for Photothermal Therapy of Cancer Guided by Computed Tomography Imaging

Abstract

Bismuth sulfide (Bi₂ S₃ ) nanomaterials are emerging as a promising theranostic platform for computed tomography imaging and photothermal therapy of cancer. Herein, the photothermal properties of Bi₂ S₃ nanorods (NRs) were unveiled to intensely correlate to their intrinsic deep-level defects (DLDs) that potentially could work as electron-hole nonradiative recombination centers to promote phonon production, ultimately leading to photothermal performance. Bi₂ S₃ -Au heterojunction NRs were designed to hold more significant DLD properties, exhibiting more potent photothermal performance than Bi₂ S₃ NRs. Under 808 nm laser irradiation, Bi₂ S₃ -Au NRs could trigger higher cellular heat shock protein 70 expression and more apoptotic cells than Bi₂ S₃ NRs, and caused severe cell death and tumor growth inhibition, showing great potential for photothermal therapy of cancer guided by computed tomography imaging.

Keywords: bismuth sulfide; computed tomography; gold; photothermal therapy; semiconductor defects.