Gold Nanorod-Decorated Metallic MoS2 Nanosheets for Synergistic Photothermal and Photodynamic Antibacterial Therapy.

Dyah Ika Krisnawati,Fajar Rinawati,Hengky Irawan,Pei-Feng Chung,Heny Kristanto,Chinmaya Mutalik,Sibidou Yougbaré,Tsung-Rong Kuo

doi:10.3390/nano11113064

Abstract

Light-responsive nanocomposites have become increasingly attractive in the biomedical field for antibacterial applications. Visible-light-activated metallic molybdenum disulfide nanosheets (1T-MoS2 NSs) and plasmonic gold nanorods (AuNRs) with absorption at a wavelength of 808 nm were synthesized. AuNR nanocomposites decorated onto 1T-MoS2 NSs (MoS2@AuNRs) were successfully prepared by electrostatic adsorption for phototherapy applications. Based on the photothermal effect, the solution temperature of the MoS2@AuNR nanocomposites increased from 25 to 66.7 °C after 808 nm near-infrared (NIR) laser irradiation for 10 min. For the photodynamic effect, the MoS2@AuNR nanocomposites generated reactive oxygen species (ROS) under visible light irradiation. Photothermal therapy and photodynamic therapy of MoS2@AuNRs were confirmed against E. coli by agar plate counts. Most importantly, the combination of photothermal therapy and photodynamic therapy from the MoS2@AuNR nanocomposites revealed higher antibacterial activity than photothermal or photodynamic therapy alone. The light-activated MoS2@AuNR nanocomposites exhibited a remarkable synergistic effect of photothermal therapy and photodynamic therapy, which provides an alternative approach to fight bacterial infections.

Highlights

IntroductionPhotoresponsive nanomaterials have been extensively applied for energy conversion, electronic devices, and medical therapies [1,2,3,4,5,6,7,8]
The optical properties of 1T-MoS2 NSs, aqueous solution rods (AuNRs), and MoS2 @AuNRs were first characterized by UV–Vis spectroscopy
Band broadening of the longitudinal surface plasmon resonance (SPR) bands of AuNRs was observed in MoS2 @1/3AuNRs, MoS2 @1/2AuNRs, and MoS2 @AuNRs

Summary

Introduction

Photoresponsive nanomaterials have been extensively applied for energy conversion, electronic devices, and medical therapies [1,2,3,4,5,6,7,8]. The use of light-activated nanomaterials has been focused on phototherapy [9,10,11,12,13,14,15,16]. Phototherapy is defined as the use of photoresponsive nanomaterials to generate heat or noxious components to kill microorganisms or cells [17,18,19]. Photothermal therapy is a treatment that utilizes photothermal agents activated by light irradiation. The absorbed light energy is transformed into heat by photothermal agents for therapeutic purposes [23,24,25]. Photothermal therapy was reported to induce no bacterial resistance, and it is effective

Methods

Results

Conclusion