High UV-Vis-NIR Light-Induced Antibacterial Activity by Heterostructured TiO2-FeS2 Nanocomposites

Abstract

Chinmaya Mutalik,1,* Yu-Cheng Hsiao,1,2,* Yi-Hsuan Chang,3 Dyah Ika Krisnawati,4 Moh Alimansur,4 Achmad Jazidie,5,6 Mohammad Nuh,7 Chia-Che Chang,8 Di-Yan Wang,8 Tsung-Rong Kuo1,3 1International PhD Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan; 2Graduate Institute of Biomedical Optomechatronics, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan; 3Graduate Institute of Nanomedicine and Medical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan; 4Dharma Husada Nursing Academy, Kediri, East Java 64114, Indonesia; 5Department of Electrical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia; 6Universitas Nahdlatul Ulama Surabaya, Surabaya 60111, Indonesia; 7Department of Biomedical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia; 8Department of Chemistry, Tunghai University, Taichung 40704, Taiwan*These authors contributed equally to this workCorrespondence: Di-Yan WangDepartment of Chemistry, Tunghai University, Taichung 40704, TaiwanTel [phone]Email [email protected] KuoGraduate Institute of Nanomedicine and Medical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, TaiwanTel [phone]Email [email protected]: Antibiotic resistance issues associated with microbial pathogenesis are considered to be one of the most serious current threats to health. Fortunately, TiO2, a photoactive semiconductor, was proven to have antibacterial activity and is being widely utilized. However, its use is limited to the short range of absorption wavelength.Methods: In this work, heterostructured TiO2-FeS2 nanocomposites (NCs) were successfully prepared by a facile solution approach to enhance light-induced antibacterial activity over a broader absorption range.Results: In TiO2-FeS2 NCs, FeS2 NPs, as light harvesters, can effectively increase light absorption from the visible (Vis) to near-infrared (NIR). Results of light-induced antibacterial activities indicated that TiO2-FeS2 NCs had better antibacterial activity than that of only TiO2 nanoparticles (NPs) or only FeS2 NPs. Reactive oxygen species (ROS) measurements also showed that TiO2-FeS2 NCs produced the highest relative ROS levels. Unlike TiO2 NPs, TiO2-FeS2 NCs, under light irradiation with a 515-nm filter, could absorb light wavelengths longer than 515 nm to generate ROS. In the mechanistic study, we found that TiO2 NPs in TiO2-FeS2 NCs could absorb ultraviolet (UV) light to generate photoinduced electrons and holes for ROS generation, including ⋅O2− and ⋅OH; FeS2 NPs efficiently harvested Vis to NIR light to generate photoinduced electrons, which then were transferred to TiO2 NPs to facilitate ROS generation.Conclusion: TiO2-FeS2 NCs with superior light-induced antibacterial activity could be a promising antibacterial agent against bacterial infections.Keywords: antibacterial agent, antibacterial mechanism, reactive oxygen species, light harvester, light-induced antibacterial activity

Keywords

• antibacterial agent
• antibacterial mechanism
• reactive oxygen species
• light harvester
• light-induced antibacterial activity