title: Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles.
abstract: Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ~90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens.
authors.affiliation: Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Eui-Seok
authors.initials: ES
authors.lastname: Chong
authors.forename: Gi Byoung
authors.initials: GB
authors.lastname: Hwang
authors.forename: Chu Won
authors.initials: CW
authors.lastname: Nho
authors.forename: Bo Mi
authors.initials: BM
authors.lastname: Kwon
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Sungchul
authors.initials: S
authors.lastname: Seo
authors.forename: Gwi-Nam
authors.initials: GN
authors.lastname: Bae
authors.forename: Jae Hee
authors.initials: JH
authors.lastname: Jung
mesh_terms: D061808:Air Filters; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology*; D047188:Chalcones / Q000032:analysis / Q000494:pharmacology; D004867:Equipment Design; D004926:Escherichia coli / Q000187:drug effects; D044950:Flavanones / Q000032:analysis / Q000494:pharmacology; D005419:Flavonoids / Q000032:analysis / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D039821:Monoterpenes / Q000032:analysis / Q000494:pharmacology; D053758:Nanoparticles; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D029909:Sophora / Q000737:chemistry*; D013212:Staphylococcus epidermidis / Q000187:drug effects; D013696:Temperature
chemical_list: D000890:Anti-Infective Agents; D047188:Chalcones; D044950:Flavanones; D005419:Flavonoids; D039821:Monoterpenes; D010936:Plant Extracts; C554822:kuraridin; C411319:kurarinone; C064849:vexibinol