Fiber-optic singlet oxygen [1O2 (1Delta(g))] generator device serving as a point selective sterilizer

Area of Science:

• Photochemistry
• Biotechnology
• Materials Science

Background:

• Type II photo-oxidations traditionally require external light and oxygen.
• Singlet oxygen (SO) is a reactive species with antimicrobial potential.
• Existing methods for SO generation can be cumbersome.

Purpose of the Study:

• To develop an improved, portable device for internal singlet oxygen generation.
• To assess the efficacy of this device for microbial inactivation.

Main Methods:

• A hollow-core fiber-optic device with an integrated photosensitizer was designed.
• Internal light and oxygen supply facilitated SO generation at the fiber tip.
• N-benzoyl-DL-methionine trapping quantified SO concentration.
• Escherichia coli inactivation was tested in aqueous samples.

Main Results:

• The device delivered singlet oxygen through a maneuverable fiber tip.
• Steady-state SO concentration near the tip was approximately 20 fM.
• Complete inactivation of Escherichia coli (0.1-4.4 x 10^7 cells/mL) was achieved in 2 hours.
• The probe tip showed photobleaching after ~12 hours of use.

Conclusions:

• The developed fiber-optic device offers an efficient and portable method for internal singlet oxygen generation.
• The device demonstrated significant antimicrobial efficacy against Escherichia coli.
• Further optimization for probe longevity and reuse is needed.