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Enhanced Singlet Oxygen Production from Metal Nanoparticle Based Hybrid Photosensitizers

Ding, Rui
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447690607

Abstract Details

2016, PhD, University of Cincinnati, Arts and Sciences: Chemistry.
In this dissertation, we explored the syntheses and characterizations of water dispersible hybrid photosensitizers by combining metal nanoparticles and organic photosensitizers. In the first project, we reported a novel metal enhanced singlet oxygen production and fluorescence quenching phenomenon based on the conjugates between gold nanoparticles and rose bengal. When rose bengal covalently conjugated to the surface of average ~ 50 nm gold nanoparticles, the fluorescence was dramatically quenched; however, singlet oxygen production was implied to be enhanced by measuring its phosphorescence at ~ 1280 nm. Singlet oxygen quantum yield of the novel hybrid photosensitizer was calculated as to be 0.75 by using rose bengal as reference photosensitizer. In the second project, we discussed the employing of carboxylic modified silver nanoparticles, 6-mercaptohexanoic acid stabilized silver nanoparticles, to conjugate with toluidine blue O to form a novel hybrid photosensitizer. The silver nanoparticles were prepared by a modified Brust’s method with an average size ~ 5 nm. The covalent conjugation between silver and toluidine blue O quenched the fluorescence and enhanced the singlet oxygen production according to the spectroscopic results. The presence of singlet oxygen and the enhancement of singlet oxygen production were demonstrated by the photodecomposition of 1,3-diphenylisobenzofuran. Singlet oxygen quantum yield of the hybrid photosensitizer was calculated as 0.78. In the third project, thiol-modified amphiphilic block copolymer, poly(N-isopropylacrylamide-block-styrene), was synthesized and characterized. Then, a novel hybrid photosensitizer based on poly(N-isopropylacrylamide-block-styrene) stabilized silver nanoparticles and entrapped hydrophobic photosensitizer (hematoporphyrin) was prepared. The water dispersible hybrid photosensitizer demonstrated enhanced singlet oxygen production with broadened excitation profile by monitoring phosphorescence at ~1280 nm. The photodynamic inactivation of the hybrid photosensitizer on Staphylococcus epidermidis and Escherichia coli showed enhanced killing efficacy up to ~5 orders under white light or NIR light illumination. The hybrid photosensitizer with concentration used in photodynamic inactivation assays showed low toxicity to Hela cells under ambient light condition. Those results demonstrate great potential of such hybrid photosensitizers for photodynamic inactivation and photodynamic therapy applications. In summary, we stated the preparation and analyses of the three hybrid photosensitizers with potential application in photodynamic therapy.
Peng Zhang, Ph.D. (Committee Chair)
Hairong Guan, Ph.D. (Committee Member)
William Heineman, Ph.D. (Committee Member)
105 p.
Chemistry
singlet oxygen; metal nanoparticles; photosensitizer; photodynamic therapy

Recommended Citations

Citations

  • Ding, R. (2016). Enhanced Singlet Oxygen Production from Metal Nanoparticle Based Hybrid Photosensitizers [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447690607

    APA Style (7th edition)

  • Ding, Rui. Enhanced Singlet Oxygen Production from Metal Nanoparticle Based Hybrid Photosensitizers. 2016. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447690607.

    MLA Style (8th edition)

  • Ding, Rui. "Enhanced Singlet Oxygen Production from Metal Nanoparticle Based Hybrid Photosensitizers." Doctoral dissertation, University of Cincinnati, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447690607

    Chicago Manual of Style (17th edition)

ucin1447690607
306
© 2016, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.