Metallophthalocyanines: versatile probes for microbial photoinactivation and for pollutant degradation as photocatalysts, both molecular or supported form
- Authors: Sindelo, Azole
- Date: 2024-10-11
- Subjects: Phthalocyanines , Active oxygen , Nanoparticles , Nanofibers , Glass wool , Photocatalysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466614 , vital:76760 , DOI https://doi.org/10.21504/10962/466614
- Description: This thesis investigates the synthesie of metallophthalocyanines for potential use as photosensitizers in two applications: photodynamic antimicrobial chemotherapy and the photodegradation of organic pollutants. To achieve this, phthalocyanines with morpholine (substituted at alpha and beta position, to imine), ethyl and propyl pyrrolidine Schiff bases, asymmetrical mercaptobenzothiazole and morpholine substituents were synthesized for the first time. All nitrogen containing phthalocyanines were methylated to form cationic derivatives. Asymmetrical mercaptobenzothiazole were covalently linked to spherical and pyramidal zinc oxide nanoparticles, while the asymmetrical morpholine were conjugated to polyacrylonitrile (PAN) nanofibers, chitosan modified PAN and glass wool, while carboxylic acid containing phthalocyanines were also linked to glass wool. Various characterization techniques, including electronic spectroscopy, mass spectroscopy, nuclear magnetic resonance (NMR), Fourier-transform infrared (FT-IR), elemental analysis, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscope (SEM), and time-resolved fluorescence measurements were employed to characterize all the phthalocyanine composites. The research aimed to establish general trends in fluorescence quantum yields, triplet and singlet oxygen generation, photodegradation rates, and fluorescence and triplet state lifetimes of the complexes. Notably, the presence of zinc oxide nanoparticles increased the triplet quantum yield of phthalocyanines, however, the singlet oxygen quantum yield decreased. The study also examined the photodynamic inactivation of various planktonic cells and biofilms using all photosensitizers. The photodynamic antimicrobial chemotherapy activities were dose-dependent, and all cationic photosensitizers were highly effective in completely inactivating the microbes in both forms, as opposed to non-charged photosensitizers. For the supports, the chitosan modified PAN showed high efficacy due to improved hydrophilicity. Furthermore, the research was conducted on the photodegradation of 4-chlorophenol, methyl orange and methylene blue using Pc-anchored PAN and glass wool supports. The immobilized photosensitizers demonstrated a strong capacity for generating singlet oxygen in aqueous media, with the cationic Pc-PAN removing methylene blue more efficiently due to its adsorption and photodegradation abilities. All supports were recoverable, showing potential application for future use in the removal of microbes and organic pollutants. , Thesis (PhD) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Sindelo, Azole
- Date: 2024-10-11
- Subjects: Phthalocyanines , Active oxygen , Nanoparticles , Nanofibers , Glass wool , Photocatalysis
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/466614 , vital:76760 , DOI https://doi.org/10.21504/10962/466614
- Description: This thesis investigates the synthesie of metallophthalocyanines for potential use as photosensitizers in two applications: photodynamic antimicrobial chemotherapy and the photodegradation of organic pollutants. To achieve this, phthalocyanines with morpholine (substituted at alpha and beta position, to imine), ethyl and propyl pyrrolidine Schiff bases, asymmetrical mercaptobenzothiazole and morpholine substituents were synthesized for the first time. All nitrogen containing phthalocyanines were methylated to form cationic derivatives. Asymmetrical mercaptobenzothiazole were covalently linked to spherical and pyramidal zinc oxide nanoparticles, while the asymmetrical morpholine were conjugated to polyacrylonitrile (PAN) nanofibers, chitosan modified PAN and glass wool, while carboxylic acid containing phthalocyanines were also linked to glass wool. Various characterization techniques, including electronic spectroscopy, mass spectroscopy, nuclear magnetic resonance (NMR), Fourier-transform infrared (FT-IR), elemental analysis, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscope (SEM), and time-resolved fluorescence measurements were employed to characterize all the phthalocyanine composites. The research aimed to establish general trends in fluorescence quantum yields, triplet and singlet oxygen generation, photodegradation rates, and fluorescence and triplet state lifetimes of the complexes. Notably, the presence of zinc oxide nanoparticles increased the triplet quantum yield of phthalocyanines, however, the singlet oxygen quantum yield decreased. The study also examined the photodynamic inactivation of various planktonic cells and biofilms using all photosensitizers. The photodynamic antimicrobial chemotherapy activities were dose-dependent, and all cationic photosensitizers were highly effective in completely inactivating the microbes in both forms, as opposed to non-charged photosensitizers. For the supports, the chitosan modified PAN showed high efficacy due to improved hydrophilicity. Furthermore, the research was conducted on the photodegradation of 4-chlorophenol, methyl orange and methylene blue using Pc-anchored PAN and glass wool supports. The immobilized photosensitizers demonstrated a strong capacity for generating singlet oxygen in aqueous media, with the cationic Pc-PAN removing methylene blue more efficiently due to its adsorption and photodegradation abilities. All supports were recoverable, showing potential application for future use in the removal of microbes and organic pollutants. , Thesis (PhD) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
Synthesis of indium phthalocyanines for photodynamic antimicrobial chemotherapy and photo-oxidation of pollutants
- Authors: Sindelo, Azole
- Date: 2019
- Subjects: Phthalocyanines , Azo dyes , Indium compounds , Photochemotherapy , Nanoparticles , Photodegradation , Pollutants , Water -- Purification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67581 , vital:29116
- Description: Indium (III) octacarboxyl phthalocyanine (ClInOCPc) alone and when conjugated to magnetic nanoparticles (MNP-ClInOCPc), 2(3),9(10),16(17),23(24)-octapyridylsulfanyl phthalocyaninato chloroindium (III) (ClInOPyPc) and its quaternized derivative 2(3),9(10),16(17),23(24)-octamethylpyridylsulfanyl phthalocyaninato chloroindium (III) (ClInOMePyPc) were synthesized. All Pcs were tested for both photodynamic antimicrobial chemotherapy (PACT) of an unknown water sample and photo-degradation of methyl red (MR). The singlet quantum yield (ΦΔ) for the ClInOCPc and MNP-ClInOCPc in PAN polymer fibers were 0.36 and 0.20 respectively using ADMA as a quencher in water. The photo-inactivation of bacteria in a water sample with unknown microbes was tested, with the MNP-ClInOCPc inactivating 90.6 % of the microbes and the ClInOCPc with 84.8 %. When embedded to the polymer, there was 48% bacterial clearance for ClInOCPc and 64% clearance for the MNP-ClInOCPc. The rate of degradation of MR increased with decrease of the MR concentration, with the MNP-ClInOCPc having the fastest rate. For ClInOPyPc and ClInOMePyPc, the singlet quantum yields were 0.46 and 0.33 in dimethylformamide (DMF), respectively. The PACT activity of ClInOMePyPc (containing 8 positive charges) was compared to those of 9(10),16(17),23(24)-tri-N-methyl-4-pyridylsulfanyl-2(3)-(4-aminophenoxy) phthalocyaninato chloro indium (III) triiodide (1) (containing 3 positive charges) and 2-[4-(N-methylpyridyloxy) phthalocyaninato] chloroindium (III) iodide (2) (containing 4 positive charges). When comparing ClInOMePyPc, 1 and 2, the largest log reduction for E. coli were obtained for complex 2 containing four positive charges hence showing it is not always the charge that determines the PACT activity, but the bridging atom in the phthalocyanine plays a role.
- Full Text:
- Date Issued: 2019
- Authors: Sindelo, Azole
- Date: 2019
- Subjects: Phthalocyanines , Azo dyes , Indium compounds , Photochemotherapy , Nanoparticles , Photodegradation , Pollutants , Water -- Purification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67581 , vital:29116
- Description: Indium (III) octacarboxyl phthalocyanine (ClInOCPc) alone and when conjugated to magnetic nanoparticles (MNP-ClInOCPc), 2(3),9(10),16(17),23(24)-octapyridylsulfanyl phthalocyaninato chloroindium (III) (ClInOPyPc) and its quaternized derivative 2(3),9(10),16(17),23(24)-octamethylpyridylsulfanyl phthalocyaninato chloroindium (III) (ClInOMePyPc) were synthesized. All Pcs were tested for both photodynamic antimicrobial chemotherapy (PACT) of an unknown water sample and photo-degradation of methyl red (MR). The singlet quantum yield (ΦΔ) for the ClInOCPc and MNP-ClInOCPc in PAN polymer fibers were 0.36 and 0.20 respectively using ADMA as a quencher in water. The photo-inactivation of bacteria in a water sample with unknown microbes was tested, with the MNP-ClInOCPc inactivating 90.6 % of the microbes and the ClInOCPc with 84.8 %. When embedded to the polymer, there was 48% bacterial clearance for ClInOCPc and 64% clearance for the MNP-ClInOCPc. The rate of degradation of MR increased with decrease of the MR concentration, with the MNP-ClInOCPc having the fastest rate. For ClInOPyPc and ClInOMePyPc, the singlet quantum yields were 0.46 and 0.33 in dimethylformamide (DMF), respectively. The PACT activity of ClInOMePyPc (containing 8 positive charges) was compared to those of 9(10),16(17),23(24)-tri-N-methyl-4-pyridylsulfanyl-2(3)-(4-aminophenoxy) phthalocyaninato chloro indium (III) triiodide (1) (containing 3 positive charges) and 2-[4-(N-methylpyridyloxy) phthalocyaninato] chloroindium (III) iodide (2) (containing 4 positive charges). When comparing ClInOMePyPc, 1 and 2, the largest log reduction for E. coli were obtained for complex 2 containing four positive charges hence showing it is not always the charge that determines the PACT activity, but the bridging atom in the phthalocyanine plays a role.
- Full Text:
- Date Issued: 2019
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