Effect of number of positive charges on the photophysical and photodynamic therapy activities of quarternary benzothiazole substituted zinc phthalocyanine
- Authors: Matshitse, Refilwe , Nwaji, Njemuwa , Mananga, Muthumuni , Prinsloo, Earl , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187819 , vital:44700 , xlink:href="https://doi.org/10.1016/j.jphotochem.2018.08.033"
- Description: The synthesis, photophysicochemical and photodynamic therapy (PDT) activity of quaternary benzothiazole substituted zinc phthalocyanine (2, containing two charges, and 3, containing four charges) are reported in this work. Furthermore, the activity of the synthesized complex was compared to non-quaternary derivative (1). Higher triplet and singlet oxygen quantum yields of 0.92 and 0.85, respectively, for quaternized complexes 2 and 3 compared to complex 1 alone. Complexes 1, 2 and 3 showed relatively no dark toxicity against the epithelial breast cancer cells with cell survival of above 90 ± 3%. The quaternary derivatives (2 and 3) showed superior PDT activity with 30% or less of viable cells at concentration of 50.0 μg/mL in comparison to complex 1 alone which further lay credence to the importance of quaternization in the enhancement of PDT activity.
- Full Text:
- Date Issued: 2018
Electrocatalytic activity of a push-pull phthalocyanine in the presence of reduced and amino functionalized graphene quantum dots towards the electrooxidation of hydrazine
- Authors: Centane, Sixolile , Sekhosana, Kutloana E , Matshitse, Refilwe , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233456 , vital:50092 , xlink:href="https://doi.org/10.1016/j.jelechem.2018.05.005"
- Description: We report on the electrochemical behaviour of reduced graphene quantum dots (rGQDs) compared to amino functionalized graphene quantum dots (NH2GQDs). Reduction of the GQDs entails the elimination of the excessive carboxyl and hydrogen groups on the GQDs surface, thereby reducing the energy band gap. The energy band gap of graphene is directly proportional to the available oxygen atoms. The two GQD types were conjugated to a novel cobalt phthalocyanine (cobalt tris-(tert-butyl phenoxy)-mono-carboxyphenoxy phthalocyanine, CoPc) via covalent and nom-covalent interactions. The resulting conjugates were tested towards the electrooxidation of hydrazine. The conjugates are represented as rGQDs(π)CoPc, NH2(π)CoPc, rGQDs@CoPc and NH2GQDs@CoPc. The resulting conjugates were adsorbed onto a glassy carbon electrode using the drop and dry method. The lowest limit of detection (LOD) was obtained for rGQDs(π)CoPc.
- Full Text:
- Date Issued: 2018