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Research Publications (Health Sciences)

Permanent URI for this collectionhttp://ir-dev.dut.ac.za/handle/10321/216

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Subject: search.filters.subject.Nanotechnology

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    African leafy vegetables as bio-factories for silver nanoparticles : a case study on Amaranthus dubius C Mart. Ex Thell
    (Elsevier, 2016) Sigamoney, M.; Shaik, S.; Govender, P.; Krishna, Suresh Babu Naidu
    Nanoparticles are used across many scientific and pharmaceutical fields and are found in products that come into close contact with the human body. There is a growing need for ‘green synthesis’ of silver (Ag) nanoparticles and plant-mediated synthesis is becoming increasingly popular. The current study aimed to firstly synthesise Ag nanoparticles using fresh and freeze-dried leaves, stems and roots of the African leafy vegetable, Amaranthus dubius. The synthesised Ag nanoparticles were subsequently characterised using UV–visible spectroscopy, scan-ning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) anal-ysis and Fourier transform infrared (FTIR) spectral analysis. The bioactivity (antibacterial and antifungal) of the synthesised Ag nanoparticles was also assessed using the minimum inhibition concentration (MIC) method. The results suggest that A. dubius plant extracts can serve as environmentally benign bio-factories for the synthe-sis of bioactive Ag nanoparticles. However, the characteristics of these nanoparticles differed based on the organ used to prepare the extract and whether the plant material was fresh or freeze-dried. Silver nanoparticle yield was greatest in the freeze-dried and fresh leaf extracts of A. dubius. However, EDX analysis revealed nanoparticles produced using freeze-dried and fresh stem extracts to contain the most elemental Ag. Silver nanoparticles syn-thesised from the different plant organs all displayed a spherical shape; however, Ag nanoparticles synthesised from the stem extracts (30–35 nm) were significantly larger than those synthesised from leaf and root extracts (18–21 nm). FTIR analysis confirmed the presence of carbonyl groups, proteins and aldehydes on nanoparticles produced using all extract types. The Ag nanoparticles synthesised from fresh stem extracts displayed the highest antimicrobial activity compared with those synthesised from the other plant organs. Fresh stem extracts of A. dubius appear to be most suitable for biosynthesis of Ag nanoparticles, yielding the largest nanoparticles, with the highest elemental Ag content, and greatest inhibition of microbial growth.
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    A desktop evaluation of the potential impact of nanotechnology applications in the field of environmental health in a developing country
    (Science and Education Publishing, 2015) Naidoo, Levani; Kistnasamy, Emilie Joy
    Nanotechnology is the latest addition to enhancing lifestyles of the human population. It also has an impact on the core parts that are vital to the well-being of humanity and its’ sustainability. Nanotechnology has been researched and is implemented in a number of countries at a commercialized level. However, in South Africa, nanotechnology is still being explored at grassroots with a few private industries implementing it. Based on research, the public health sector is expected to benefit the most from the application of nanotechnology. An environmental health practitioner plays a key role in ensuring the health and sustainability of the human population. The purpose of this desktop study is to generally explore the uses of nanotechnology in the Public Health sector with specificity to food, health and water remediation in the context of environmental health in South Africa and evaluate the possible impacts nanotechnology will have in the South African society. Proposed recommendations to be considered on how to address the use of nanotechnology in the current state of South Africa are made along with identifying the gaps in research in nanotechnology pertaining to South Africa.