Browsing by Author "Naumih, Noah"

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    Antibacterial activity of green synthesized silver nanoparticles using Citrullus lanatus fruit rind extract
    (Kenya Chemical Society, 2020) Ndikau, Michael; Naumih, Noah; Andala, Dickson; Masika, Eric
    The increased resistance of microbes to current antibiotics calls for development of new effective antimicrobial agents. Metal nanoparticles such as silver nanoparticles have continued to attract increased research interest in the recent past because of their wide range of applications such as in the areas of chemical sensing, nanomedicine and electronics. In this work, spherical AgNPs (17.96 ± 0.16 nm in diameter) synthesized via a green method using Citrullus lanatus (water melon) fruit rind extract were evaluated for antimicrobial activity against clinical isolates of Escherichia coli (E.coli) and Salmonella typhi (S.typhi) bacteria using the discdiffusion method. The Minimum Inhibition Concentration (MIC) value of the nanoparticles was found to be 45.00 ± 0.01 g/ml for S.typhi and 38.50 ± 0.00 g/ml for E.coli while the Minimum Bactericidal Concentration (MBC) value was found to be 60.00 ± 0.05 g/ml for S.typhi and 50.00 ± 0.00 g/ml for E.coli. This study demonstrated that these two bacterial strains were susceptible to the green synthesized AgNPs.
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    Development of an Electrochemical Nano-biosensor for Rapid and Sensitive Diagnosis of Bilharzia in Kenya
    (sabinet, 2018) Odundo,Joseph; Naumih, Noah; Andala,Dickson; Kiragu,Janet; Masika,Eric
    Bilharzia, also known as schistosomiasis, is still affecting more than 250 million people, killing about 200 000 annually and leaving millions of others debilitated. Current diagnostic tools have extremely low validity and are not readily applicable for rapid diagnosis in rural and remote areas. In low-grade infections, microscopy, the most commonly used method, may have low sensitivity. For example, in suspected cases, up to five real sample specimens are recommended for increased sensitivity. The rise of nanotechnology has created the potential to significantly improve the current diagnostic approaches. Conjugating antibodies with nanoparticles pools the distinctive properties of the nanoparticles with the specificity and selectivity of the antibodies in the recognition of the antigen. This in return leads to a very versatile and specific mixed product with improved analytical signal which is important for fast, sensitive and real-time point-of-care diagnosis. In this work, we report the use of nanotechnology to develop a simple and sensitive nano-biosensor which consisted of a nano-strip with immobilized gold nanoparticles conjugated with bilharzia antibody, and demonstrated its potential for diagnosis of bilharzia antigen. A detection range of 1.13 × 101 ng mL–1 to 2.3 × 103 ng mL–1 of bilharzia antigen in stool samples and with a limit of detection of 8.3887 × 10–2ng mL–1 was attained, indicating the potential of the nano-biosensor to be used to detect bilharzia antigen in stool samples.