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Studies on gold nanoparticles for application in detection of aflatoxins in selected food commodities.

Abhijith, K. S. (2013) Studies on gold nanoparticles for application in detection of aflatoxins in selected food commodities. PhD thesis, University of Mysore.

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Abstract

Nanobiotechnological approach for the detection of toxins and pathogens for food safety has become an important field of research in recent years. Considering the vast potentials of nanoparticles as nano labels in biosensing, gold nanoparticle based immunosensing methodology development for mycotoxins was attempted keeping aflatoxin B1 as model mycotoxin. Gold nanoparticles were synthesized by different methods having diverse opto-physical properties. Antibodies against aflatoxin B1 was raised in avian system and used as biorecognition element. Antibodies generated showed high affinity towards aflatoxins (2.8x107 L/M) as confirmed by competitive ELISA. The anti aflatoxin IgY antibodies were bioconjugated with the synthesized gold nanoparticles. Further metal enhanced luminescence concept was studied in detail for biosensing application. Three different luminescence concepts viz. metal enhanced fluorescence (MEF), metal enhanced bioluminescence (MEB) and metal enhanced chemiluminescence (MEC) were studied. The enhancement of luminescence due to the presence of gold nanoparticles was two to ten folds with different methods. With the basic knowledge of metal enhanced luminescence concept, three different strategies for aflatoxin B1 detection were attempted. With MEF method, aflatoxin B1 detection limit was found to be 5 pg/mL whereas in enhanced chemiluminescence (EnCL) method it was 0.1 ng/g. Both the methods showed sensitivity limit well below the EU regulations for aflatoxins (2 ng/g). Further a field applicable semi quantitative dipstick method was developed for rapid screening of aflatoxins. Visual detection range for immunodipstick was found to be 1-200 ng. Further simulated real sample analysis was carried out using food samples like wheat flour and peanut butter. Both MEF and EnCL method showed intra and inter assay precision having RSD below 15%. The results clearly indicated the possibility of developing robust, field applicable immunosensor based on gold nanoparticles antibody bioconjugates for the detection of mycotoxins like aflatoxin.

Item Type: Thesis (PhD)
Uncontrolled Keywords: Nanobiotechnological approach, food safety, aflatoxin
Subjects: 600 Technology > 05 Chemical engineering > 01 Biotechnology and Bioengineering
600 Technology > 08 Food technology > 10 Food Microorganisms
Divisions: Fermentation Technology and Bioengineering
Depositing User: Food Sci. & Technol. Information Services
Date Deposited: 16 Mar 2015 12:29
Last Modified: 16 Mar 2015 12:29
URI: http://ir.cftri.com/id/eprint/11750

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