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| Author(s): |
Caio Henrique Nasi de Barros
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Química |
| Defense date: | 2017-07-11 |
| Examining board members: |
Ljubica Tasic;
Pedro Paulo Corbi;
Sandra Regina Ceccato Antonini
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| Advisor: | Ljubica Tasic |
| Abstract | |
Biogenic silver nanoparticles (AgNPs) or elemental silver in the nanometric scale obtained in a biogenic or biomimetic manner, have interesting physicochemical properties and an elevated antimicrobial activity. Using aqueous extracts of fresh or dry orange (Citrus sinensis) peel, biosynthesis of these nanoparticles were successfully executed in 10-12 h. The synthesis using fresh orange peel resulted in a higher yield (83%), and the nanoparticles were stabilized with proteins that were identified by mass spectrometry (UPLC-MS/MS). These AgNPs have an average diameter of 48,1 ± 20,5 nm and zeta potential around -20 mV. Also, through chemical and biomimetic synthesis, utilizing natural products extracted from orange waste, hesperidin (reducing agent) and nanocellulose (stabilizing agent), stable and uniform AgNPs were obtained. Their properties of average diameter and zeta potential were 25,4 ± 12,5 nm and -30 mV, respectively. A nanocellulose film was impregnated with AgNPs obtained through the chemical route, resulting in a paper of nanocellulose and nanosilver. All the AgNPs (three types) presented bacteriostatic and bactericide effects against Xanthomonas axonopodis pv. citri (Xac strain 306), the phytopathogen responsible for the citrus canker disease in orange plantations, in concentrations of 20-30 ?g/mL. Finally, an agrochemical formulation containing AgNPs was proposed, thus enabling future tests in orange plantations affected by the citrus canker (AU) | |
| FAPESP's process: | 15/12534-5 - Study on the supramolecular interactions in Silver Nanoparticles and their antimicrobial activity |
| Grantee: | Caio Henrique Nasi de Barros |
| Support Opportunities: | Scholarships in Brazil - Master |