Gold Nanoparticle Synthesis by Apoferritin Conjugated-antibody in Detecting Vibrio Cholera

Background and purpose: Synthesis of homogeneous and equally important nanoparticles is very popular in various sciences. Preparation and use of gold nanoparticles is very important according to their applications in biotechnology. For synthesizing homogeneous gold nanoparticles many substrates and nanostructures have been used. This study aimed at synthesis of gold nanoparticles by apoferritin to be conjugated to antibody for detection of vibrio cholera. Materials and methods: In this study, gold nanoparticles were prepared in apoferritin and compared with apoferritin free gold nanoparticles. Data were characterized by UV-Vis, DLS, and FE-SEM spectroscopy. Results: Findings showed that the synthesized gold nanoparticles in apoferritin are more homogeneous. Conclusion: The distribution of synthesizing gold nanoparticle in presence of apoferritin was so homogenous. In the following step, gold nanoparticles were separated from apoferritin and conjugated to recombinant antibody for detecting vibrio cholera. By bacteria aatchment on gold nanoparticles, red shift ocured on wavelength, which was also visible to naked eyes. So, gold nanoparticles could be considered as a colored biosensor for detection of vibrio cholera

NOVEL FREE LABEL BOTULINUM APTASENSOR BASED ON CAPACITANCE METHOD

A feasible and fast method to fabricate Botulinum neurotoxin serotype A (BoNT/A) biosensor was investigated by graphene-carbon paste nanocomposite electrode. In the present work, the graphene was synthesis by chemical method and characterized by SEM. The nanocomposite shows a high conductive and sensitivity for BoNT/A determination as shown by cyclic voltammetry and electrochemical impedance spectroscopy. Graphene-Carbone paste electrode was used for immobilization of aptamer in 0.1 M phosphate buffer solution at pH = 7. Aptamer was trapped in graphene modified carbon paste (Cp) electrodes. The electrodes were applied as indicator electrodes for capacitance determination of BoNT/A. Through this method, BoNT/A was detected in a concentration range from 0.16 to 0.68 ng·mL-1 with a correlation coefficient of 0.964 and detection limit of 0.09 ng·mL-1. Also, the life time of sensor is in finite

An Investigation of Immunogenicity of Chitosan-Based Botulinum Neurotoxin E Binding Domain Recombinant Candidate Vaccine via Mucosal Route

Background and Objectives: Botulism syndrome is caused by serotypes A-G of neurotoxins of Clostridium genus. Neurotoxin binding domain is an appropriate vaccine candidate due to its immunogenic activity. In this study, the immunogenicity of chitosan-based botulinum neurotoxin E binding domain recombinant candidate vaccine was investigated via mucosal route of administration. Methods: In this experimental study, chitosan nanoparticles containing rBoNT/E protein were synthesized by ionic gelation method and were administered orally and intranasally to mice. After each administration, IgG antibody titer was measured by ELISA method. Finally, all groups were challenged with active botulinum neurotoxin type E. Data were analyzed using Duncan and repeated ANOVA tests. The significance level was considered as p<0.05. Results: After each administration, IgG antibody titre was increased in all the test groups (except the control group). According to the results of challenge with active botulinum neurotoxin type E, the mice immunized orally and intranasally by nanoparticles containing the antigen and also the mice that only received the antigen orally, could tolerate 500 folds of LD50. The group immunized intranasally with only antigen tolerated 2000 folds of LD50. Conclusion: The results of this research showed that use of chitosan nanoparticles has no significant increase in the immunogenicity of recombinant botulinum neurotoxin antigen in oral and intranasal routes (p>0.05), even intranasal route reduced the immunogenicity