Main agent orange-red coloured pigment of henna is a molecule called Lawson which is responsible for anti-microbial, anti-tumor, anti-inflammatory and analgesic activity. Chitosan is a biopolymer with high strength, biocom-patibility and biodegradability, non-toxicity and antimicrobial properties. Electrospinning is a method of producing su-bmicron polymeric fibers with high porosity and high surface/volume ratio. In this study, electrospinning of chitos-an/polyethylene oxide (Chit/PEO) nanofibers with the addition of henna extract to create nanofibers with antimicrobial properties were examined. Nanofibers was constructed by electrospinning of polymeric solution with proper size and si-ze distribution of Chit/PEO with a ratio 90/10. Then, Lawsonia inermis (henna) extract as an additive to Chit/PEO co-polymer was added and electrospined on the surface. After characterization of nanofibers using SEM, the antimicrobial properties of polymeric solution and nanofibers were investigated. The scanning electron micrographs showed that Ch-it/PEO nanofibres with a low percentage of henna extract have suitable diameters and size distribution similar to Ch-it/PEO nanofibres without adding extract. In bacteriological studies, it was found that chitosan polymer solutions cont-aining 1% of henna extract has bactericidal properties against Staphylococcus aureus, Escherichia coli and Pseudo-monas aeruginosa bacteries better than polymer chitosan solution without adding the extract.

Tetanus is caused by the toxin secreted by Clostridium tetani. Due to the rapid infection with this bacterium, it is so important to investigate the tetanus immunity of people. Therefore, electrochemical biosensors, as one of the most effective tools in this regard, have demanded characteristics such as being fast, simple, cost-effective and portable. However, their detection sensitivity is not sufficient. Hereon, silver enhancement of gold-nanoparticles was proposed for the improvement of detection. Hence, the current study applied gold-nanoparticles as label, following with silver enhancement, to investigate the yes/no electrochemical detection of anti-tetanus toxoid antibodies in the indirect immunoassay utilizing glassy-carbon electrodes modified by carbon nanotubes. The analytical procedure consists of the reactions of the tetanus toxoid with the antibody at electrode, so that followed by the interaction of gold-labeled secondary antibody and then silver enhancement process. In this study, the cyclic-voltammeter variation and difference of gold to silver signal based on silver ions fluctuations were also investigated. The results indicated that ∆E_p increased from 0.24 V before silver enhancement reaction to 0.57 V after the silver enhancement. The results also demonstrated that after silver enhancement, current significantly increased and current plot at E^c_p transferred to positive potentials and at E^a_p moved to negative potentials. In conclusion, this method increases the detection sensitivity and can simply use to other bio-molecules detection.