An electrochemical sensor was prepared to detect nicotine by depositing copper nanoparticles (Cu NPs) on the surface of a glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes (MWNTs). The modified electrode was characterized by scanning electron microscopy and cyclic voltammetry. The novel-modified sensor exhibited effective electrocatalytic activities toward anodic oxidation of nicotine. Calibration plot showed two linear regions with different sensitivity, 1.121 (r 2 = 0.982) in the range from 1 9 10 -6 to 9 9 10 -5 M and 0.164 (r 2 = 0.982) from 1 9 10 -4 M up to 1 9 10 -3 M. The detection limit was 1 lM. For six parallel detections of 1 mM nicotine, the relative standard deviation was 5.68 %, suggesting that the film-modified electrode had good reproducibility. Experimental parameters affecting the sensor response such as pH, modifier concentration and electrodeposition scan rate were found to be optimum at 7.0, 2 mg mL -1 and 80 mV s -1 , respectively.

Chitin and chitosan with unique properties and numerous applications can be produced from fungus. The production of chitin and chitosan from the mycelia of an Iranian Ganoderma lucidum was studied to improve cell growth and chitin productivity. Inoculum size and initial pH as two effective variables on the growth of G. lucidum and chitin production were optimized using response surface method (RSM) by central composite design (CCD). The results verified the significant effect of these two variables on the cell growth and chitin production. In optimum conditions, including pH = 5.7 and inoculum size of 7.4%, the cell dry weight was 5.91 g/L and the amount of chitin production was 1.08 g/L with the productivity of 0.083 g/(L day). The produced chitin and chitosan were characterized using XRD and FTIR. Moreover, the antibacterial activity of the produced chitosan was investigated and compared with the commercial chitosan. The results showed that the produced chitin and chitosan had suitable quality and the Iranian G. lucidum would be a great source for safe and high-quality chitin and chitosan production.

Background: One of the medicinal fungi that has been used in traditional medicine for a long time is the Basidiomycete fungus Fomes fomentarius, which is widely distributed in Iran. Polysaccharides as one of the metabolites of this fungus have anti-inflammatory, anti-diabetic, antibacterial, antioxidant, and anti-cancer properties. Materials & Methods: Optimization of independent variables of MgSO4.7H2O concentration, initial pH, yeast extract, and inoculum percentage to increase biomass and polysaccharide production of F. fomentarius was investigated using the Taguchi method. Then, the biological properties of the produced polysaccharide including antibacterial activity was investigated by bacterial colony counting method, antioxidant activity using DPPH free radical, and antiproliferative effect on 5 cancer cell lines MKN-45, AGS, A549, KYSE-30 and 5637 using MTS test. Results: The concentration of MgSO4.7H2O and initial pH had a significant effect (P<0.05) on the production of F. fomentarius polysaccharide and in optimal conditions polysaccharide production reaches 5.410 g/L. The polysaccharide of this fungus inhibits the growth of Staphylococcus aureus and Escherichia coli bacteria by 50% and 25%, respectively. The antioxidant activity of this polysaccharide in the DPPH test is 16.11%. The antiproliferative effect of this polysaccharide on cancer cells is different (KYSE-30> A549 ≥5637> AGS> MKN-45). This effect increases with increasing concentration. In KYSE-30 cell line treatment with 200 g/mL polysaccharide, cell viability reaches 40% after 72 hours. Conclusion: Optimizing the culture medium of the medicinal fungus Fomes fomentarius increases the production of polysaccharides up to 5.410 g/L. Optimization increases the biological activity of polysaccharides. Antibacterial activity against Staphylococcus aureus and Escherichia coli is 50% and 25%, respectively. The antioxidant activity of polysaccharides is 16.11% and the viability of KYSE-30 cancer cells reaches 40% after 72 hours.

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