scholarly journals Antifungal Activity of TiO2/Ag Nanoparticles under Visible Light Irradiation

2020 ◽  
Vol 21 (1) ◽  
pp. 14
Author(s):  
Nahzim Rahmat ◽  
Endang Tri Wahyuni ◽  
Adhitasari Suratman

The doping of TiO2 by Ag(I) from [Ag(S2O3)2]3– contained in radiophotography wastewater by photoreduction method has been performed. TiO2/AgNPs photocatalyst was examined for its activity as an antifungal material for the inhibition of C. albicans in water under visible light irradiation. In the doping process, the weight of TiO2 was varied to obtain TiO2/AgNPs with different amounts of Ag. The TiO2/AgNPs samples were characterized by using FTIR, SRUV, TEM, SEM-EDX, and XRD methods. The antifungal test was carried out by disc diffusion method under visible light irradiation, wherein the amount of Ag-doped on TiO2, the dose of TiO2/AgNPs, and the irradiation time were optimized. The research results indicated that the antifungal activity of TiO2/AgNPs in inhibiting C. albicans has been successfully prepared. The highest inhibition was achieved by using 0.5 g/L of TiO2/AgNPs (I), at 5 h of irradiation time.

10.5219/1695 ◽  
2021 ◽  
Vol 15 ◽  
pp. 1112-1119
Author(s):  
Hana Ďúranová ◽  
Veronika Valková ◽  
Lucia Galovičová ◽  
Jana Štefániková ◽  
Miroslava Kačániová

Fungal food spoilage plays a key role in the deterioration of food products, and finding a suitable natural preservative can solve this problem. Therefore, antifungal activity of green mandarin (Citrus reticulata) essential oil (GMEO) in the vapor phase against the growth of Penicillium (P.) expansum and P. chrysogenum inoculated on wheat bread (in situ experiment) was investigated in the current research. The volatile compounds of the GMEO were analyzed by a gas chromatograph coupled to a mass spectrometer (GC–MS), and its antioxidant activity was determined by testing free radical-scavenging capacity (DPPH assay). Moreover, the disc diffusion method was used to analyze the antifungal activity of GMEO in in vitro conditions. The results demonstrate that the Citrus reticulata EO consisted of α-limonene as the most abundant component (71.5%), followed by γ-terpinene (13.9%), and β-pinene (3.5%), and it displayed the weak antioxidant activity with the value of inhibition 5.6 ±0.7%, which corresponds to 103.0 ±6.4 µg TEAC.mL-1. The findings from the GMEO antifungal activity determination revealed that values for the inhibition zone with disc diffusion method ranged from 0.00 ±0.00 (no antifungal effectiveness) to 5.67 ±0.58 mm (moderate antifungal activity). Finally, exposure of Penicillium strains growing on bread to GMEO in vapor phase led to the finding that 250 μL.L-1 of GMEO exhibited the lowest value for mycelial growth inhibition (MGI) of P. expansum (-51.37 ±3.01%) whose negative value reflects even supportive effect of the EO on the microscopic fungus growth. On the other hand, GMEO at this concentration (250 μL.L-1) resulted in the strongest inhibitory action (MGI: 54.15 ±1.15%) against growth of P. chrysogenum. Based on the findings it can be concluded that GMEO in the vapor phase is not an effective antifungal agent against the growth of P. expansum inoculated on bread; however, its antifungal potential manifested against P. chrysogenum suggests GMEO to be an appropriate alternative to the use of chemical inhibitors for bread preservation.


Author(s):  
Ameneh Takesh ◽  
Mahnaz Fatahinia ◽  
Ali Zarei Mahmoudabadi

Background and Aims: The study aimed to determine the effectiveness of three medicinal plant extracts on fungi with three methods and to compare methods.  Material and methods: This study examined the antifungal properties of cumin (Cuminum cyminum L), ginger (Zingiber officinale Roscoe) and Nafe Venus (Umbilicus intermedius boiss) extracts against fungi including, Aspergillus spp., Penicillium spp., Mucor spp., Stemphylium spp., Drechslera spp., Alternaria spp., Cladosporium spp., and Aureobasidium pullulans. Furthermore, 17 candida isolates including, C. albicans, C. glabrata and C. dubliniensis were tested. In the present study two methods of disc diffusion method, agar wells diffusion method were used for assay. Then, the mixing with culture medium method was used for assessment of the antifungal activity of extracts against Alternaria sp.(as black mold), A. terreus (as hyaline mold) and C. albicans (as yeast) to compare methods as well. Results: No fungi were susceptible to extracts in disc diffusion method and agar wells diffusion method. But, this study showed that in mixing with culture medium method, cumin extract has valuable anti-fungal property and Umbilicus intermedius boiss has the inhibitory properties against the black fungi. Furthermore, it is found that mixing with culture medium method is more efficient than disc and agar well diffusion methods. Alternaria sp. and C. albicans were susceptible and resistant to all extracts.  Conclusions: it is found that mixing with culture medium method is more efficient than disc and agar well diffusion methods and inhibitory potency of the extracts varies according to the type of extraction and their concentration.


2021 ◽  
Vol 9 (06) ◽  
pp. 420-427
Author(s):  
R. Neelima ◽  
◽  
B. Sujatha ◽  
N.V. Ramana ◽  
B.V. Rao ◽  
...  

In vitro evaluation of antifungal activity by disc diffusion method was carried out on leaf extracts of D.falcata, D. falcata var pubescens, V. monoicum and V. orientale and stem extracts of D. falcata, D. falcata var pubescens, V. articulatum and V.orientale using three different solvents viz., methanol, n-hexane and ethyl acetate. The antifungal activity was tested on three fungal strains include Fusarium oxysporum, Phytophthora infestans, Sclerotium rolfsii. Overall leaf extracts exerted better inhibitory activity than stem counterparts. Among all, only V. orientale was effective against the three fungal species.Compared to stem extracts, leaf extracts of D. falcata var pubescens have shown higher antifungal activity.


2012 ◽  
Vol 578 ◽  
pp. 69-72
Author(s):  
Zhuo Zhao

InVO4 films were supported on glass springs via a sol-gel method. Ultrafine Ag nanoparticles, with a particle size of 5~10nm, were deposited on the surface of InVO4 films by a photoreduction process. XRD results revealed that high temperature phase of InVO4 (orthorhombic phase) could be obtained at a relatively low temperature (<500°C). The surface of InVO4 films was rough with numerous small grooves and edges. The visible light induced photocatalytic activity of InVO4 films increased by deposition of Ag nanoparticles. Under visible light irradiation, the excited electrons in conduction band of InVO4 could be trapped by small Ag particles, thus limiting the recombination of photogenerated electron-hole pairs.


2022 ◽  
Author(s):  
G. Roshini ◽  
V. Sathish ◽  
S. Manigandan ◽  
A. Tamilarasi ◽  
E. Priyanka

Abstract In this paper, the highly stable Ag/CdS-WO2 nanocomposite was fabricated by a facile and capping agent-free hydrothermal technique. The fabricated Ag doped CdS-WO2 nanocomposite were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and UV-vis diffuse reflectance (DRS) spectroscopy. The photocatalytic performance of synthesized photocatalysts was evaluated for the photodegradation of rhodamine B (Rh B) under visible light irradiation (VLI). The parameters used for the optimization of the photocatalyst were pH, catalyst dose, oxidant dose, and irradiation time. Based on this, a possible reaction mechanism for the enhancement of photocatalytic activity of Ag/CdS-WO2 has been proposed. Hence, we have a tendency to believe it might be a promising material that may be used for the photodegradation of organic pollutants present in wastewater.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fu Su ◽  
Pengpeng Li ◽  
Jianshu Huang ◽  
Meijuan Gu ◽  
Zhiying Liu ◽  
...  

AbstractIn this work, CeO2 nanosheets decorated with Ag2O and AgBr are successfully fabricated via a simple sediment-precipitation method. The as-prepared ternary Ag2O/AgBr–CeO2 composite with double Z-scheme construction was analyzed by various analytical techniques. Ag nanoparticles (NPs) used as the electron medium could reduce the recombination of photoelectrons and holes, thus leading to the improvement of photocatalytic performance of these catalysts. Due to the unique structure and composite advantages, the optimal Ag2O/AgBr–CeO2 photocatalysts exhibit the superior tetracycline (TC) degradation efficiency of 93.23% and favorable stability with near-initial capacity under visible light irradiation. This ternary Z-scheme structure materials will be the well-promising photocatalysts or the purification of antibiotic wastewater.


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