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Biosynthesis of gold nanoparticles assisted by the intracellular protein extract of Pycnoporus sanguineus and its catalysis in degradation of 4-nitroaniline.

Shi C, Zhu N, Cao Y, Wu P - Nanoscale Res Lett (2015)

Bottom Line: Fourier transform infrared (FTIR) analysis implied that the functional groups including hydroxyl, amine, and carboxyl were involved in the reduction of gold ions and stabilization of AuNPs.The catalysis results showed that 0.019 mg of AuNPs with average size of 6.07 nm could catalyze the complete degradation of 12.5 μmol of 4-nitroaniline within 6 min and the degradation rate increased drastically with the addition of AuNPs.All the results suggested that the IPE of P. sanguineus could be potentially applied for the eco-friendly synthesis of AuNPs.

View Article: PubMed Central - PubMed

Affiliation: School of Environment and Energy, South China University of Technology, Guangzhou, 510006 China.

ABSTRACT
The development of green procedure for the synthesis of gold nanoparticles (AuNPs) has gained great interest in the field of nanotechnology. Biological synthetic routes are considered to be environmentally benign and cost-effective. In the present study, the feasibility of AuNPs' synthesis via intracellular protein extract (IPE) of Pycnoporus sanguineus was explored. The characteristics of generated particles of formation, crystalline nature, and morphology and dimension were analyzed by UV-vis spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. UV-vis spectra exhibited strong absorption peaks in 520 to 560 nm, indicating the formation of AuNPs. XRD analysis revealed that the formed AuNPs were purely crystalline in nature. TEM observation showed that AuNPs with various shapes including spherical, pseudo-spherical, triangular, truncated triangular, pentagonal, and hexagonal, ranging from several to several hundred nanometers, were synthesized under different conditions. The average size of AuNPs decreased from 61.47 to 29.30 nm as the IPE addition increased from 10 to 80 mL. When the initial gold ion concentration changed from 0.5 to 2.0 mM, the average size rose from 25.88 to 51.99 nm. As in the case of solution pH, the average size was 84.29 nm with solution pH of 2.0, which diminished to 6.07 nm with solution pH of 12.0. Fourier transform infrared (FTIR) analysis implied that the functional groups including hydroxyl, amine, and carboxyl were involved in the reduction of gold ions and stabilization of AuNPs. The catalysis results showed that 0.019 mg of AuNPs with average size of 6.07 nm could catalyze the complete degradation of 12.5 μmol of 4-nitroaniline within 6 min and the degradation rate increased drastically with the addition of AuNPs. All the results suggested that the IPE of P. sanguineus could be potentially applied for the eco-friendly synthesis of AuNPs.

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Related in: MedlinePlus

UV-vis spectra during the degradation of 4-NA catalyzed by different volumes of AuNPs solution. (a) 1 mL. (b) 0.1 mL. (c) 0.01 mL.
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Fig5: UV-vis spectra during the degradation of 4-NA catalyzed by different volumes of AuNPs solution. (a) 1 mL. (b) 0.1 mL. (c) 0.01 mL.

Mentions: Upon adding 1 mL of AuNPs solution (average size of 6.07 nm, 0.19 mg/mL) to the mixture, the color faded from yellow to colorless within 3 min. The absorption peak at 380 nm disappeared, and another absorption peak at 302 nm occurred as well (Figure 5a), indicating the rapid catalytic reduction of 4-NA. In contrast, the blank control without the addition of AuNPs showed no change in color and absorption peak even after several days, thus implying the required role of AuNPs in this reduction process, which was in accordance with many previous reports [2,11]. The effect of catalyst addition on the degradation process was also evaluated by varying the volume of AuNPs solution while keeping the other parameters constant. As shown in Figure 5, the reduction rate increased with the increasing addition of AuNPs. The time needed to completely degrade 4-NA was 3, 6, and 40 min in the cases of 1, 0.1, and 0.01 mL of AuNPs solution, respectively. Taking the reduction efficiency and catalyst addition into consideration, 0.1 mL was preferred and about 0.019 mg AuNPs (dry weight) could catalyze the complete reduction of 12.5 μmol of 4-NA in 6 min. Since the concentration of NaBH4 much exceeded than that of 4-NA (100-fold), the kinetic reduction was considered to be pseudo-first order. The logarithm of the absorbance of 4-NA at 380 nm (lnA) will then decrease linearly with reaction time, and the calculated slope could be the rate constant (k) of the reaction. In this study, the k value was calculated to be 0.065 min−1.Figure 5


Biosynthesis of gold nanoparticles assisted by the intracellular protein extract of Pycnoporus sanguineus and its catalysis in degradation of 4-nitroaniline.

Shi C, Zhu N, Cao Y, Wu P - Nanoscale Res Lett (2015)

UV-vis spectra during the degradation of 4-NA catalyzed by different volumes of AuNPs solution. (a) 1 mL. (b) 0.1 mL. (c) 0.01 mL.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385306&req=5

Fig5: UV-vis spectra during the degradation of 4-NA catalyzed by different volumes of AuNPs solution. (a) 1 mL. (b) 0.1 mL. (c) 0.01 mL.
Mentions: Upon adding 1 mL of AuNPs solution (average size of 6.07 nm, 0.19 mg/mL) to the mixture, the color faded from yellow to colorless within 3 min. The absorption peak at 380 nm disappeared, and another absorption peak at 302 nm occurred as well (Figure 5a), indicating the rapid catalytic reduction of 4-NA. In contrast, the blank control without the addition of AuNPs showed no change in color and absorption peak even after several days, thus implying the required role of AuNPs in this reduction process, which was in accordance with many previous reports [2,11]. The effect of catalyst addition on the degradation process was also evaluated by varying the volume of AuNPs solution while keeping the other parameters constant. As shown in Figure 5, the reduction rate increased with the increasing addition of AuNPs. The time needed to completely degrade 4-NA was 3, 6, and 40 min in the cases of 1, 0.1, and 0.01 mL of AuNPs solution, respectively. Taking the reduction efficiency and catalyst addition into consideration, 0.1 mL was preferred and about 0.019 mg AuNPs (dry weight) could catalyze the complete reduction of 12.5 μmol of 4-NA in 6 min. Since the concentration of NaBH4 much exceeded than that of 4-NA (100-fold), the kinetic reduction was considered to be pseudo-first order. The logarithm of the absorbance of 4-NA at 380 nm (lnA) will then decrease linearly with reaction time, and the calculated slope could be the rate constant (k) of the reaction. In this study, the k value was calculated to be 0.065 min−1.Figure 5

Bottom Line: Fourier transform infrared (FTIR) analysis implied that the functional groups including hydroxyl, amine, and carboxyl were involved in the reduction of gold ions and stabilization of AuNPs.The catalysis results showed that 0.019 mg of AuNPs with average size of 6.07 nm could catalyze the complete degradation of 12.5 μmol of 4-nitroaniline within 6 min and the degradation rate increased drastically with the addition of AuNPs.All the results suggested that the IPE of P. sanguineus could be potentially applied for the eco-friendly synthesis of AuNPs.

View Article: PubMed Central - PubMed

Affiliation: School of Environment and Energy, South China University of Technology, Guangzhou, 510006 China.

ABSTRACT
The development of green procedure for the synthesis of gold nanoparticles (AuNPs) has gained great interest in the field of nanotechnology. Biological synthetic routes are considered to be environmentally benign and cost-effective. In the present study, the feasibility of AuNPs' synthesis via intracellular protein extract (IPE) of Pycnoporus sanguineus was explored. The characteristics of generated particles of formation, crystalline nature, and morphology and dimension were analyzed by UV-vis spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. UV-vis spectra exhibited strong absorption peaks in 520 to 560 nm, indicating the formation of AuNPs. XRD analysis revealed that the formed AuNPs were purely crystalline in nature. TEM observation showed that AuNPs with various shapes including spherical, pseudo-spherical, triangular, truncated triangular, pentagonal, and hexagonal, ranging from several to several hundred nanometers, were synthesized under different conditions. The average size of AuNPs decreased from 61.47 to 29.30 nm as the IPE addition increased from 10 to 80 mL. When the initial gold ion concentration changed from 0.5 to 2.0 mM, the average size rose from 25.88 to 51.99 nm. As in the case of solution pH, the average size was 84.29 nm with solution pH of 2.0, which diminished to 6.07 nm with solution pH of 12.0. Fourier transform infrared (FTIR) analysis implied that the functional groups including hydroxyl, amine, and carboxyl were involved in the reduction of gold ions and stabilization of AuNPs. The catalysis results showed that 0.019 mg of AuNPs with average size of 6.07 nm could catalyze the complete degradation of 12.5 μmol of 4-nitroaniline within 6 min and the degradation rate increased drastically with the addition of AuNPs. All the results suggested that the IPE of P. sanguineus could be potentially applied for the eco-friendly synthesis of AuNPs.

No MeSH data available.


Related in: MedlinePlus