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Raman Spectroscopy Analysis of the Morphology of Gold Nanoparticles Produced by Laser Ablation in Aqueous Proteinogenic Amino Acid for the Detection of Mercury in Water

Carbajal-Morán Hipólito

Journal of Ecological Engineering

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2023

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Vol. 24, nr 11

169--175

EN

The objective of the research was to analyze by Raman spectroscopy the morphology of gold nanoparticles generated by laser ablation in L-Cysteine of purity ≥ 97% dissolved in ultrapure water for the detection by color change of mercury dissolved in water. Three samples of 10 ml of ultrapure water were prepared with aggregation of 10 ul of L-Cysteine with concentrations of 1, 10 and 20 mM; the generation of the gold nanoparticles was by laser ablation with a wavelength λ = 1064 nm, energy of 60.28 mJ/p located at 30 cm from the convex lens generating ablation at 10 cm on a gold plate of dimensions 10×15 mm with thickness of 1 mm, for 30 min. The gold nanoparticles generated in these aqueous environments were characterized by Raman spectroscopy using a laser with a sensitivity of 785 nm with Raman Shift analysis range 860–3200 cm-1 and controlled power at 499 mW. The nanoparticles presented maximum peak resonance around Raman Shift 1164.96 cm-1 and 1288.06 cm-1. With the AuNPs + L-Cysteine sample with concentration of 10 mM, the author proceeded to the detection of Hg2+ prepared in 20 μl of ultrapure water at concentrations of 0.1, 5 and 10 μM; when adding 100 μl of AuNPs + L-Cysteine two peak absorbance spectra were obtained with different amplitudes observed by UV–Vis spectroscopy, indicating that Hg2+ decreased the repulsion of the negatively charged AuNPs, generating the visible color change for the three concentrations of Hg2+ with 25 minutes of agitation, turning intense purple for 10 μM of Hg2+; enabling the detection of mercury in water.

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Influence of Gold Nanoparticles on the Photocatalytic Action of Titanium Dioxide in Physical-Chemical Parameters of Greywater

Carbajal-Morán Hipólito, Márquez-Camarena Javier F., Galván-Maldonado Carlos A.

Journal of Ecological Engineering

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2022

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Vol. 23, nr 1

182--192

EN

The objective of the work was to evaluate the influence of gold nanoparticles, obtained by laser ablation, on the photocatalytic action of titanium dioxide in the improvement of the physical-chemical parameters of domestic greywater, with visualization by means of a PLC. The YAG laser equipment was used for the production of spherical gold nanoparticles, whereas the Raman spectroscope allowed characterizing the different particles contained in aqueous solutions. The solar photoreactor programmable and viewable from PLC with connection to sensors allowed determining the variations of the pH, EC, DO and FCL parameters. The work consisted of a control group (greywater + titanium dioxide) and an experimental group (greywater + titanium dioxide + gold nanoparticles). The titanium dioxide doses for both groups were 0.5 mg/L and the gold nanoparticles were 0.20 ml per liter of greywater only for the control group. The experiments were carried out on sunny days with the exposure periods of 30 and 60 minutes around solar noon with an average UV index of 13.35. Once the experiments were carried out, it was determined that the pH improved by 5.30%, EC by 3.03%, DO by 29.3% and FCL by 43.71%, so that the gold nanoparticles dissolved in the aqueous solution of titanium dioxide with greywater positively influenced the improvement of the photocatalytic action of titanium dioxide in the physical-chemical parameters of greywater.

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Chemical surface growth and physical properties of the Au nanoparticles array on glass slides

Kusnezh V. V., Il'Chuk H. A., Tsyupko F. I., Placzek-Popko E., Gwozdz K., Bieganski P.

Materials Science Poland

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2018

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Vol. 36, No. 1

42--45

EN

Gold nanoparticle array on pretreated glass substrates was fabricated by chemical surface growth from the AuCl3, CH2O and Na2CO3 components in aqueous solutions mixture. Transmission, absorption and reflectivity spectra were measured with an UV-Vis spectrophotometer. A change in plasmon maximum absorption position depending on the growth conditions was investigated. The surface morphology was studied by atomic force microscopy. The statistical analysis of the heights, particles diameter and image cross-sections was carried out by scanning probe microscopy methods and the Au NPs size dependence on the growth time was experimentally determined. The results of this paper will contribute to the optimization of plasmonic CdS/CdTe solar cell.

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Fluorescent DNA probe based on CdTe/CdS/SiO2 core/multishell composite nanoparticles

Song J., Dai Z., Guo W., Li Y., Wang W.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

48--50

EN

A novel kind of fluorescent DNA Probe based on fluorescence resonance energy transfer (FRET) was presented in this paper when CdTe/CdS/SiO2 core/multishell fluorescent nanoparticles were as energy donors and Au nanoparticles (AuNPs) were as energy acceptors. The DNA probes were prepared when energy donors and acceptors were conjugated with two single-stranded complementary oligonucleotides respectively and hybridized with each other. Compared with the fluorescent intensity of single-stranded DNA (ssDNA) conjugated CdTe/CdS/SiO2 nanoparticles (CdTe/CdS/SiO2-DNA), the fluorescent intensity of DNA probe was significantly increased and the FRET efficiency was about 71%. The detection results indicated that this novel DNA probe had excellent detection and specificity of completely complementary target ssDNA.

PL

W pracy zaprezentowano nowy rodzaj fluoryzującej próbki DNA opartej o rezonansowe przenoszenie energii fluoryzacji (FRET), gdzie donorami energii są nanocząstki CdTe/CdS/SiO2 z jądrową fluorescencją powłokową a akceptorami energii nanocząstki Au (AuNPs). W przygotowanych próbkach DNA energia donora i akceptora są odpowiednio sprzężone z dwoma pojedynczo skręconymi komplementarnymi oligonukleotydami i hybrydyzowane ze sobą. Intensywność fluorescencji próbki DNA ze sprzężonymi nanocząstkami CdTe/CdS/SiO2 (CdTe/CdS/SiO2 -DNA) w porównaniu z próbką pojedynczo-skręconego DNA (ssDNA) znacząco wzrasta, Wydajność FRET wynosi około 71%. Wyniki wykrywalności wykazują, że nowa próbka DNA ma doskonałą wykrywalność i swoistość do całkowicie komplementarnego docelowego ssDNA.