SERS studies on the structure of thioglycolic acid monolayers on silver and gold

Królikowska, Agata; Kudelski, Andrzej; Michota, Agnieszka; Bukowska, J.

doi:10.1016/s0039-6028(03)00094-3

Cited by 183 publications

(112 citation statements)

References 11 publications

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“…40,41,42,43 A strong band at 670 cm -1 is characteristic of a C-S stretching vibration associated with the MUA trans conformer and a very weak feature also appears at 645 cm -1 attributed to the gauche conformation of the S-C-C chain.…”

Section: Resultsmentioning

confidence: 99%

Chemically bound gold nanoparticle arrays on silicon: assembly, properties and SERS study of protein interactions

Kamińska

Inya-Agha

Forster

et al. 2008

Phys. Chem. Chem. Phys.

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A highly reproducible and facile method for formation of ordered 2 dimensional arrays of CTAB protected 50 nm gold nanoparticles bonded to silicon wafers is described. The silicon wafers have been chemically modified with long-chain silanes terminated with thiol that penetrate the CTAB bilayer and chemically bind to the underlying gold nanoparticle. The silicon wafer provides a reproducibly smooth, chemically functionalizable and non-fluorescent substrate with a silicon phonon mode which may provide a convenient internal frequency and intensity calibration for vibrational spectroscopy. The CTAB bilayer provides a potentially biomimetic environment foranalyte, yet allows a sufficiently small nanoparticle separation to achieve a significant electric field enhancement. The arrays have been characterized using SEM and Raman spectroscopy. These studies reveal that the reproducibility of the arrays is excellent both between batches (< 10% RSD) and across a single batch (< 5% RSD). The arrays also exhibit good stability, and the effect of temperature on the arrays was also investigated. The interaction of protein and amino acid with the nanoparticle arrays was investigated using Raman microscopy to investigate their potential in bio-SERS spectroscopy. Raman of phenylalanine and the protein bovine pancreatic trypsin inhibitor, BPTI were studied using 785 nm excitation, coincident with the surface plasmon absorbance of the array. The arrays exhibit SERS enhancements of the order of 2.6 x 10 4 for phenylalanine, the standard deviation on the relative intensity of the 1555 cm -1 mode of phenylalanine is less than 10% for 100 randomly distributed locations across a single substrate and less than 20% between different substrates. Significantly, comparisons of the Raman spectra of the protein and phenlyalanine in solution and immobilized on the nanoparticle arrays indicates that the protein is non-randomly orientated on the arrays. Selective SERS enhancements suggest that aromatic residues penetrate through the bilayer inducing conformational changes in the protein.3

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Section: Resultsmentioning

confidence: 99%

Chemically bound gold nanoparticle arrays on silicon: assembly, properties and SERS study of protein interactions

Kamińska

Inya-Agha

Forster

et al. 2008

Phys. Chem. Chem. Phys.

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“…Nanoparticles have incredible importance due to their unusual optical (Krolikowska et al, 2003), chemical (Kumar et al, 2003), photoelectrochemical (Chandrasekharan & Kamat, 2000) and electronic (Peto et al, 2002) properties. The optoelectronic and physicochemical properties of nanoparticles are strongly dependent on particle size (Alivisatos, 1996).…”

Section: Introductionmentioning

confidence: 99%

Screening of different algae for green synthesis of gold nanoparticles

Parial

Patra

Dasgupta

et al. 2012

European Journal of Phycology

165

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The cyanobacteria Phormidium valderianum, P. tenue and Microcoleus chthonoplastes and the green algae Rhizoclonium fontinale, Ulva intestinalis, Chara zeylanica and Pithophora oedogoniana were exposed to hydrogen tetrachloroaurate solution and were screened for their suitability for producing nano-gold. All three cyanobacteria genera and two of the green algae (Rhizoclonium fontinale and Ulva intestinalis) produced gold nanoparticles intracellularly, confirmed by purple colouration of the thallus within 72 h of treatment at 20 C. Extracted nanoparticle solutions were examined by UV-vis spectroscopy, transmission electron microscopy (TEM) and X-ray diffractometry (XRD). XRD confirmed the reduction of Au (III) to Au (0). UV-vis spectroscopy and TEM studies indicated the production of nanoparticles having different shapes and sizes. Phormidium valderianum synthesized mostly spherical nanoparticles, along with hexagonal and triangular nanoparticles, at basic and neutral pHs (pH 9 and pH 7, respectively). Medicinally important gold nanorods were synthesized (together with gold nanospheres) only by P. valderianum at acidic pH (pH 5); this was initially determined by two surface plasmon bands in UV-vis spectroscopy and later confirmed by TEM. Spherical to somewhat irregular particles were produced by P. tenue and Ulva intestinalis (TEM studies). The UV-vis spectroscopy of the supernatant of other algal extracts indicated the formation of mostly spherical particles. Production of gold nanoparticles by algae is more ecofriendly than purely chemical synthesis. However, the choice of algae is important: Chara zeylanica and Pithophora oedogoniana were found to be unable to produce nanoparticles.

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“…Unicellular and multicellular organisms are known to produce inorganic materials either intra-or extra-cellular (Kumar et al, 2003;Peto et al, 2002;Sastry et al, 2004). There is an enormous interest in the synthesis of nanomaterials due to their unusual optical (Krolikowska et al, 2003), chemical (Kumar et al, 2003), electronic (Peto et al, 2002), biological (Glotzer andAnderson, 2010, Jones et al, 2010;Sako, 2006) properties.…”

Section: Introductionmentioning

confidence: 99%

Factors Affecting the Geometry of Silver Nanoparticles Synthesis in <i>Chrysosporium Tropicum</i> and <i>Fusarium Oxysporum</i>

Soni¹,

Prakash²

2011

American Journal of Nanotechnology

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Problem statement: Biosynthesis of nanoparticles using fungal cells is a novel approach to develop biotechnological possess such as bioleaching and bioremediation. In the present study, an effort was made to investigate the effect of physio-chemical parameters on the silver nanoparticle formation with the fungus Chrysosporium tropicum Carmichael and Fusarium oxysporum Schltdl. Approach: The possibilities to manipulating the geometry of silver nanoparticles by altering the key growth parameters such as pH, temperature, concentrations and time have been explored. The effect of AgNO 3 with the cell free extract of fungi and time, temperature, pH with the formation of silver has also been investigated. The presence of nanosilver has been carried out with the Micro-scan reader and has been confirmed by X-Rays Diffractometer (XRD). The micrographs of the silver nanoparticles have been evaluated through the Transmission Electron Microscope (TEM) and confirmed by Scanning Electron Microscope (SEM). The effect of concentrations with response to time, temperature and pH has studied with the help of Micro-scan reader and their microstructure analyzed by TEM and SEM. Results: It was observed that fungus C. tropicum and F. oxysporum Schltdl significantly activate the extra-cellular production of silver nanoparticles. The different sized and spherical shaped nanoparticles have been formed in different strains. With the increase in concentration, the absorbance increased with response to time (24-120h) and temperature. Significantly, the pH was found decreasing with the increase of absorbance. Conclusion: We presume that these changes initiate new geometry of nanosilver in the cell free solutions. These different shaped, sized and geometry of nanoparticles can be used in the field of medicine for drug formation and diseases diagnosis.

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SERS studies on the structure of thioglycolic acid monolayers on silver and gold

Cited by 183 publications

References 11 publications

Chemically bound gold nanoparticle arrays on silicon: assembly, properties and SERS study of protein interactions

Chemically bound gold nanoparticle arrays on silicon: assembly, properties and SERS study of protein interactions

Screening of different algae for green synthesis of gold nanoparticles

Factors Affecting the Geometry of Silver Nanoparticles Synthesis in <i>Chrysosporium Tropicum</i> and <i>Fusarium Oxysporum</i>

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