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Peck K, Lien J, Su M, Stacy AD, Guo T. Bottom-Up Then Top-Down Synthesis of Gold Nanostructures Using Mesoporous Silica-Coated Gold Nanorods. ACS OMEGA 2023; 8:42667-42677. [PMID: 38024760 PMCID: PMC10652254 DOI: 10.1021/acsomega.3c05444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 09/22/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023]
Abstract
Gold nanostructures were synthesized by etching away gold from heat-treated mesoporous silica-coated gold nanorods (AuNR@mSiO2), providing an example of top-down modification of nanostructures made using bottom-up methodology. Twelve different types of nanostructures were made using this bottom-up-then-top-down synthesis (BUTTONS), of which the etching of the same starting nanomaterial of AuNR@mSiO2 was found to be controlled by how AuNR@mSiO2 were heat treated, the etchant concentration, and etching time. When the heat treatment occurred in smooth moving solutions in round-bottomed flasks, red-shifted longitudinal surface plasmon resonance (LSPR) was observed, on the order of 10-30 min, indicating increased aspect ratios of the gold nanostructures inside the mesoporous silica shells. When the heat treatment occurred in turbulent solutions in scintillation vials, a blue shift of the LSPR was obtained within a few minutes or less, resulting from reduced aspect ratios of the rods in the shells. The influence of the shape of the glassware, which may impact the flow patterns of the solution, on the heat treatment was investigated. One possible explanation is that the flow patterns affect the location of opened pores in the mesoporous shells, with the smooth flow of solution mainly removing CTAB surfactants from the pores along the cylindrical body of mSiO2, therefore increasing the aspect ratios after etching, and the turbulent solutions removing more surfactants from the pores of the two ends or tips of the silica shells, hence decreasing the aspect ratios after etching. These new stable gold nanostructures in silica shells, bare and without surfactant protection, may possess unique chemical properties and capabilities. Catalysis using heat-treated nanomaterials was studied as an example of potential applications of these nanostructures.
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Affiliation(s)
- Kristin
A. Peck
- Department of Chemistry, University
of California, Davis, California 95616, United States
| | - Jennifer Lien
- Department of Chemistry, University
of California, Davis, California 95616, United States
| | - Mengqi Su
- Department of Chemistry, University
of California, Davis, California 95616, United States
| | - Aaron D. Stacy
- Department of Chemistry, University
of California, Davis, California 95616, United States
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2
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Ghamsari M, Orouji A, Hormozi-Nezhad MR. Fast and Facile Etching of Gold Nanorods by N-Halosuccinimides: Toward Multicolorimetric Identification and Quantification of 20 Natural Amino Acids. Anal Chem 2023; 95:15985-15993. [PMID: 37791823 DOI: 10.1021/acs.analchem.3c03106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Gold nanorods (AuNRs) have recently become fascinating chromophores in the field of colorimetric sensing because of their eye-catching rainbow colors along with the high dimensionality of their optical profile. The etching of AuNRs using an analyte-sensitive oxidizing agent is particularly an attractive tool not only for adjusting their plasmonic behavior through altering their aspect ratio but also for correlating the observed signal with the identity and concentration of the analyte. However, the deployment of this strategy in the field of sensing has been seriously hindered by various factors ranging from slow etching kinetics and the need for nonambient temperatures to low degrees of controllability along with the high toxicity of the etchants. To resolve these challenges, the present study aims to introduce the outstanding potentials of two inexpensive mild oxidants comprising N-bromosuccinimide (NBS) and N-chlorosuccinimide (NCS) in the highly fast and controllable etching of AuNRs at room temperature. By controlling the concentration of the etchant and the pH of the medium, the longitudinal and transversal peaks could be well adjusted with nanometer precision. In an attempt to elucidate the etching mechanism, the effects of various parameters including the etchant concentration and pH, as well as the kinetics of the etching process were thoroughly investigated. After all, the capability of NBS in decarboxylating the amino acids was further exploited in the design of an all-inclusive multicolorimetric sensor array based on the etching of AuNRs for the sensitive quantification and highly accurate discrimination of all 20 amino acids in the micromolar range. To this end, the acquired data set was analyzed by two machine learning techniques including partial least-squares regression (PLSR) and linear discriminant analysis (LDA). The versatility of N-halosuccinimide reactions with various categories of organic compounds underlies ample opportunities for the design of diverse multicolorimetric sensors, further glamorizing the prospect of this approach.
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Affiliation(s)
- Mahdi Ghamsari
- Department of Chemistry, Sharif University of Technology, Tehran, 11155-9516, Iran
| | - Afsaneh Orouji
- Department of Chemistry, Sharif University of Technology, Tehran, 11155-9516, Iran
| | - Mohammad Reza Hormozi-Nezhad
- Department of Chemistry, Sharif University of Technology, Tehran, 11155-9516, Iran
- Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, 11155-9516, Iran
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3
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Al-Zubeidi A, Wang Y, Lin J, Flatebo C, Landes CF, Ren H, Link S. d-Band Holes React at the Tips of Gold Nanorods. J Phys Chem Lett 2023:5297-5304. [PMID: 37267074 DOI: 10.1021/acs.jpclett.3c00997] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Reactive hot spots on plasmonic nanoparticles have attracted attention for photocatalysis as they allow for efficient catalyst design. While sharp tips have been identified as optimal features for field enhancement and hot electron generation, the locations of catalytically promising d-band holes are less clear. Here we exploit d-band hole-enhanced dissolution of gold nanorods as a model reaction to locate reactive hot spots produced from direct interband transitions, while the role of the plasmon is to follow the reaction optically in real time. Using a combination of single-particle electrochemistry and single-particle spectroscopy, we determine that d-band holes increase the rate of gold nanorod electrodissolution at their tips. While nanorods dissolve isotropically in the dark, the same nanoparticles switch to tip-enhanced dissolution upon illimitation with 488 nm light. Electron microscopy confirms that dissolution enhancement is exclusively at the tips of the nanorods, consistent with previous theoretical work that predicts the location of d-band holes. We, therefore, conclude that d-band holes drive reactions selectively at the nanorod tips.
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Affiliation(s)
- Alexander Al-Zubeidi
- Department of Chemistry, Rice University, 6100 Main Street, Houston, TX 77005, United States
| | - Yufei Wang
- Department of Chemistry, The University of Texas at Austin, 105 East 24th Street, Austin, TX 78712, United States
| | - Jiamu Lin
- Department of Chemistry, Rice University, 6100 Main Street, Houston, TX 77005, United States
| | - Charlotte Flatebo
- Applied Physics Program, Rice University, 6100 Main Street, Houston, TX 77005, United States
| | - Christy F Landes
- Department of Chemistry, Rice University, 6100 Main Street, Houston, TX 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, TX 77005, United States
| | - Hang Ren
- Department of Chemistry, The University of Texas at Austin, 105 East 24th Street, Austin, TX 78712, United States
| | - Stephan Link
- Department of Chemistry, Rice University, 6100 Main Street, Houston, TX 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, United States
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4
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Ghosh P, Thambi V, Kar A, Chakraborty AL, Khatua S. Light-induced in situ active tuning of the LSPR of gold nanorods over 90 nm. OPTICS LETTERS 2021; 46:4562-4565. [PMID: 34525047 DOI: 10.1364/ol.435242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate an easy and controllable method for light-induced active tuning of the longitudinal surface plasmon resonance (LSPR) of gold nanorods (AuNRs) over ∼94nm. The red-shift of the LSPR can be controlled by varying the time of exposure to a 532 nm laser. The tuning is achieved by photo-induced dissolution of individual AuNRs by sodium dodecyl sulfate (SDS) under continuous illumination. The dissolution of the AuNRs increases the aspect ratio, and consequently the LSPR exhibits a gradual but large redshift. A key feature is that it is possible to selectively tune the LSPR of a specific AuNR in a group while leaving the others totally unaffected. Such controllable, light-induced, post-synthesis fine-tuning of the LSPR is useful for tailoring the plasmonic response of individual AuNRs for a wide range of applications.
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5
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Al-Zubeidi A, Stein F, Flatebo C, Rehbock C, Hosseini Jebeli SA, Landes CF, Barcikowski S, Link S. Single-Particle Hyperspectral Imaging Reveals Kinetics of Silver Ion Leaching from Alloy Nanoparticles. ACS NANO 2021; 15:8363-8375. [PMID: 33886276 DOI: 10.1021/acsnano.0c10150] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Gold-silver alloy nanoparticles are interesting for multiple applications, including heterogeneous catalysis, optical sensing, and antimicrobial properties. The inert element gold acts as a stabilizer for silver to prevent particle corrosion, or conversely, to control the release kinetics of antimicrobial silver ions for long-term efficiency at minimum cytotoxicity. However, little is known about the kinetics of silver ion leaching from bimetallic nanoparticles and how it is correlated with silver content, especially not on a single-particle level. To characterize the kinetics of silver ion release from gold-silver alloy nanoparticles, we employed a combination of electron microscopy and single-particle hyperspectral imaging with an acquisition speed fast enough to capture the irreversible silver ion leaching. Single-particle leaching profiles revealed a reduction in silver ion leaching rate due to the alloying with gold as well as two leaching stages, with a large heterogeneity in rate constants. We modeled the initial leaching stage as a shrinking-particle with a rate constant that exponentially depends on the silver content. The second, slower leaching stage is controlled by the electrochemical oxidation potential of the alloy being steadily increased by the change in relative gold content and diffusion of silver atoms through the lattice. Interestingly, individual nanoparticles with similar sizes and compositions exhibited completely different silver ion leaching yields. Most nanoparticles released silver completely, but 25% of them appeared to arrest leaching. Additionally, nanoparticles became slightly porous. Alloy nanoparticles, produced by scalable laser ablation in liquid, together with kinetic studies of silver ion leaching, provide an approach to design the durability or bioactivity of alloy nanoparticles.
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Affiliation(s)
- Alexander Al-Zubeidi
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Frederic Stein
- Technical Chemistry I and Center for Nanointegration, Duisburg-Essen, University of Duisburg-Essen, Universitätsstraße 7, 45141 Essen, Germany
| | - Charlotte Flatebo
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Applied Physics Program, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Christoph Rehbock
- Technical Chemistry I and Center for Nanointegration, Duisburg-Essen, University of Duisburg-Essen, Universitätsstraße 7, 45141 Essen, Germany
| | - Seyyed Ali Hosseini Jebeli
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Christy F Landes
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Stephan Barcikowski
- Technical Chemistry I and Center for Nanointegration, Duisburg-Essen, University of Duisburg-Essen, Universitätsstraße 7, 45141 Essen, Germany
| | - Stephan Link
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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6
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Wang S, Lin Q, Xu W, An Q, Zhou R, Yu CJ, Xu D, Yuan Z. Precisely tuning the longitudinal localized surface plasmon resonance of gold nanorods via additive-regulated overgrowth. RSC Adv 2020; 10:12619-12625. [PMID: 35497578 PMCID: PMC9051167 DOI: 10.1039/d0ra00579g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 03/06/2020] [Indexed: 01/02/2023] Open
Abstract
An additive-regulated overgrowth strategy for preparing gold nanorods with precise longitudinal localized surface plasmon resonance is proposed.
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Affiliation(s)
- Suyan Wang
- National Engineering Laboratory for Rice and By-products Further Processing
- Central South University of Forestry &Technology
- Changsha 410004
- China
| | - Qinlu Lin
- National Engineering Laboratory for Rice and By-products Further Processing
- Central South University of Forestry &Technology
- Changsha 410004
- China
| | - Weizhen Xu
- National Engineering Laboratory for Rice and By-products Further Processing
- Central South University of Forestry &Technology
- Changsha 410004
- China
| | - Qingxiao An
- National Engineering Laboratory for Rice and By-products Further Processing
- Central South University of Forestry &Technology
- Changsha 410004
- China
| | - Rongju Zhou
- National Engineering Laboratory for Rice and By-products Further Processing
- Central South University of Forestry &Technology
- Changsha 410004
- China
| | - Cheng-Ju Yu
- Department of Applied Physics and Chemistry
- University of Taipei
- Taipei 10048
- Republic of China
| | - Dong Xu
- National Engineering Laboratory for Rice and By-products Further Processing
- Central South University of Forestry &Technology
- Changsha 410004
- China
| | - Zhiqin Yuan
- State Key Laboratory of Chemical Resource Engineering
- College of Chemistry
- Beijing University of Chemical Technology
- Beijing 100029
- China
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7
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Hogan LT, Horak EH, Ward JM, Knapper KA, Nic Chormaic S, Goldsmith RH. Toward Real-Time Monitoring and Control of Single Nanoparticle Properties with a Microbubble Resonator Spectrometer. ACS NANO 2019; 13:12743-12757. [PMID: 31614083 PMCID: PMC6887843 DOI: 10.1021/acsnano.9b04702] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 10/15/2019] [Indexed: 05/22/2023]
Abstract
Optical microresonators have widespread application at the frontiers of nanophotonic technology, driven by their ability to confine light to the nanoscale and enhance light-matter interactions. Microresonators form the heart of a recently developed method for single-particle photothermal absorption spectroscopy, whereby the microresonators act as microscale thermometers to detect the heat dissipated by optically pumped, nonluminescent nanoscopic targets. However, translation of this technology to chemically dynamic systems requires a platform that is mechanically stable, solution compatible, and visibly transparent. We report microbubble absorption spectrometers as a versatile platform that meets these requirements. Microbubbles integrate a two-port microfluidic device within a whispering gallery mode microresonator, allowing for the facile exchange of chemical reagents within the resonator's interior while maintaining a solution-free environment on its exterior. We first leverage these qualities to investigate the photoactivated etching of single gold nanorods by ferric chloride, providing a method for rapid acquisition of spatial and morphological information about nanoparticles as they undergo chemical reactions. We then demonstrate the ability to control nanorod orientation within a microbubble through optically exerted torque, a promising route toward the construction of hybrid photonic-plasmonic systems. Critically, the reported platform advances microresonator spectrometer technology by permitting room-temperature, aqueous experimental conditions, which may be used for time-resolved single-particle experiments on non-emissive, nanoscale analytes engaged in catalytically and biologically relevant chemical dynamics.
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Affiliation(s)
- Levi T. Hogan
- Department
of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Erik H. Horak
- Department
of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Jonathan M. Ward
- Light-Matter
Interactions for Quantum Technologies Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Kassandra A. Knapper
- Department
of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Síle Nic Chormaic
- Light-Matter
Interactions for Quantum Technologies Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Randall H. Goldsmith
- Department
of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- E-mail:
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8
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Yoon S, Kim C, Lee B, Lee JH. From a precursor to an etchant: spontaneous inversion of the role of Au(iii) chloride for one-pot synthesis of smooth and spherical gold nanoparticles. NANOSCALE ADVANCES 2019; 1:2157-2161. [PMID: 36131976 PMCID: PMC9417709 DOI: 10.1039/c9na00157c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 04/14/2019] [Indexed: 05/14/2023]
Abstract
We report the inversion of the role of Au(iii) chloride, from a gold precursor to an etchant, for the synthesis of smooth and spherical AuNPs with nanoscale size tunability in a one-pot-system. Inversion of the role of Au(iii) chloride was achieved by regulating the ratio between the reducing agent and Au(iii) chloride.
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Affiliation(s)
- Seokyoung Yoon
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea +82-502-302-1918 +82-31-290-7404
| | - Chansong Kim
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea
| | - Byoungsang Lee
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea
| | - Jung Heon Lee
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea +82-502-302-1918 +82-31-290-7404
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea
- Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea
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9
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Khanal BP, Zubarev ER. Chemical Transformation of Nanorods to Nanowires: Reversible Growth and Dissolution of Anisotropic Gold Nanostructures. ACS NANO 2019; 13:2370-2378. [PMID: 30753055 DOI: 10.1021/acsnano.8b09203] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This manuscript describes a reversible wet chemical process for the tip-selective one-dimensional (1D) growth and dissolution of gold nanorods (AuNRs) and gold nanowires (AuNWs). Tip-selective dissolution was achieved by oxidation of AuNRs with a Au(III)/CTAB complex, whereas the growth of AuNRs was carried out by the reduction of Au(I) ions on the AuNR surface with a mild reducing agent, ascorbic acid (AA). Both the dissolution and growth processes are highly tip selective and proceed exclusively in one dimension. A decrease in the aspect ratio (AR) of AuNRs during the dissolution resulted in a blue shift in the longitudinal plasmon band (LPB) position, and red shifts in the LPB position were achieved by increasing the AR by 1D growth of AuNRs. Both growth and dissolution processes are fully controllable and can be stopped and resumed at any given time when the desired AR and/or LPB position is achieved. In addition, the tip-selective 1D growth of AuNRs can be continued with the additional supply of Au(I)/CTAB/AA solution to produce extremely long AuNWs.
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Affiliation(s)
- Bishnu P Khanal
- Department of Chemistry , Rice University , 6100 Main Street , Houston , Texas 77005 , United States
| | - Eugene R Zubarev
- Department of Chemistry , Rice University , 6100 Main Street , Houston , Texas 77005 , United States
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10
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Carattino A, Caldarola M, Orrit M. Gold Nanoparticles as Absolute Nanothermometers. NANO LETTERS 2018; 18:874-880. [PMID: 29272135 PMCID: PMC5817619 DOI: 10.1021/acs.nanolett.7b04145] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/21/2017] [Indexed: 05/19/2023]
Abstract
Nanothermometry is a challenging field that can open the door to intriguing questions ranging from biology and medicine to material sciences. Gold nanorods are excellent candidates to act as nanoprobes because they are reasonably bright emitters upon excitation with a monochromatic source. Gold nanoparticles are commonly used in photothermal therapy as efficient transducers of electromagnetic radiation into heat. In this work we use the spectrum of the anti-Stokes emission from gold nanorods irradiated in resonance to measure the absolute temperature of the nanoparticles and their surrounding medium without the need for a previous calibration. We show a 4 K accuracy in the determination of the temperature of the medium with spectral measurements of 180 s integration time. This procedure can be easily implemented in any microscope capable of acquiring emission spectra, and it is not limited to any specific shape of nanoparticles.
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Schürmann R, Bald I. Effect of adsorption kinetics on dissociation of DNA-nucleobases on gold nanoparticles under pulsed laser illumination. Phys Chem Chem Phys 2018; 19:10796-10803. [PMID: 28244511 DOI: 10.1039/c6cp08433h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Photothermal therapy is a novel approach to destroy cancer cells by an increase of temperature due to laser illumination of gold nanoparticles (GNPs) that are incorporated into the cells. Here, we study the decomposition of DNA nucleobases via irradiation of gold nanoparticles with ns-laser pulses. The kinetics of the adsorption and decomposition process is described by a theoretical model based on the Langmuir assumptions and correlated with experimentally determined reaction rates revealing a strong influence of the nucleobase specific adsorption. Beside the four nucleobases, their brominated analogs, which are potential radiosensitizers in cancer therapy, are also investigated and show a significant modification of the decomposition rates. The fastest decomposition rates are observed for adenine, 8-bromoadenine, 8-bromoguanine and 5-bromocytosine. These results are in good agreement with the relative adsorption rates that are determined from the aggregation kinetics of the GNPs taking the effect of an inhomogeneous surface into account. For adenine and its brominated analog, the decomposition products are further analyzed by surface enhanced Raman scattering (SERS) indicating a strong fragmentation of the molecules into their smallest subunits.
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Affiliation(s)
- Robin Schürmann
- Institute of Chemistry - Physical Chemistry, University of Potsdam, Potsdam, Germany.
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12
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Mesquite Gum as a Novel Reducing and Stabilizing Agent for Modified Tollens Synthesis of Highly Concentrated Ag Nanoparticles. MATERIALS 2016; 9:ma9100817. [PMID: 28773938 PMCID: PMC5456612 DOI: 10.3390/ma9100817] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 09/26/2016] [Indexed: 01/05/2023]
Abstract
The synthesis that is described in this study is for the preparation of silver nanoparticles of sizes ranging from 10 nm to 30 nm with a defined shape (globular), confirmed by UV-vis, SEM, STEM and DLS analysis. This simple and favorable one-step modified Tollens reaction does not require any special equipment or other stabilizing or reducing agent except for a solution of purified mesquite gum, and it produces aqueous colloidal dispersions of silver nanoparticles with a stability thatexceeds three months, a relatively narrow size distribution, a low tendency to aggregate and a yield of at least 95% for all cases. Reaction times are between 15 min and 60 min to obtain silver nanoparticles in concentrations ranging from 0.1 g to 3 g of Ag per 100 g of reaction mixture. The proposed synthetic method presents a high potential for scale-up, since its production capacity is rather high and the methodology is simple.The synthesis that is described in this study is for the preparation of silver nanoparticles of sizes ranging from 10 nm to 30 nm with a defined shape (globular), confirmed by UV-vis, SEM, STEM and DLS analysis. This simple and favorable one-step modified Tollens reaction does not require any special equipment or other stabilizing or reducing agent except for a solution of purified mesquite gum, and it produces aqueous colloidal dispersions of silver nanoparticles with a stability thatexceeds three months, a relatively narrow size distribution, a low tendency to aggregate and a yield of at least 95% for all cases. Reaction times are between 15 min and 60 min to obtain silver nanoparticles in concentrations ranging from 0.1 g to 3 g of Ag per 100 g of reaction mixture. The proposed synthetic method presents a high potential for scale-up, since its production capacity is rather high and the methodology is simple.
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