Nanoarchitectonics of photothermal materials to enhance the sensitivity of lateral flow assays

• Elangovan Sarathkumar,
• Rajasekharan S. Anjana and
• Ramapurath S. Jayasree

Beilstein J. Nanotechnol. 2023, 14, 988–1003, doi:10.3762/bjnano.14.82

• LSPR effect highly depends on size, shape, composition, interparticle distance, dielectric constant, and surrounding medium of the particles [36][37]. While Pt, Ag, and Au particles all exhibit photothermal properties, Au nanoparticles are commonly used for photothermal applications. By changing the

• under the terms of the Creative Commons Attribution 4.0 International License, https://creativecommons.org/licenses/by/4.0)). Photothermal conversion efficiency of Au nanoparticles with different diameters (5–50 nm) (A). (Figure 5A was reprinted with permission from [53], Copyright 2013 American

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• materials [7][8], such as Au nanoparticles (AuNPs), in photodynamic therapy [9][10][11]. Metal nanoparticles in general have been extensively explored in PPT applications due to their high free electron density and the possibility of intricate tuning of light absorption [12]. Noble metal nanoparticles with

•  15. Au nanoparticles have been extensively used for PT applications because of the possible intricate control of morphology (and hence absorbance), the chemical stability, and the obvious plasmon-enhanced heat transfer that does not occur in low-cost, yet ineffective, non-plasmonic materials such as

• ]. Careful studies done on plasmonic Au nanoparticles revealed the different mechanisms that can lead to vapour formation in steam generation. Particularly, the influence of the irradiance intensity on two contrasting mechanisms, namely explosive boiling and plasmonic nanobubble formation has been revealed

Formation of nanoflowers: Au and Ni silicide cores surrounded by SiO_x branches

• Feitao Li,
• Siyao Wan,
• Dong Wang and
• Peter Schaaf

Beilstein J. Nanotechnol. 2023, 14, 133–140, doi:10.3762/bjnano.14.14

• to developing different kinds of nanofabrication methods during the past decades. For example, silicon oxide (SiOx) nanostructures can be grown by the catalyzing effect of Au nanoparticles based on the vapor–liquid–solid (VLS) mechanism [1][2][3][4]. Au–SiOx nanoflowers consisting of Au nanoparticles

• and surrounding SiOx nanowires (NWs) show a significant enhancement of the photoluminescence (PL) emission compared with pure SiOx NWs due to the coupling effect between the local surface plasmon resonance (LSPR) of Au nanoparticles and the PL emission of SiOx [2]. Similar Au–SiOx nanoflowers have

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

• Vishal Dutta,
• Ankush Chauhan,
• Ritesh Verma,
• C. Gopalkrishnan and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109

• potential role of Au nanoparticles in the S-scheme heterostructure is noteworthy. They serve as a co-catalyst for improving electron separation and transmission due to the photogenerated potential. By forming heterojunctions, the visible-light absorption as well as the carrier separation efficiency of Bi

Design of surface nanostructures for chirality sensing based on quartz crystal microbalance

• Yinglin Ma,
• Xiangyun Xiao and
• Qingmin Ji

Beilstein J. Nanotechnol. 2022, 13, 1201–1219, doi:10.3762/bjnano.13.100

• nanoparticles [124]. Zhang et al. used ʟ-cysteine modified Au nanoparticles for chiral recognition of carnitine [125]. Jafari et al. used chitosan modified Ag nanoparticles for chiral sensing of tryptophan enantiomers [126]. Niu et al. reported the chiral recognition of tryptophan (Trp) on chiral Au facets

Rapid controlled synthesis of gold–platinum nanorods with excellent photothermal properties under 808 nm excitation

• Jialin Wang,
• Qianqian Duan,
• Min Yang,
• Boye Zhang,
• Li Guo,
• Pengcui Li,
• Wendong Zhang and
• Shengbo Sang

Beilstein J. Nanotechnol. 2021, 12, 462–472, doi:10.3762/bjnano.12.37

• during heating [15][16]. Pt nanoparticles have better light and thermal stability then Au nanoparticles [17]. Au–Pt bimetal nanoparticles may not only further enrich the functions of nanostructures, but the spatial distribution of both elements also plays an important role in adjusting the properties

The role of gold atom concentration in the formation of Cu–Au nanoparticles from the gas phase

• Yuri Ya. Gafner,
• Svetlana L. Gafner,
• Darya A. Ryzkova and
• Andrey V. Nomoev

Beilstein J. Nanotechnol. 2021, 12, 72–81, doi:10.3762/bjnano.12.6

• 10.3762/bjnano.12.6 Abstract The synthesis of bimetallic nanoparticles need to be controlled in order to obtain particles of a desired size, spatial structure, and chemical composition. In the synthesis of the Cu–Au nanoparticles studied here, nanoparticles can be obtained through either chemical or

• composition; however, the size of the resulting particles varies significantly. To solve this issue, we studied the formation of Cu–Au nanoparticles with different chemical compositions from a gaseous medium using computer molecular dynamics (MD) simulation. The aim was to determine the effect of the

• during chemical reactions. Therefore, the relationship between the initial experimental conditions and the final result is far from explicit [2]. This fact limits the design of Cu–Au nanoparticles for various potential applications and, at the same time, contributes to their study as a model system. In

Fabrication of nano/microstructures for SERS substrates using an electrochemical method

• Jingran Zhang,
• Tianqi Jia,
• Xiaoping Li,
• Junjie Yang,
• Zhengkai Li,
• Guangfeng Shi,
• Xinming Zhang and
• Zuobin Wang

Beilstein J. Nanotechnol. 2020, 11, 1568–1576, doi:10.3762/bjnano.11.139

• . [47] employed femtosecond laser irradiation to fabricate nanorod arrayed structures decorated with Au nanoparticles. The study showed that the Raman intensity tended to decrease as the Au film thickness increased. Based on the above results, we selected Au films of 10 nm thickness for further

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• metals (Au, Pt, Pd, Cu, and Ir) were investigated to derive a set of technologies as platform for specific applications. Especially, the shape of the 3D structures and the resulting reflectance have been investigated. The Si nanostructures fabricated using Au nanoparticles show a perfect light absorption

• the H2 formation during the silicon etching. This indicates that the reactions are at least partially within the second etching regime (where n = 2). Figure 3 shows a microscope image of a wafer with Au nanoparticles after wet etching. The PMMA masking layer is still on top of the wafer. The resist

• slope on the structure edge is clearly visible. Although the wafer surface is entirely covered with Au nanoparticles, just the pre-defined quadratic areas are etched. The etched areas appear dark black as expected for high aspect ratio silicon nanowire arrays. This absorption phenomenom has been

Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• . Specifically, we demonstrate that the TiO2 background pressure during pulsed laser deposition and the annealing conditions offer control over the formation of Au nanoparticles with different sizes, shapes and distributions, yielding a versatile sensor. We have exploited the surface for the detection of 17β

• -estradiol, an emerging contaminant in environmental waters. We have found a limit of detection of 1 nM with a sensitivity allowing for a dynamic range of five orders of magnitude (up to 100 µM). Keywords: aptamer; Au nanoparticles; 17-β estradiol (E2); plasmonics; sensor; surface-enhanced Raman scattering

Identification of physicochemical properties that modulate nanoparticle aggregation in blood

• Ludovica Soddu,
• Duong N. Trinh,
• Eimear Dunne,
• Dermot Kenny,
• Giorgia Bernardini,
• Ida Kokalari,
• Arianna Marucco,
• Marco P. Monopoli and
• Ivana Fenoglio

Beilstein J. Nanotechnol. 2020, 11, 550–567, doi:10.3762/bjnano.11.44

• CNPs and large CNP at all plasma concentrations tested, while in the case of small CNPs, aggregation was observed only with 10% of plasma, corresponding to the condition used in in vitro tests, but not in vivo. The latter is in agreement with that recently found on Au nanoparticles by Ho and co-workers

Luminescent gold nanoclusters for bioimaging applications

• Nonappa

Beilstein J. Nanotechnol. 2020, 11, 533–546, doi:10.3762/bjnano.11.42

• citrate reduction of Au(III) salts resulting in core–shell (IO@Au) nanoparticles of 9.3 ± 2.6 nm. The core–shell particles underwent lysozyme-mediated aggregation (IO@Au-Lys). The aggregated structures were further treated with Au-BSA NCs (IO@Au-Lys-Au-BSA) to form a composite structure. The combination

Evolution of Ag nanostructures created from thin films: UV–vis absorption and its theoretical predictions

• Robert Kozioł,
• Marcin Łapiński,
• Paweł Syty,
• Damian Koszelow,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2020, 11, 494–507, doi:10.3762/bjnano.11.40

• , which allows for a number of additional applications in comparison with similar Au nanoparticles, which have a maximum at around 530 nm [6]. The resonance position is influenced, for example, by size and shape of the nanoparticles and the surrounding medium. This gives the ability to control the

The effect of heat treatment on the morphology and mobility of Au nanoparticles

• Sven Oras,
• Sergei Vlassov,
• Simon Vigonski,
• Boris Polyakov,
• Mikk Antsov,
• Vahur Zadin,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2020, 11, 61–67, doi:10.3762/bjnano.11.6

• , Latvia 10.3762/bjnano.11.6 Abstract In the present paper, we investigate the effect of heat treatment on the geometry and mobility of Au nanoparticles (NPs) on a Si substrate. Chemically synthesized Au NPs of diameter ranging from 5 to 27 nm were annealed at 200, 400, 600 and 800 °C for 1 h. A change in

• particles became immovable again. This effect was attributed to the diffusion of Au into the Si substrate and to the growth of the SiO2 layer. Keywords: annealing; atomic force microscopy (AFM); Au nanoparticles; manipulation; melting; nanotribology; Introduction Gold is one of the most prominent

• materials used in studies related to nanostructures. The small size and the enhanced properties of Au nanoparticles (NPs) compared to bulk gold make them important for the development of novel applications, for example, in the field of drug delivery [1], sensor technology [2], printing [3] and catalysis [4

Gold and silver dichroic nanocomposite in the quest for 3D printing the Lycurgus cup

• Lars Kool,
• Floris Dekker,
• Anton Bunschoten,
• Glen J. Smales,
• Brian R. Pauw,
• Aldrik H. Velders and
• Vittorio Saggiomo

Beilstein J. Nanotechnol. 2020, 11, 16–23, doi:10.3762/bjnano.11.2

• micrographs of Ag and Au nanoparticles, SAXS data, pictures of the Lycurgus cup under different illumination, transmission and reflectance spectra of AuNP/AgNP @PVA nanocomposites. Supporting Information File 39: Video of dichroic Ag nanoparticles and 3D printed nanocomposites. Supporting Information File 40

Formation of metal/semiconductor Cu–Si composite nanostructures

• Natalya V. Yumozhapova,
• Andrey V. Nomoev,
• Vyacheslav V. Syzrantsev and
• Erzhena C. Khartaeva

Beilstein J. Nanotechnol. 2019, 10, 2497–2504, doi:10.3762/bjnano.10.240

• Mie scattering theory, investigated the optical response of the obtained Si/Au nanoparticles. The results of the study showed an increase of the local electric field and unidirectional light scattering with a high Purcell coefficient compared with a nanoparticle consisting only of gold. Another

• core–shell nanoparticles upon the condensation of silicon atoms onto the core when a copper nanocluster is introduced into a gaseous medium consisting of silicon atoms. In [22], similar particles were obtained by laser ablation of Au nanoparticles onto larger Co-oxide particles and agglomeration with a

Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

• Nadra Bohli,
• Meryem Belkilani,
• Juan Casanova-Chafer,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2019, 10, 2364–2373, doi:10.3762/bjnano.10.227

• characterisation Transmission electron microscopy characterisation In order to carry out high-resolution transmission electron microscope characterisation, MWCNTs were deposited onto a silicon substrate. Then, a sputtering process was conducted to deposit the Au nanoparticles. Afterwards, Au-decorated MWCNTs were

• openings efficiently [23][24]. In fact, in Figure 2a we see that CNTs with a higher number of Au nanoparticles were at the surface of the CNT mat while those showing fewer particles were deeper in the CNT film. Also, in Figure 2c, we can observe a nanotube that crosses the centre of the image where all of

• sensor before and after the HDT deposition. HRTEM image of MWCNTs decorated with Au nanoparticles at a magnification of (a) 300 K, (b) 600 K and (c) 400 K. Infrared spectra of Au-MWCNT and SAM/Au-MWCNT layers. Au-MWCNT sensor response for different concentrations of the injected vapours of (a) toluene

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• photosensitization of MoS2 and the stable interface between the two phases could promote the transfer of electrons from MoS2 to (001)-TiO2 and enhance its visible-light response [16]. It was also demonstrated that Au nanoparticles deposited on the surface of (001)-TiO2 particles could promote the separation of photo

Porous silver-coated pNIPAM-co-AAc hydrogel nanocapsules

• William W. Bryan,
• Riddhiman Medhi,
• Maria D. Marquez,
• Supparesk Rittikulsittichai,
• Michael Tran and
• T. Randall Lee

Beilstein J. Nanotechnol. 2019, 10, 1973–1982, doi:10.3762/bjnano.10.194

• silver nanocapsules with pNIPAM-co-AAc hydrogel cores. The Au nanoparticles act as nucleation sites (templating agents) for the growth of the Ag shells. Without these templating agents, the core–shell particles fail to form, leading to the exclusive formation of free metal particles and aggregated

• particles. Additionally, THPC can act as both a reducing agent and a stabilizing ligand [77]. THPC is known to produce small, uniformly spherical Au nanoparticles, which is critical for the growth of morphologically smooth Au nanoshells [87]. Given the successful use of THPC-Au seeds for growing Au shells

Growth dynamics and light scattering of gold nanoparticles in situ synthesized at high concentration in thin polymer films

• Corentin Guyot,
• Philippe Vandestrick,
• Ingrid Marenne,
• Olivier Deparis and
• Michel Voué

Beilstein J. Nanotechnol. 2019, 10, 1768–1777, doi:10.3762/bjnano.10.172

• pattern corresponding to local modifications of the optical properties of the film gradually appeared, which turned out to be the signature of the growth of the Au nanoparticles. Moreover, the monitoring of the statistical distribution of the ellipsometric angles during annealing helped evidencing two

Kelvin probe force microscopy of the nanoscale electrical surface potential barrier of metal/semiconductor interfaces in ambient atmosphere

• Petr Knotek,
• Tomáš Plecháček,
• Jan Smolík,
• Petr Kutálek,
• Filip Dvořák,
• Milan Vlček,
• Jiří Navrátil and
• Čestmír Drašar

Beilstein J. Nanotechnol. 2019, 10, 1401–1411, doi:10.3762/bjnano.10.138

• crystals of 10–20 mm in length, 3–6 mm in width and up to 3 mm in thickness [31]. The surface of freshly cleaved layered Bi2Se3 single crystals was used as a substrate. The samples for the AFM measurement, Au nanoparticles (NPs) and thin films of gold or molybdenum, were prepared via DC sputtering in a SEM

• Coating System (Bio-Rad) in Ar atmosphere (p ≈ 20 Pa, I = 18 mA, U = 1.4 kV) from pure metal sheets (Mo 4N, Au 4N). For preparing separated Au nanoparticles under the same sputtering conditions, however, a stainless steel mask (system of 100 × 500 μm2 holes, 200 holes/cm2) between the substrate and target

• . This observation can be attributed to quantum size effects [36][44], which are accompanied by a change in the charge transfer from substrate to NPs [45][46]. Metal layers on Bi2Se3 The dependence of the surface contact potential on the size of the separated Au nanoparticles theoretically allows for an

Construction of a 0D/1D composite based on Au nanoparticles/CuBi₂O₄ microrods for efficient visible-light-driven photocatalytic activity

• Weilong Shi,
• Mingyang Li,
• Hongji Ren,
• Feng Guo,
• Xiliu Huang,
• Yu Shi and
• Yubin Tang

Beilstein J. Nanotechnol. 2019, 10, 1360–1367, doi:10.3762/bjnano.10.134

• photocatalyst consisting of Au nanoparticles (NPs) and CuBi2O4 microrods (Au/CBO) was designed and prepared by a simple thermal reduction–precipitation approach. It shows excellent photocatalytic performance in the degradation of tetracycline (TC). The maximum photocatalytic degradation rate constant for Au/CBO

• , enhancing photoresponse and providing more active sites. Our work shows a possible design of efficient photocatalysts for environmental remediation. Keywords: Au nanoparticles; 0D/1D composite; CuBi2O4 microrods; photocatalysis; photocatalytic degradation; Introduction Heterogeneous semiconductor

• dissolved in distilled water (70 mL) and constantly stirred for 3 h. Then, the mixed precursor was transferred into a 100 mL steel autoclave and heated for 24 h at 180 °C. The precipitate was washed with distilled water, and dried at 60 °C for 12 h to obtain the CBO microrods. Au nanoparticles were loaded

Correlation of surface-enhanced Raman scattering (SERS) with the surface density of gold nanoparticles: evaluation of the critical number of SERS tags for a detectable signal

• Vincenzo Amendola

Beilstein J. Nanotechnol. 2019, 10, 1016–1023, doi:10.3762/bjnano.10.102

• plasmonic nanoparticles dispersed on a substrate [38], inside microcavities [39], or even while monitoring electrochemical reactions [40]. This work reports on the study of SERS tags obtained by laser ablation synthesis in liquid solution (LASiS) of gold (Au) nanoparticles, their coating with three

• 100 s. Numerical calculations The local field, Eloc, was calculated with the discrete dipole approximation (DDA) method using the software DDSCAT 7.1 and the related DDFIELD code [44][45][46]. A nanoaggregate of Au nanoparticles was created with same structure taken from a representative TEM picture

• interdipole spacing much smaller than the wavelength of interest [44][45][47]. Therefore, in the present case, 4 × 105 dipoles were used for the target, corresponding to an interdipole spacing of less than 0.5 nm. Results and Discussion In this study, AuNTs consist of a cluster of Au nanoparticles aggregated

Polydopamine-coated Au nanorods for targeted fluorescent cell imaging and photothermal therapy

• Boris N. Khlebtsov,
• Andrey M. Burov,
• Timofey E. Pylaev and
• Nikolai G. Khlebtsov

Beilstein J. Nanotechnol. 2019, 10, 794–803, doi:10.3762/bjnano.10.79

• provides additional potential advantages for in vivo experiments as compared to other inorganic coatings such as silica shells. It is well known [46] that the adsorption of fluorescent dyes on Au nanoparticles can induce quenching of their emission. However, in the AuNRs-PDA-R123-folate, the PDA layer

Biomimetic synthesis of Ag-coated glasswing butterfly arrays as ultra-sensitive SERS substrates for efficient trace detection of pesticides

• Guochao Shi,
• Mingli Wang,
• Yanying Zhu,
• Yuhong Wang,
• Xiaoya Yan,
• Xin Sun,
• Haijun Xu and
• Wanli Ma

Beilstein J. Nanotechnol. 2019, 10, 578–588, doi:10.3762/bjnano.10.59

• develop SERS substrates. Metal plasmonic nanostructures with specific shapes such as Au nanorods [9], Au nanostars [10], Ag nanocubes [11], porous Au nanoparticles [12] and pyramidal Ag [13] have been successfully synthesized by wet-chemical approaches. These plasmonic nanostructures can be used as SERS

• ]. Likewise, Chamuah et al. employed cleaned diatom frustules as bio-templates for the self-assembly of Au nanoparticles that, when used as a SERS-active substrate, provided a LOD of 1 nM for MG with a relative standard deviation (RSD) value of 7.57% [21]. Pannico and co-workers proved that it was cost