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In this work, we have implemented the time-dependent density functional theory approximate auxiliary s function (TDDFT-aas) method, which is an approximate TDDFT method. Instead of calculating the exact two-center electron integrals in the K coupling matrix when solving the Casida equation, we approximate the integrals, thereby reducing the computational cost. In contrast to the related TDDFT plus tight-binding (TDDFT+TB) method, a new type of gamma function is used in the coupling matrix that does not depend on the tight-binding parameters. The calculated absorption spectra of silver and gold nanoparticles using TDDFT-aas show good agreement with TDDFT and TDDFT+TB results. In addition, we have implemented the analytical excited-state gradients for the TDDFT-aas method, which makes it possible to calculate the emission energy of molecular systems. [ABSTRACT FROM AUTHOR]

Electrocatalytic CO2 reduction reaction (CO2RR) for CH4 production presents a promising strategy to address carbon neutrality, and the incorporation of a second metal has been proven effective in enhancing catalyst performance. Nevertheless, there remains limited comprehension regarding the fundamental factors responsible for the improved performance. Herein, the critical role of Pd in electrocatalytic CO2 reduction to CH4 on Cu-based catalysts has been revealed at a molecular level using in situ surface-enhanced Raman spectroscopy (SERS). A "borrowing" SERS strategy has been developed by depositing Cu–Pd overlayers on plasmonic Au nanoparticles to achieve the in situ monitoring of the dynamic change of the intermediate during CO2RR. Electrochemical tests demonstrate that Pd incorporation significantly enhances selectivity toward CH4 production, and the Faradaic efficiency (FE) of CH4 is more than two times higher than that for the catalysts without Pd. The key intermediates, including *CO2−, *CO, and *OH, have been directly identified under CO2RR conditions, and their evolution with the electrochemical environments has been determined. It is found that Pd incorporation promotes the activation of both CO2 and H2O molecules and accelerates the formation of abundant active *CO and hydrogen species, thus enhancing the CH4 selectivity. This work offers fundamental insights into the understanding of the molecular mechanism of CO2RR and opens up possibilities for designing more efficient electrocatalysts. [ABSTRACT FROM AUTHOR]

Photosensitization of semiconductors by excitation of chiral plasmonic metallic nanostructures has attracted much attention, not only for the analysis and detection of circularly polarized light but also for its potential applications in chiral photosynthesis. Although there have been reports on the detection of semiconductor-sensitized current in chiral nanostructures precisely fabricated by physical vapor deposition and/or lithography techniques, there have been no studies using plasmonic metal nanocolloids synthesized by chemical processes. In this study, we report the establishment of a fabrication method for large-area chiral photoelectrodes and the semiconductor photosensitization phenomenon realized using chiral plasmonic nanoparticles. Chiral plasmonic Au nanoparticles prepared by previously reported colloidal methods were immobilized onto a TiO2 thin film electrode by electrophoresis. When TiO2 electrodes loaded with chiral Au nanoparticles synthesized using L-cysteine were irradiated with circularly polarized light, left circularly polarized light irradiation at a wavelength of 500–600 nm generated a larger anodic photocurrent than right circularly polarized light irradiation at the same wavelength. This trend was reversed for TiO2 electrodes immobilized with colloidal Au nanoparticles synthesized with D-cysteine. From these results, we conclude that the efficiency of photocurrent generation by chiral plasmon excitation can be controlled by the polarization direction of the incident light. [ABSTRACT FROM AUTHOR]

We energetically predict the morphology of Pd, Ag, Au, and Pt nanoparticles on (0001) sapphire substrates, using density functional theory (DFT) simulations and the well-known Young–Dupre equation. In all cases, the contact angles exceed 90 ° , indicating that the nanoparticles are spherical. Notably, Au nanoparticles exhibit a higher contact angle than those of their counterparts. The validity of the proposed a b i n i t i o nanoparticle morphology prediction approach based on DFT simulations was assessed in comparison with our previous experimental findings pertaining to the time variation of the full width at half maximum (FWHM) of the resonant peak. Furthermore, the diffusivities of single Pd, Ag, Au, and Pt atoms on the substrate were evaluated by calculating the activation energy, offering insights into the underlying physics governing the timing of FWHM peaks. The analysis confirms a higher diffusivity of Au and Ag compared with Pd and Pt. According to the comparison between DFT and experiment results, although no clear relation is observed between the contact angles and timing of FWHM peaks, the diffusivity of sputtered atoms may influence the timing of FWHM peaks. Thus, timing can help to clarify the nanoparticle size, rather than shape. [ABSTRACT FROM AUTHOR]

The surface-enhanced Raman scattering (SERS) technique provides outstanding molecular fingerprint identification and high sensitivity of analytes. Herein, colloidal sphere-shaped gold nanoparticles (Au-NPs) trapped in concentric rings of the Bessel beam generated from the optical fiber-based negative axicon has been reported as a SERS substrate. With the trapping of Au-NPs, the SERS ability of colloidal Au-NPs improved, and the average enhancement factor (AEF) of the rhodamine-6G (R6G) and 4-aminothiophenol (4-ATP) molecules can reach up to the order of 107. Control experiments were also carried out with the trapping of Au-NPs by Gaussian beam illumination, without any illumination of the light and with the trapping of Au-NPs by the Bessel beam illumination on a silver (Ag)-coated silicon (Si) substrate with a self-assembled monolayer (SAM) of 4-ATP. Theoretical studies were also carried out using the finite element method (FEM) to identify the hotspots generated in the gaps formed between the Au-NPs, leading to an enhancement in the SERS signal of the molecules, and the results were consistent with the experimentally determined AEFs. The obtained results demonstrate that the proposed SERS technique is stable. This study has significant potential applications in clinical diagnosis, food safety, environment safety, chemical sensing, and biosensing. [ABSTRACT FROM AUTHOR]

Understanding the influence of a crowded intracellular environment on the structure and solvation of DNA functionalized gold nanoparticles (ss-DNA AuNP) is necessary for designing applications in nanomedicine. In this study, the effect of single (Gly, Ser, Lys) and mixture of amino acids (Gly+Ser, Gly+Lys, Ser+Lys) at crowded concentrations is examined on the structure of the ss-DNA AuNP using molecular dynamics simulations. Using the structural estimators such as pair correlation functions and ligand shell positional fluctuations, the solvation entropy is estimated. Combining the AuNP–solvent interaction energy with the solvation entropy estimates, the free energy of solvation of the AuNP in crowded solutions is computed. The solvation entropy favours the solvation free energy which becomes more favourable for larger effective size of AuNP in crowded solutions relative to that in water. The effective size of AuNP depends on the different propensity of the crowders to adsorb on Au surface, with the smallest crowder (Gly) having the highest propensity inducing the least effective AuNP size as compared to other single crowder solutions. In mixed crowded solutions of amino acids of variable size and chemistry, distinctive local adsorption of the crowders on the gold surface is observed that controls the additive or non-additive crowding effects which govern an increase (in Gly+Ser) or decrease (in Gly+Lys) in nanoparticle effective size respectively. The results shed light into the fundamental understanding of the influence of intracellular crowding on structure of ss-DNA AuNP and plausible employability of crowding as a tool to design programmable self-assembly of functionalized nanoparticles. [ABSTRACT FROM AUTHOR]

Modeling light–matter interactions in hybrid plasmonic materials is vital to their widening relevance from optoelectronics to photocatalysis. Here, we explore photoluminescence (PL) from ZnO nanorods (ZNRs) embedded with gold nanoparticles (Au NPs). A progressive increase in Au NP concentration introduces significant structural disorder and defects in ZNRs, which paradoxically quenches defect related visible PL while intensifying the near band edge (NBE) emission. Under UV excitation, the simulated semi-classical model realizes PL from ZnO with sub-bandgap defect states, eliciting visible emissions that are absorbed by Au NPs to generate a non-equilibrium hot carrier distribution. The photo-stimulated hot carriers, transferred to ZnO, substantially modify its steady-state luminescence, reducing NBE emission lifetime and altering the abundance of ionized defect states, finally reducing visible emission. The simulations show that the change in the interfacial band bending at the Au–ZnO interface under optical illumination facilitates charge transfer between the components. This work provides a general foundation to observe and model the hot carrier dynamics and strong light–matter interactions in hybrid plasmonic systems. [ABSTRACT FROM AUTHOR]

Exocytosis is a critical factor for designing efficient nanocarriers and determining cytotoxicity. However, the research on the exocytosis mechanism of nanoparticles, especially the role of long non-coding RNAs (lncRNA), has not been reported. In this study, the exocytosis of AuNPs in the KYSE70 cells and the involved molecular pathways of exocytosis are analyzed. It demonstrates that nanoparticles underwent time-dependent release from the cells by exocytosis, and the release of β-hexosaminidase confirms that AuNPs are excreted through lysosomes. Mechanistic studies reveal that lncRNA ESCCAL-1 plays a vital role in controlling the exocytosis of AuNPs through activation of the MAPK pathway, including the phosphorylation of ERK and JNK. The study implies that the ESCCAL-1-mediated pathway plays an important role in the exocytosis of AuNPs in KYSE70 cells. This finding has implications for the role of ESCCAL-1 on the drug resistance of esophagus cancer by controlling lysosome-mediated exocytosis.

We examine the aggregation behavior of AuNPs of different sizes on graphene as function of temperature using molecular dynamic simulations with Reax Force Field. In addition, the consequences of such aggregation on the morphology of AuNPs and the charge transfer behavior of AuNP-Graphene hybrid structure are analyzed. The aggregation of AuNPs on graphene is confirmed from the center of mass distance calculation. The simulation results indicate that the size of AuNPs and temperature significantly affect the aggregation behavior of AuNPs on graphene. The strain calculation showed that shape of AuNPs changes due to the aggregation and the smaller size AuNPs on graphene exhibit more shape changes than larger AuNPs at all the temperatures studies in this work. The charge transfer calculation reveals that, the magnitude of charge transfer is higher for larger AuNPs-graphene composite when compared with smaller AuNPs-graphene composite. The charge transfer trend and the trends seen in the number of Au atoms directly in touch with graphene are identical. Hence, our results conclude that, quantity of Au atoms directly in contact with graphene during aggregation is primarily facilitates charge transfer between AuNPs and graphene. Our results on the size dependent strain and charge transfer characteristics of AuNPs will aid in the development of AuNPs-graphene composites for sensor applications. [ABSTRACT FROM AUTHOR]

Photoinduced force microscopy (PiFM) is a technique for nanoscale characterization of optically active materials. For correct data analysis, it is important to understand and recognize potential artifacts. In this study, we provide a Fourier-based framework for the different origins of the photoinduced force, including the photothermal motion of the atomic force microscopy (AFM) tip in PiFM measurements. We use individual gold nanoparticles as a model system to explore such tip-related phenomena and to demonstrate the benefits of three-dimensional analysis of the photoinduced force. Comparison of the in-phase heterodyne PiFM signal and the derivative of the tip–sample interaction, ∂ ⟨ k ts ⟩ / ∂ z c , directly reveals a photothermal origin for the PiFM signal in our experiments. Furthermore, we observe a lateral photothermal vibration of the tip apex induced by tip asymmetry. This lateral vibration emphasizes the importance of considering the motion of the AFM tip during data analysis. The improved lateral resolution conferred by ∂ ⟨ k ts ⟩ / ∂ z c can lead to misinterpretation. Our findings highlight that meticulous data analysis is required to ensure the correct interpretation of PiFM data. [ABSTRACT FROM AUTHOR]

Developing successful nanomedicine hinges on regulating nanoparticle surface interactions within biological systems, particularly in intravenous nanotherapeutics. We harnessed the surface interactions of gold nanoparticles (AuNPs) with serum proteins, incorporating a γ-globulin (γG) hard surface corona and chemically conjugating Doxorubicin to create an innovative hybrid anticancer nanobioconjugate, Dox-γG-AuNPs. γG (with an isoelectric point of ~7.2) enhances cellular uptake and exhibits pH-sensitive behaviour, favouring targeted cancer cell drug delivery. In cell line studies, Dox-γG-AuNPs demonstrated a 10-fold higher cytotoxic potency compared to equivalent doxorubicin concentrations, with drug release favoured at pH 5.5 due to the γ-globulin coronas inherent pH sensitivity. This bioinspired approach presents a novel strategy for designing hybrid anticancer therapeutics. Our study also explored the intricacies of the p53-mediated ROS pathways role in regulating cell fate, including apoptosis and necrosis, in response to these treatments. The pathways delicate balance of ROS emerged as a critical determinant, warranting further investigation to elucidate its mechanisms and implications. Overall, leveraging the robust γ-globulin protein corona on AuNPs enhances biostability in harsh serum conditions, augments anticancer potential within pH-sensitive environments, and opens promising avenues for bioinspired drug delivery and the design of novel anticancer hybrids with precise targeting capabilities.

Clinical drug administration aims to deliver drugs efficiently and safely to target tissues, organs, and cells, with the objective of enabling their therapeutic effects. Currently, the main approach to enhance a drugs effectiveness is ensuring its efficient delivery to the intended site. Due to the fact that there are still various drawbacks of traditional drug delivery methods, such as high toxicity and side effects, insufficient drug specificity, poor targeting, and poor pharmacokinetic performance, nanocarriers have emerged as a promising alternative. Nanocarriers possess significant advantages in drug delivery due to their size tunability and surface modifiability. Moreover, nano-drug delivery systems have demonstrated strong potential in terms of prolonging drug circulation time, improving bioavailability, increasing drug retention at the tumor site, decreasing drug resistance, as well as reducing the undesirable side effects of anticancer drugs. Numerous studies have focused on utilizing polysaccharides as nanodelivery carriers, developing delivery systems based on polysaccharides, or exploiting polysaccharides as tumor-targeting ligands to enhance the precision of nanoparticle delivery. These types of investigations have become commonplace in the academic literature. This review aims to elucidate the preparation methods and principles of polysaccharide gold nanocarriers. It also provides an overview of the factors that affect the loading of polysaccharide gold nanocarriers with different kinds of drugs. Additionally, it outlines the strategies employed by polysaccharide gold nanocarriers to improve the delivery efficiency of various drugs. The objective is to provide a reference for further development of research on polysaccharide gold nanodelivery systems.

Integration of hexagonal boron nitride (h-BN) with plasmonic nanostructures that possess nanoscale field confinement will enable unusual properties; hence, the manipulation and understanding of the light interactions are highly desirable. Here, we demonstrate the surface plasmonic coupling of Au nanoparticles (ANPs) with ultrathin h-BN nanosheets (BNNS) in nonspecific nanocomposites leading to a great enhancement of the Raman signal of E2g in both experimental and theoretical manner. The nanocomposites were fabricated from liquid-exfoliated atomically thin BNNS and diblock copolymer-based ANPs with excellent dispersion through a self-assembly approach. By precisely varying the size of ANPs from 3 to 9 nm, the Raman signal of BNNS was improved from 1.7 to 71. In addition, the underlying mechanism has been explored from the aspects of electromagnetic field coupling strength between the localized surface plasmons excited from ANPs and the surrounding dielectric h-BN layers, as well as the charge transfer at the BNNS/ANPs interfaces. Moreover, we also demonstrate its capability to detect dye molecules as a surface enhanced Raman scattering (SERS) substrate. This work provides a basis for the self-assembly of BNNS hierarchical nanocomposites allowing for plasmon-mediated modulation of their optoelectronic properties, thereby showing the great potential not only in the field of SERS but also in large-scale h-BN-based plasmonic devices. [ABSTRACT FROM AUTHOR]

The document is a contents list for the New Journal of Chemistry, a journal focused on new directions in chemistry. It includes various articles and papers on topics such as lithium-ion batteries, organic synthesis, photocatalysts, and nanocatalytic systems. The journal is published by The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. [Extracted from the article]

In this study, we report an experimental protocol based on gold nanoparticles (GNPs) for the selective and efficient chromogenic detection and determination of glutathione in two pharmaceutical samples, viz. Maxiliv and Glutaderm, in real time. The glucosamine hydrochloride driven hydrothermal (40 °C) wet chemical reduction of gold(III) chloride trihydrate resulted in gold sol with a ruby red color exhibiting a surface plasmon resonance (SPR) at 521 nm. The most frequent average size of these GNPs was found to be 23 nm and their concentration was evaluated to be 8.4 nM. The zeta potential measurements and interaction of these GNPs against NaCl of varying molarities indicated their long-term stability. According to SEM analysis, these GNPs exhibited a nanowire morphology and produced a categorical color change from ruby red to blue selectively with GSH in the presence of a wide range of similar analytes in real time. UV-vis, FT-IR, XPS, SEM, TEM, AFM, EDAX, DLS, zeta potential, and other techniques were used to characterize the as-synthesized GNPs and to study their interaction with glutathione. [ABSTRACT FROM AUTHOR]

Dynamic optical modulation in response to stimuli provides exciting opportunities for designing novel sensing, actuating, and authentication devices. Here, we demonstrate that the reversible swelling and deswelling of crosslinked polymer colloidal spheres in response to pH and temperature changes can be utilized to drive the assembly and disassembly of the embedded gold nanoparticles (AuNPs), inducing their plasmonic coupling and decoupling and, correspondingly, color changes. The multi‐responsive colloids are created by depositing a monolayer of AuNPs on the surface of resorcinol‐formaldehyde (RF) nanospheres, then overcoating them with an additional RF layer, followed by a seeded growth process to enlarge the AuNPs and reduce their interparticle separation to induce significant plasmonic coupling. This configuration facilitates dynamic modulation of plasmonic coupling through the reversible swelling/deswelling of the polymer spheres in response to pH and temperature changes. The rapid and repeatable transitions between coupled and decoupled plasmonic states of AuNPs enable reversible color switching when the polymer spheres are in colloidal form or embedded in hydrogel substrates. Furthermore, leveraging the photothermal effect and stimuli‐responsive plasmonic coupling of the embedded AuNPs enables the construction of hybrid hydrogel films featuring switchable anticounterfeiting patterns, showcasing the versatility and potential of this multi‐stimuli‐responsive plasmonic system. [ABSTRACT FROM AUTHOR]

Herein, a localized surface plasmon resonance‐based sensor for volatile organic compounds (VOCs) detection is developed. The sensors are fabricated as a hybrid nanostructure of gold nanoparticles coated with a tantalum oxide (TaO) thin film on a glass slide substrate through magnetron sputtering and thermal solid‐state dewetting techniques. The thickness of the TaO film varies between 10 and 70 nm. The optical properties of samples are characterized by UV‐Vis‐NIR spectrophotometry, while their morphologies are confirmed via transmission electron microscopy. The results show the shift of the minimum optical transmittance related to the TaO thickness. Electrical field simulations are performed to predict the sensitivity of the prepared samples for VOCs detection. In addition, the sensors are tested with different VOCs, including formaldehyde, isopropanol, acetone, and methanol, which show good potential for practical applications. [ABSTRACT FROM AUTHOR]

This article examines the diverse conjugation forms of AMP‐AuNP nanostructures that arise from the amalgamation of antimicrobial peptides (AMPs) and gold nanoparticles (AuNPs), as well as their prospective utility in the field of biomedicine. AMPs are a class of naturally occurring microbicidal compounds that are recognized for their wide range of inhibitory effects and distinctive modes of operation. The utilization of AuNPs in diverse biomedical applications is facilitated through the application of nanotechnology. AMP‐AuNP nanostructures exhibit diverse features through the utilization of molecular linkage techniques. The aforementioned qualities encompass the ability to expedite the process of wound healing, facilitate precise targeting through the incorporation of DNA aptamers, serve as a means for bacterial imaging, enable the use of photothermal therapy, and contribute to the advancement of prospective treatments for fungal infections. The utilization of these synthesized antimicrobial gold nanostructures in many biomedical applications holds significant promise for advancing treatments and enhancing disease management. [ABSTRACT FROM AUTHOR]

In optical materials, the development of absorbers for a wide spectrum is a focal point of research. A pivotal challenge lies in ensuring the stability and durability of optical absorbers, particularly at elevated temperatures. This study introduces a novel approach to creating absorbers with diverse colors, focusing on the synthesis and properties of black crystal wires. In contrast to black gold nanoparticle (Au NP) precipitates, which change color within hours under similar conditions, the method involves strategically trapping Au NPs within defects during the growth of single crystals. This results in black crystal wires that not only exhibit broadband absorption but also maintain exceptional stability even under prolonged exposure to high temperatures. The method also involves the controlled synthesis of colorless and red crystal wires. As a proof of concept, these stable black Au crystal wires demonstrate superior performance in photothermal conversion applications. The methodology, derived from the crystal growth process, presents a defect template that offers a novel approach to material design. Furthermore, these unique crystals, available in various colors, hold significant promise for a range of unexplored applications. [ABSTRACT FROM AUTHOR]

Rapid diagnostics are critical infectious disease tools that are designed to detect a known biomarker using antibodies specific to that biomarker. However, a way to detect unknown disease variants has not yet been achieved in a paper test format. We describe here a route to make an adaptable paper immunoassay that can detect an unknown biomarker, demonstrating it on SARS-CoV-2 variants. The immunoassay repurposes cross reactive antibodies raised against the alpha variant. Gold nanoparticles of two different colors conjugated to two different antibodies create a colorimetric signal, and machine learning of the resulting colorimetric pattern is used to train the assay to discriminate between variants of alpha and Omicron BA.5. By using principal component analysis, the colorimetric test patterns can pick up and discriminate an unknown variant that it has not encountered before, Omicron BA.1. The test has an accuracy of 100% and a potential calculated discriminatory power of 900. We show that it can be used adaptively and that it can be used to pick up emerging variants without the need to raise new antibodies. [ABSTRACT FROM AUTHOR]

A new triazene ligand was prepared by the reaction of the bulky aryl azide, TerMesN3, (2,6-bis(2,4,6-trimethylphenyl)phenyl azide), with the bulky N-heterocyclic carbene (NHC), SIPr (N,N′-2,6-bis(diisopropylphenyl)-3,4-dihydroimidazol-2-ylidene). The steric bulk of these two groups leads to perpendicular bonding of the NHC-N3 plane and the aryl group which provides immense steric crowding around the triazene core. The corresponding π-conjugated triazene ligand was utilized as a neutral, monodentate ligand which results in monomeric Cu(I)Cl, Ag(I)OTf, and Au(I)Cl complexes. Instability of the π-conjugated triazene Au(I)Cl complex was observed, even under inert conditions. When dissolved and photolyzed in THF with workup in isopropanol, the compound decomposes forming [(SIPr＝NH)2Au(I)][Au(I)Cl2] a relatively stable compound to light, moisture, and water – alongside the formation of gold nanoparticles which were characterized using scanning electron microscopy with energy dispersive spectroscopy. [ABSTRACT FROM AUTHOR]

In this work, Au/Bi2O3 was synthesized by loading Au nanoparticles (NPs) onto β-Bi2O3 by a simple solution reduction method. β-Bi2O3 was synthesized by a precipitation-thermal decomposition procedure, which results in significantly improved SERS detection limits down to 10−9 M for methylene blue (MB) and 10−7 M for methyl orange (MO) as probe molecules, comparable to those reported for the best semiconductor SERS substrates. In particular, further deposition of Au NPs (5.20% wt%) onto β-Bi2O3 results in a two-order-of-magnitude enhancement in detection sensitivity, achieving a detection limit of 10−11 M for MB and 10−9 M for MO. Under ultraviolet/visible irradiation, the Au/Bi2O3 hybrids substrate exhibits superior self-cleaning ability due to its photocatalytic degradation ability which can be applied repeatedly to the detection of pollutants. The advanced composite substrate simultaneously achieved ultra-low mass loading of Au NPs, outstanding detection performance, good reproducibility, high stability and self-cleaning ability. The development strategy of low load noble metal coupled high performance semiconductor β-Bi2O3 to obtain nano-hybrid materials provides a method to balance SERS sensitivity, cost effectiveness and operational stability, and can be synthesized in large quantities, which is a key step towards commercialization and has good reliability prospects. [ABSTRACT FROM AUTHOR]

Electrochromic visualization of latent fingermarks has already been achieved on conducting surfaces such as stainless steel. However, their enhancement on non-conducting surfaces such as glass via electrochromism has not been reported. Considering the non-conductive nature of substrates, a layer of gold was introduced to the fingermark-bearing surfaces, in which gold was used as the cathodes to assemble electrochromic devices for visualization. The contact between gold nanoparticles of the as-obtained conducting layer in the fingermark region should be affected by the height difference within the fingermark, leading to conductivity differences, which give rise to coloration differences in electrochromic devices. It is demonstrated that 1,1′-dibenzyl-4,4′-bipyridinium dichloride can be used as the electrochromic chromophore for the visualization of latent fingermarks deposited on nonconducting surfaces, and the primary and secondary characteristic information can be obtained. The electrochromic visualization herein solves the problem of electrochromically enhancing latent fingermarks on non-conducting surfaces. [ABSTRACT FROM AUTHOR]

In the realm of immune response, pro‐inflammatory cytokines play a crucial role in regulating various physiological functions. Accurate measurement of these low‐molecular‐weight proteins is essential for understanding immune function, predicting diseases, and monitoring treatment effects. Optical aptasensors with advanced nanostructures, which utilize aptamers as bio‐probes, have emerged as a promising technology for cytokine detection, offering advantages over traditional antibody‐based nanobiosensors. Aptamers, single‐stranded nucleic acids with high specificity and affinity, enable cost‐effective mass production and consistent quality. Optical biosensors incorporating aptamers exhibit stability, resistance to environmental factors, and prolonged functionality. This review explores the current methodologies and advancements in optical aptasensors for cytokine detection, highlighting their potential as robust tools in diagnostics and therapeutics. Specifically, the applications of surface plasmon resonance and fluorescence techniques in aptasensors are discussed, focusing on the innovative approaches used to enhance sensitivity and specificity in cytokine detection. Notable examples of aptasensor designs utilizing nanoparticles, Förster resonance energy transfer, and amplification strategies are presented. These designs demonstrate high affinity, specificity, and improved sensitivity in detecting pro‐inflammatory cytokines such as interferon gamma. Overall, optical aptasensors show great promise in advancing the understanding of cytokine‐related disorders and enabling effective interventions. [ABSTRACT FROM AUTHOR]

Bi 4 Ti 3 O 12 (BiTO) is a typical bismuth-layered Aurivillius ferroelectric material for its potential application in photocatalysis. In this study, Au/BiTO hybrid was fabricated by precipitating Au nanoparticles onto BiTO nanoflake using a sodium citrate reduction route. This integration has led to a remarkable enhancement in the photocatalytic efficiency, which is attributed to the synergistic coupling of piezoelectric effect of BiTO with the localized surface plasmon resonance (LSPR) of Au nanoparticles. The incorporation of Au nanoparticles onto the BiTO matrix has significantly boosted the light absorption and charge carrier separation, thereby augmenting the photocatalytic activity. Notably, Au/BiTO-2 composite exhibits exceptional photocatalytic performance, demonstrating the complete degradation of RhB within 40 min under full-spectrum light irradiation. Moreover, Au/BiTO-2 displays a robust photocatalytic action against other organic pollutants, including methyl orange (MO), ofloxacin (OFLX) and tetracycline hydrochloride (TC). Further enhancement of photocatalytic process is achieved when combing light irradiation with ultrasonic excitation. The ultrasonic waves break the static spontaneous polarization through alternating piezoelectric potential, which accelerates the catalytic reaction. The photocatalytic action rate of Au/BiTO-2 toward RhB reaches a value as high as 0.0984 min−1, which is nearly 2.3 folds increasement compared to that of pristine BiTO. The possible synergistic mechanism caused by piezoelectric effect and exciton-plasmon effect is discussed in detail. The work not only enriches our understanding of the underlying principles but also supply a new strategy to design high-performance catalysts in the field of environmental remediation and energy conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] Inkjet printing is of great interest in the preparation of optoelectronic and microelectronic devices due to its low cost, low process temperature, versatile material compatibility, and ability to precisely manufacture multi-layer devices on demand. However, interlayer solvent erosion is a typical problem that limits the printing of organic semiconductor devices with multi-layer structures. In this study, we proposed a solution to address this erosion problem by designing polystyrene- block -poly(4-vinyl pyridine)-grafted Au nanoparticles (Au@PS- b -P4VP NPs). With a colloidal ink containing the Au@PS- b -P4VP NPs, we obtained a uniform monolayer of Au nano-crystal floating gates (NCFGs) embedded in the PS- b -P4VP tunneling dielectric (TD) layer using direct-ink-writing (DIW). Significantly, PS- b -P4VP has high erosion resistance against the semiconductor ink solvent, which enables multi-layer printing. An active layer of semiconductor crystals with high crystallinity and well-orientation was obtained by DIW. Moreover, we developed a strategy to improve the quality of the TD/semiconductor interface by introducing a polystyrene intermediate layer. We show that the NCFG memory devices exhibit a low threshold voltage (<3 V), large memory window (66 V), stable endurance (>100 cycles), and long-term retention (>10 years). This study provides universal guidance for printing functional coatings and multi-layer devices. [ABSTRACT FROM AUTHOR]

Nanotechnology is a rapidly evolving field and has been extensively studied in biological applications. An understanding of the factors that influence nanoparticle diffusion in biofluids can aid in the development of diverse technologies. The development of real-time, label-free tracking technologies would allow the expansion of current knowledge of the diffusion and activity of nanoparticles. Fluorescence-based microscopy is one of the most widespread tools to monitor and track nanoparticle dynamics; however, the influence of fluorescent tags on diffusion and biological activity is still unclear. In this study, we experimentally determined the diffusion coefficient of gold nanoparticles using a label-free, optical tracking technique and evaluated the influence of protein concentration, charge and diameter on nanoparticle diffusion through biological media. We dispersed positively- and negatively-charged nanoparticles with diameters varying from 10 to 100 nm in a common cell culture media with different concentrations of serum proteins. Our results show that dynamic protein interactions influence nanoparticle diffusion in the range of serum concentrations tested. Experimental regimes to obtain quantitative information on the factors that influence the dynamics of nanoparticles in biological media have been developed. [ABSTRACT FROM AUTHOR]

A new approach to control the n‐doping reaction of organic semiconductors is reported using surface‐functionalized gold nanoparticles (f‐AuNPs) with alkylthiols acting as the catalyst only upon mild thermal activation. To demonstrate the versatility of this methodology, the reaction of the n‐type dopant precursor N‐DMBI‐H with several molecular and polymeric semiconductors at different temperatures with/without f‐AuNPs, vis‐à‐vis the unfunctionalized catalyst AuNPs, was investigated by spectroscopic, morphological, charge transport, and kinetic measurements as well as, computationally, the thermodynamic of catalyst activation. The combined experimental and theoretical data demonstrate that while f‐AuNPs is inactive at room temperature both in solution and in the solid state, catalyst activation occurs rapidly at mild temperatures (~70 °C) and the doping reaction completes in few seconds affording large electrical conductivities (~10–140 S cm−1). The implementation of this methodology enables the use of semiconductor+dopant+catalyst solutions and will broaden the use of the corresponding n‐doped films in opto‐electronic devices such as thin‐film transistors, electrochemical transistors, solar cells, and thermoelectrics well as guide the design of new catalysts. [ABSTRACT FROM AUTHOR]

Rational design and optimization of the photocatalyst architecture, aimed at effectively enhancing light absorption and accelerating charge separation and transfer, can lead to the accomplishment of sustainable photocatalytic hydrogen production. In this study, a ternary system of Au/ZnWO4/CdS is prepared with oxygen vacancy modification through a combination of hydrothermal, chemical precipitation, and photochemical deposition methods. The addition of CdS and Au nanoparticles significantly enhances the light absorption range of ZnWO4 (ZWO) and creates more active sites for hydrogen production. The type‐II engineered heterojunction, in combination with Au as a cocatalyst, is a viable and efficient method for enhancing the separation and transport of electron–hole pairs, thereby facilitating the effective precipitation of hydrogen through photocatalysis. 5A10ZC exhibits a hydrogen production rate of 5483.62 µmol g−1 h−1, which is 167 times higher than that of unmodified ZWO and 29 times higher than that of pure CdS. In addition, it exhibits excellent cycle stability in the hydrogen production cycle stability test. The photoelectrochemical test results show that the construction of the system improves the separation and transfer efficiency of photogenerated carriers. This study provides a new inspiration for the construction of high‐performance photocatalytic materials. [ABSTRACT FROM AUTHOR]

Chemodynamic therapy (CDT) has great potential in cancer treatment, but its efficacy is limited due to non‐specificity, insufficient hydrogen peroxide (H2O2), and excessive glutathione (GSH) within the tumor microenvironment (TME). Here, an intelligent nanoplatform (Fe3O4@MnO2@NO@Au NPs, abbreviated as CD44FMNA) is reported for the treatment of breast cancer, which is constructed with Fe3O4 nanoparticles (NPs) as the core coated with manganese dioxide (MnO2) nanoshells encapsulating NO donors and gold nanoparticles (Au NPs) within the pores of MnO2, followed by the conjugation of targeting ligand anti‐CD44 mAb. The fabricated CD44FMNA initially remains inactive in normal cells, but after CD44 receptor ‐mediated MDA‐MB‐231 cell‐specific endocytosis, acidic TME can induce the decomposition of the MnO2 shell to release NO donors, thereby dually depleting the existing GSH in cells and enhancing the Fenton‐like reaction in a cascade manner. The generation of hydroxyl radicals (·OH) and the dual depletion of GSH can significantly weaken the GSH‐related antioxidant defense system (ADS) within MDA‐MB‐231 cells, accelerating apoptosis and cell death via the mitochondrial pathway. In addition, in vivo studies demonstrate that CD44FMNA can effectively inhibit tumor growth with good biosafety. Therefore, this nanoplatform may provide an effective therapy for the treatment of breast cancer. [ABSTRACT FROM AUTHOR]

Organic‐hybrid particle‐based materials are increasingly important in (opto)electronics, sensing, and catalysis due to their printability and stretchability as well as their potential for unique synergistic functional effects. However, these functional properties are often limited due to poor electronic coupling between the organic shell and the nanoparticle. N‐heterocyclic carbenes (NHCs) belong to the most promising anchors to achieve electronic delocalization across the interface, as they form robust and highly conductive bonds with metals and offer a plethora of functionalization possibilities. Despite the outstanding potential of the conductive NHC‐metal bond, synthetic challenges have so far limited its application to the improvement of colloidal stabilities, disregarding the potential of the conductive anchor. Here, NHC anchors are used to modify redox‐active gold nanoparticles (AuNPs) with conjugated triphenylamines (TPA). The resulting AuNPs exhibit excellent thermal and redox stability benefiting from the robust NHC‐gold bond. As electrochromic materials, the hybrid materials show pronounced color changes from red to dark green, a highly stable cycling stability (1000 cycles), and a fast response speed (5.6 s/2.1 s). Furthermore, TPA‐NHC@AuNP exhibits an ionization potential of 5.3 eV and a distinct out‐of‐plane conductivity, making them a promising candidate for application as hole transport layers in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Background: Oak wilt disease, caused by Bretziella fagacearum is a significant threat to oak (Quercus spp.) tree health in the United States and Eastern Canada. The disease may cause dramatic damage to natural and urban ecosystems without management. Early and accurate diagnosis followed by timely treatment increases the level of disease control success. Results: A rapid assay based on loop mediated isothermal amplification (LAMP) was first developed with fluorescence detection of B. fagacearum after 30-minute reaction time. Six different primers were designed to specifically bind and amplify the pathogen's DNA. To simplify the use of this assay in the field, gold nanoparticles (AuNPs) were designed to bind to the DNA amplicon obtained from the LAMP reaction. Upon inducing precipitation, the AuNP-amplicons settle as a red pellet visible to the naked eye, indicative of pathogen presence. Both infected and healthy red oak samples were tested using this visualization method. The assay was found to have high diagnostic sensitivity and specificity for the B. fagacearum isolate studied. Moreover, the developed assay was able to detect the pathogen in crude DNA extracts of diseased oak wood samples, which further reduced the time required to process samples. Conclusions: In summary, the LAMP assay coupled with oligonucleotide-conjugated gold nanoparticle visualization is a promising method for accurate and rapid molecular-based diagnosis of B. fagacearum in field settings. The new method can be adapted to other forest and plant diseases by simply designing new primers. [ABSTRACT FROM AUTHOR]

The document is the contents list for an issue of the journal Chemical Communications. It includes the titles and authors of various articles and features that will be included in the issue. Some of the topics covered include silk-based intelligent fibers and textiles, advances in molecular engineering of perovskite heterostructures, and metal-organic framework based self-powered devices for human body energy harvesting. The journal is published by The Royal Society of Chemistry, a leading chemistry community. [Extracted from the article]

Reversible tuning of plasmon coupling of Au nanoparticle (AuNP) agglomerates containing dimers as the main component was achieved via electrochemical surface oxidation/reduction of the AuNP surface. The system required no reactant except for water and was almost finished within a unit second, which leads to novel active plasmonic devices. [ABSTRACT FROM AUTHOR]

Materials generating circularly polarized luminescence (CPL) have received increasing interest due to their potential applications in bioimaging, sensing, anticounterfeiting, and display technologies. The possibility of efficient CPL generation is explored for organic molecules, inorganic materials, and their hybrid systems. A chiral plasmonic nanostructure is one candidate for generating strong and highly dissymmetric CPL by coupling with the surrounding luminescent material. Here, the inherent luminescence of gold nanoparticles can produce CPL without using any secondary material is suggested. In this study, the generation of circularly polarized two‐photon‐induced photoluminescence (TPI‐PL) from chiral gold nanostructures is demonstrated. Measurements of TPI‐PL show that it has a strong dissymmetry factor of ≈0.7 for a single chiral Au nanoparticle. A theoretical simulation study showed that a local chiral electromagnetic field confined to the chiral gap structures contributes to the high degree of circular polarization in TPI‐PL. It is believed that this work provides a new route for novel CPL‐generating materials with strong dissymmetry and holds promise for various applications using CPL technology. [ABSTRACT FROM AUTHOR]

We demonstrate a simple method for preparing highly active Au/TS-1 catalysts for propylene hydro-oxidation, which involves sequentially impregnating HAuCl4 and Cs2CO3 solutions onto TS-1. The Au/TS-1 catalysts synthesized by this method exhibit high Au uptake efficiency (∼100%), high dispersion of Au nanoparticles and superior activity. [ABSTRACT FROM AUTHOR]

Significance: Multilesional basal cell carcinoma (BCC) are spread on sun exposed skin areas, including arms, face and back. The first‐line treatment remains the surgical resection or Mohs surgery. Despite its high complexity, Mohs surgery is well practiced in USA and Germany and presents very good results both in esthetic and in carcinology point of view. Large lesions more than 2 cm remain challenging to remove by topical cream used in photodynamic therapy (PDT). If these larger lesions are not treated in less than 1 month, they could grow deeply in the skin, thus enhancing the risk of reoccurrence and the severity of the disease. Despite this model herein studied, that is non melanoma skin cancer is a good prognostic cancer, the therapy aims to be applied to more aggressive melanoma skin cancers. Aim: Total regression of large cutaneous lesions less than 1 month with no reoccurrence. Approach: Tumor induction on murine model bearing a 500 mm3 subcutaneous lesion. Increasing dose of gold nanoparticles at fixed initial concentration C0 = 0.3 mg/mL, infused into the tumor then exposition of the region of interest to NIR medical laser to assess the therapy. One or two intratumoral administration(s) were compared to surgery and control, that is no treatment, laser alone or nanoparticles alone. Results: Gold nanoparticles alone or the NIR laser alone did not induce the tumor regression. The combination of laser and nanoparticles called plasmonic nanophotothermal therapy induced apoptosis. Derma and hypoderm do not show any visible gold nanoparticles and demonstrated a good cicatrization process. Conclusion: Plasmonic nanophotothermal therapy using two doses of gold nanoparticles was the only protocol that proved its efficacy on large lesions in 14 days, that is 500 mm3 on a murine model bearing human basal cell carcinoma. [ABSTRACT FROM AUTHOR]

[198Au]Au@SiO2 core–shell nanoparticles ([198Au]Au@SiO2 CSNPs) were synthesized using Persea americana Mill. seed (PAS) extract as a reducing agent. The synthesis involves amino-functionalized SiO2 core formation followed by shell formation with [198Au]Au seeds attachment and a reduction process. The resulting [198Au]Au@SiO2 CSNPs, sized at 188.96 nm, exhibited near-infrared (NIR) absorption at 750 nm and radiochemical purity of 99.91%. In vitro treatment, combined with 980 nm laser irradiation at 3 W cm−2, induced hyperthermia, enhancing cell death in LNCaP cancer cells to 2.60% viability. This study highlights the potential of [198Au]Au@SiO2 CSNPs as a promising radio-photothermal therapeutic agent. [ABSTRACT FROM AUTHOR]

In this study, bioengineered and biosynthesized elastin-like polypeptide (ELP) was adopted for a non-volatile memory resistive switching device or a memristor. The ELP mimicked from elastin of mammal was synthetically produced in polypeptide by Escherichia coli gene recombination. They were composed of a repeating pentapeptide sequence having [Val-Pro-Gly-Val-Gly]32 sequence for bioelectronic devices with ELP showing multiple electrical resistance states between a high resistance state and a low resistance state through an applied electrical field. In addition, the ELP-coated 5-nm gold nanoparticles (Au NPs) layer was also to be biomaterials used for nanobiohybrid memristive devices. Simple metal–insulator–metal device structure and lateral electrode device with ELP layer on 5-nm Au NPs could show neuromorphic adaptive current–voltage (I–V) behavior and electrical stimulus-induced potentiation and depression in a hydrogel state. In addition, with an introduction of a neurotransmitter cortisol's specific antibody, a preliminary sensing protocol was also examined with the nanobiohybrid device. Therefore, the introduction of ELP into neuromorphic device is regarded as the cornerstone for the development of biocompatible bioelectronic devices that can be integrated into human bionics for future artificial neuromorphic format. [ABSTRACT FROM AUTHOR]

Current label-free surface-enhanced Raman spectroscopy (SERS) assay for the detection and analysis of organophosphorus pesticides has achieved initial success, but the application still faces constraints of substrate portability and specificity. To this end, this paper demonstrates a method for portable, rapid, and specific detection of low concentrations of fenthion pesticides based on a solid substrate of gold nanoparticle monolayers combined with molecularly imprinted polymers (MIPs). The nano-monolayers were transferred to the surface of mercapto-silicon wafers by interfacial self-assembly technique to form a stable connection with S–Au bonds and, at the same time, prevent nanoparticles from dropping off during the surfactant removal process. Then, the fenthion MIPs were directly generated on the surface of the monolayer film by spin-coating with a pre-polymerization solution and ultraviolet-induced polymerization. Tests showed that the molecular imprint was able to accurately bind to fenthion, but not other molecules, in a mixture of structural analogs, achieving a low concentration detection of 10–8 mol/L. The composite substrate maintained a signal uniformity of a relative standard deviation (RSD) = 7.05% and a batch-to-batch reproducibility of RSD = 10.40%, making it a potential pathway for the extended application of SERS technology. [ABSTRACT FROM AUTHOR]

Energy transition towards net-zero society calls for utilization of renewable power to drive CO 2 conversion in an efficient electrochemical way. The development of a commercial CO 2 electrolyzer with positive tech-eco effect calls for active and durable electrocatalysts. High-loading gold on carbon (Au/C) with reduced particle size is the prerequisite for the highly-selective and highly energy-efficient CO production in such a CO 2 electrolyzer, but a scalable synthetic method is missing. With combined control of ligand, substrate and pH value, Au/C catalysts with particle size within 5 ​nm and metal loading of 40 ​wt% and 60 ​wt% are synthesized on low and high surface-area carbon, respectively. We also provide a thorough investigation of the effect of the ligand type, surface charge of gold nanoparticles (Au NPs) and surface area of carbon substrate on the loading limit of Au/C. [Display omitted] • High loading Au/C electrocatalyst was synthesized by anchoring small Au nanoparticles onto conductive carbon substrate. • A protocol of tuning the charge between gold nanoparticles and carbon substrate by ligand selection and pH value was developed. • The gold loading on carbon was further enhanced by introducing commercial carbon with large specific surface area. [ABSTRACT FROM AUTHOR]

Arsenic contamination in environmental waters poses global health and environmental risks. This study addresses the urgent need for rapid, selective, and sensitive detection of inorganic arsenic (iAsIII) in environmental samples. Leveraging the unique properties of gold nanoparticles (AuNPs) and the selective binding affinity of homocysteine (Hcy), we developed a novel colorimetric sensor for iAsIII detection. Our investigation elucidates the mechanism by which Hcy modifies AuNPs, enabling the selective detection of iAsIII ions through chelation between amine and carboxyl groups, primarily with the predominant species H2AsO3− at pH 12.0. Our sensor achieves high selectivity (>10‐fold) for iAsIII amid various interfering ions commonly found in environmental samples. Furthermore, we demonstrate exceptional sensitivity in detecting iAsIII, with a low limit of detection (LOD) of 67 nM, aligning with regulatory standards for arsenic concentration in drinking water. The selectivity and sensitivity of our sensor were validated through experiments with various metal ions and real water samples. In conclusion, our study presents a comprehensive understanding of the mechanism, selectivity, and sensitivity of Hcy‐modified AuNPs in detecting iAsIII, offering a versatile nanosensor platform with significant implications for environmental monitoring and public health. [ABSTRACT FROM AUTHOR]

Interferon gamma (IFN‐γ) released by T lymphocytes, plays an important role in immune regulation and is also an important biomarker for the early diagnosis of bovine tuberculosis. In this work, an electrochemical immunosensor based on gold nanoparticles (AuNPs)/chitosan composite was developed for highly sensitive determination of bovine IFN‐γ. AuNPs/chitosan composite shows high surface area and good hydrophilicity. The bovine IFN‐γ immunosensor was prepared by immobilizing IFN‐γ antibody on AuNPs/chitosan composite‐modified glassy carbon electrode. The immunosensors were characterized by scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry (CV). Using horseradish peroxidase (HRP)‐labeled IFN‐γ antibody as amplification probe, the concentration of bovine IFN‐γ can be monitored via the increasing current signal, which can be attributed to the specific immune binding between bovine IFN‐γ antigen and HRP‐labeled IFN‐γ antibody, as well as the efficient catalysis reaction between thionine and HRP with the presence of H2O2. The developed electrochemical immunosensor exhibited a wide linear range of 0.01 to 30 ng/mL, and low detection limit of 0.003 ng/mL with good specificity and stability. This study provides a simple and promising method for diagnosis of bovine tuberculosis, which can be expanded to determine other biomarkers. [ABSTRACT FROM AUTHOR]

A versatile method is invented to self‐assemble gold nanoparticles (GNPs) into nanoclusters (NCs) of various morphologies. By storing the particles in toluene, a highly non‐polar solvent, under conditions that ensure particle stability, the success rate of subsequent assembly can be enhanced. Additionally, conducting particle self‐assembly at a stirring speed of 200 rpm allows the NCs to maintain a spherical shape. The relative standard deviation (RSD) of Raman spectral peaks of multiple NCs used as surface‐enhanced Raman spectroscopy (SERS) substrates is calculated to be less than 10%, effectively addressing the issue of low repeatability when using NCs as SERS substrates. Furthermore, even at an analyte concentration reduced to 10−9 m, a SERS characteristic peak intensity of approximately 2 × 103 is measurable, demonstrating the high sensitivity of the assembled structures. Finally, by detecting SERS signals from NCs of varying sizes, the intensities of characteristic peaks tend to converge, eliminating the influence of morphology and size on SERS detection. [ABSTRACT FROM AUTHOR]

Functional supramolecular materials exhibit important features including structural versatility and versatile applications. Here, this study reports the construction of unique hierarchically organized nanotoroids exhibiting fluorescence, photocatalytic, and sensing properties. The nanotoroids comprise of macrocyclic diacetylenes (MCDA) and 8‐anilino‐1‐naphthalene sulfonate (ANS), a negatively charged aromatic fluorescent dye. This study shows that the hierarchical structure of the nanotoroids consist of MCDA nanofibers formed by stacked diacetylene monomers as the basic units, which are further bent and aligned into toroidal organization by electrostatic and hydrophobic interactions with the ANS molecules. The amine moieties on the nanotoroids surface are employed for deposition of gold nanostructures – Au nanoparticles or Au nanosheets – which constitute effective platforms for photocatalysis and surface enhanced Raman scattering (SERS)‐based sensing. [ABSTRACT FROM AUTHOR]

Rare earth (RE)-doped CaS phosphors have been widely used as light-emitting components in various fields. Nevertheless, the application of nanosized CaS particles is still significantly limited by their poor water resistance and weak luminescence. Herein, a lattice-matching strategy is developed by growing an inert shell of cubic NaYF4 phase on the CaS luminescent core. Due to their similarity in crystal structure, a uniform core–shell heterostructure (CaS:Ce3+@NaYF4) can be obtained, which effectively protects the CaS:Ce3+ core from degradation in aqueous environment and enhances its luminescence intensity. As a proof of concept, a label-free aptasensor is further constructed by combining core–shell CaS:Ce3+@NaYF4 and Au nanoparticles (AuNPs) for the ultrasensitive detection of kanamycin antibiotics. Based on the efficient FRET process, the detection linear range of kanamycin spans from 100 to 1000 nM with a detection limit of 7.8 nM. Besides, the aptasensor shows excellent selectivity towards kanamycin antibiotics, and has been successfully applied to the detection of kanamycin spiked in tap water and milk samples, demonstrating its high potential for sensing applications. [ABSTRACT FROM AUTHOR]

An upconversion fluorescence sensing platform was developed with upconversion nanoparticles (UCNPs) as energy donors and gold nanoparticles (AuNPs) as energy acceptors, based on the FRET principle. They were used for quantitative detection of uranyl ions (UO22+) by amplifying the signal of the hybrid chain reaction (HCR). When UO22+ are introduced, the FRET between AuNPs and UCNPs can be modulated through a HCR in the presence of high concentrations of sodium chloride. This platform provides exceptional sensitivity, with a detection limit as low as 68 pM for UO22+ recognition. We have successfully validated the reliability of this method by analyzing authentic water samples, achieving satisfactory recoveries (89.00%–112.50%) that are comparable to those of ICP-MS. These results indicate that the developed sensing platform has the capability to identify trace UO22+ in complex environmental samples. [ABSTRACT FROM AUTHOR]

A novel biofuel cell (BFC)-based self-powered electrochemical immunosensing platform was developed by integrating the target-induced biofuel release and biogate immunoassay for ultrasensitive 17β-estradiol (E2) detection. The carbon nanocages/gold nanoparticle composite was employed in the BFCs device as the electrode material, through which bilirubin oxidase and glucose oxidase were wired to form the biocathode and bioanode, respectively. Positively charged mesoporous silica nanoparticles (PMSN) were encapsulated with glucose molecules as biofuel and subsequently coated by the negatively charged AuNPs-labelled anti-E2 antibody (AuNPs-Ab) serving as a biogate. The biogate could be opened efficiently and the trapped glucose released once the target E2 was recognized and captured by AuNPs-Ab due to the decreased adhesion between the antigen–antibody complex and PMSN. Then, glucose oxidase oxidized the glucose to produce a large number of electrons, resulting in significantly increased open-circuit voltage (EOCV). Promisingly, the proposed BFC-based self-powered immunosensor demonstrated exceptional sensitivity for the detection of E2 in the concentration range from 1.0 pg mL−1 to 10.0 ng mL −1, with a detection limit of 0.32 pg mL−1 (S/N = 3). Furthermore, the prepared BFC-based self-powered homogeneous immunosensor showed significant potential for implementation as a viable prototype for a mobile and an on-site bioassay system in food and environmental safety applications. [ABSTRACT FROM AUTHOR]

Gold nanoclusters (AuNCs) possess weak intrinsic fluorescence, limiting their sensitivity in biosensing applications. This study addresses these limitations by developing a spatially confined dual-emission nanoprobe composed of silicon nanoparticles (SiNPs) and AuNCs. This amplified and stabilized fluorescence mechanism overcomes the limitations associated with using AuNCs alone, achieving superior sensitivity in the sensing platform. The nanoprobe was successfully employed for ratiometric detection of bleomycin (BLM) in serum samples, operating at an excitation wavelength of 365 nm, with emission wavelengths at 480 nm and 580 nm. The analytical performance of the system is distinguished by a linear detection range of 0–3.5 μM, an impressive limit of detection (LOD) of 35.27 nM, and exceptional recoveries ranging from 96.80 to 105.9%. This innovative approach significantly enhances the applicability and reliability of AuNC-based biosensing in complex biological media, highlighting its superior analytical capabilities. [ABSTRACT FROM AUTHOR]