查找使用阿拉丁产品的科研文献

Au nanoparticle-decorated TiO2 nanorod array for plasmon-enhanced quantum dot sensitized solar cells

Qiqian Gao,Xueyu Zhang,Lianfeng Duan,Xuesong Li,Wei Lü

In present work, Au nanoparticle-decorated TiO 2 nanorod array composite structure is designed and fabricated as the working electrode of CdS sensitized quantum dot-sensitized solar cells (QDSSCs). The results reveal that the intensity and range of sunlight absorption, photo-generated carriers transport efficiency and overall photoelectric conversion efficiency (PCE) were significantly enhanced due to followed reasons: Hot electrons of Au NPs excited by plasmon effect can offer extra electrons; plasmonic effect can contribute to the extraction and separation of light-generated electrons; the deposition of Au nanoparticles could effectively optimize the interface between TiO 2 nanorod and CdS QDs. As a result, an overall PCE of 3.29% has been obtained, which shows 19.6% enhancement compared with pure TiO 2 nanorod photoanode .

Fabrication of MOF-derived porous Au@Co-ZnO nanostructures with excellent C2H5OH sensing performance

Kaiwen Tian,Yukang Fu,Inzimamul Haq,Shuangyang Kuang,Gaojie Xiong,Zeyuan Zhao,Tianyu Zhou,Jun Weng,Xiang Peng,Liwei Xiong

Aim: Zinc oxide (ZnO) is an n-type semiconductor with a wide bandgap, excellent electron mobility, and stable chemical characteristics, making it potentially applicable in the field of gas sensing. However, conventional ZnO-based gas sensors face challenges such as high operating temperatures and low sensitivity.Methods: In this paper, we first synthesized ZIF-8 with a rhombic dodecahedron structure using a room-temperature chemical precipitation method. By doping ZIF-8 with cobalt (Co) and exchanging gold ions, followed by calcination in air, we obtained a metal-organic framework (MOF) derived porous Au@Co-ZnO nanostructure.Results: This nanostructure retained the large specific surface area and porous characteristics of ZIF-8, while its gas sensing performance was significantly enhanced compared to the pure MOF-derived ZnO nanostructure, due to Co doping and gold nanoparticle modification. At an ethanol concentration of 100 ppm, the Au@Co-ZnO sample demonstrated its best performance at 140 °C, with a response value of 205.3. This result was 28.9 times higher compared to the pure ZnO sample, which showed a response value of 7.1 under identical conditions. Additionally, the optimal operating temperature was 40 °C lower than that of the pure ZnO sample (180 °C). Furthermore, the Au@Co-ZnO samples demonstrated good stability and selectivity for ethanol gas.Conclusion: The proposed MOF-derived porous Au@Co-ZnO nanostructures not only advance the application of MOF-derived materials in gas detection but also offer a novel approach for boosting the gas-sensing performance of other metal oxide materials.

Ag@Au nanoparticle solid arrays for enhanced SERS detection of enrofloxacin: FDTD simulation insights

Cheng Yuliang,Zhao Yajie,Li Peizhen,Yu Hang,Xie Yunfei,Guo Yahui,Yao Weirong,Qian He

As one of the most extensively used antibiotics in aquaculture in China, enrofloxacin (ENR) tends to accumulate in human body and endanger people’s health. Rapid, sensitive, and facile assays for enrofloxacin are urgently needed. In this study, based on the solid-phase substrate preparation strategy combined with microsphere etching and magnetron sputtering, Ag@Au nanoparticle (Ag@Au NP) solid array (Ag@Au NSA) with high surface-enhanced Raman spectroscopy (SERS) enhancement factor (EF≈8.3 × 10 7 ) was developed. Finite-difference time-domain (FDTD) simulations revealed that the Ag@Au NSA achieved maximum electromagnetic enhancement (EM) under the following optimized conditions: 633 nm excitation wavelength, 7.9 nm Au shell thickness, and 30.5 nm Ag core size. Additionally, SERS mapping results confirmed both the excellent enhancement performance and signal reproducibility of Ag@Au NSA, due to the expected micro-region enhancement with long-term effects accompanied by a larger range of high-density “hot spots.” The proposed SERS sensing for ENR based on Ag@Au NSA had a limit of detection (LOD) of 0.076 ng/mL ( R 2 ≈ 0. 9991) and was further applied to real-sample detection of ENR in crayfish tail meat with good recoveries ranging from 91.36 to 112.60%, indicating its great potential in practice. Graphical

Mutual connection between extinction and morphology revealing growth evolution of Janus Mn:Ag2Se-Au nanostructures

Si-Ting Liu,Jia-Yi Zhang,Yu Zhou,Zhen-Long Dou,Cong-Cong Zhang,Si-Jing Ding,Qu-Quan Wang,Li Zhou

This paper presents a mechanistic study on the synthesis of Janus Mn:Ag2Se-Au heterogeneous nanostructures based on a step-by-step protocol. The extinction spectra and morphological observations exhibit interrelated data that elucidate the initial formation and subsequent evolution of growing Mn-doped Ag2Se domains onto Au nanoparticles. The size and morphology of the Mn:Ag2Se-Au can be adjusted by changing the amount of AgNO3. In addition, excessive Se source will generate a sparse Se shell around the Janus Mn:Ag2Se-Au. The characteristic plasmon resonance and photoluminescence attributes of Janus Mn:Ag2Se-Au render it a promising candidate for applications in the fields of sensing and imaging.

Targeting threonine deaminase with chiral Au NPs: A novel strategy for E. coli inhibition

He Wang,Haidu Yuan,Jianhao Zhang,Wenjing Yan

Bacterial infections are becoming a significant threat to global human health due to the growing prevalence of biofilm-related infections and the rise in antibiotic resistance. D/ l -cysteine functionalized chiral gold nanoparticles (D/P-Au NPs or L/P-Au NPs) have demonstrated a potent antibacterial effect against E. coli , while the mechanism remains to be elucidated through additional research. Threonine deaminase (TD) is a crucial enzyme involved in branched-chain amino acid (BCAA) biosynthesis in E. coli and is involved in cysteine's antimicrobial effects. This study investigated the interaction between chiral Au NPs (D/P-Au NPs or L/P-Au NPs) and TD as well as its effect on enzyme activity. It demonstrates that chiral Au NPs interact with TD through hydrophobic forces, forming a ground state complex that induces changes in the secondary structure of TD and reduces enzyme activity in a concentration-dependent manner. We found that the exogenous supplementation of isoleucine and valine (2 mg/mL) significantly reduced the antibacterial activity of chiral Au NPs, especially for L/P-Au NPs. The proteomics results indicate that the expression of ilvA and ilvB was down-regulated after L/P-Au NPs treatment, which would interfere with the synthesis of BCAAs. These results demonstrate that chiral Au NPs cause cell death of E. coli partly due to inhibition of TD enzyme activity and the synthesis of branched-chain amino acids.

Engineered three-dimensional Au@Ag NCs/MXene/polystyrene microsphere SERS substrate for ultrasensitive detection

Jun Dong,Yixuan Hou,Wei Gao,Chengyun Zhang,Lipeng Zhu,Yongkai Wang,Qingyan Han,Jianxia Qi

Surface-Enhanced Raman Scattering (SERS), with the exceptional single-molecule detection capability and high sensitivity, has become an advanced spectroscopic analysis method in fields such as chemical analysis and biosensing. Three-dimensional (3D) sandwich substrates, due to their unique structural characteristics, have attracted considerable attention for their ability to enhance SERS detection sensitivity. However, the controlled assembly of 3D sandwich substrates with bimetallic nanoparticles remains a challenge. In this paper, a fabrication method for constructing 3D sandwich substrates via a bottom-up approach is proposed. Using a liquid–liquid phase self-assembly method, Au@Ag nanocubes (Au@Ag NCs) were assembled on a polystyrene (PS) microsphere array with monolayer MXene (Ti 3 C 2 T X ) adsorption, successfully constructed an Au@Ag NCs/MXene/PS microsphere substrate. Furthermore, the SERS sensitivity of the substrate was evaluated using Rhodamine 6G (R6G), Crystal Violet (CV), and Aspartame (APM) molecules, and experimental results show that the detection limits are 10 −12 M, 10 −11 M, and 0.0313 g/L (1.06 × 10 −4 M), respectively, with excellent uniformity and stability of the substrate. These findings demonstrate that the constructed 3D substrate exhibits outstanding SERS performance and holds significant potential for applications in environmental pollutant detection and food safety.

High-performance, self-powered UV photodetector based on Au nanoparticles decorated ZnO/CuI heterostructure

Fa Cao,Ling Jin,Yong Wu,Xiaohong Ji

Self-powered Ultraviolet (UV) photodetectors (PDs) have attracted great attention due to their outstanding performance. Herein, we report the successful fabrication of self-powered UV PDs based on ZnO/CuI/Au heterojunction . An ultra-high on/off ratio of 4250 and fast rise/decay times of 0.41/0.08 s have been demonstrated from the ZnO/CuI/Au PD. Moreover, the PD exhibits a high responsivity of 61.5 mA/W and detectivity of 1.7 × 10 10 Jones. The device displays long-term cyclic stability with 98.9% retention after 1000 cycles continuous test and superior environmental stability with 97.1% retention tested after 6 months. The synergistic effects of plasmonic Au nanoparticles and ZnO/CuI pn heterostructure play important roles in the enhancement of the photodetect ability. The concept of employing plasmonic Au nanoparticles onto the heterostructure indicates huge potential in achieving self-powered UV PDs for practical applications.

Electrochemical Immunosensor for Aflatoxin B1 Based on Polyaniline/Graphene Nanohybrids Decorated with Au Nanoparticle

Ling SHI,Zefeng WANG,Guangming YANG,Xianlan CHEN,Gaozhang GOU,Wei LIU

Silent-region SERS detection of fatigue biomarkers based on Au@PB core-shell nanoprobes

Chuanyu Liu,Guangda Xu,Jiangheng Fan,Boya Chen,Lefa Zhao

Au@PB core-shell nanoprobes exploit the Raman silent region (2150 cm −1 ). • Signal-off SERS evades biological-matrix background in complex serum. • GOx/LOx cascades let one Au@PB reporter assay H 2 O 2 , glucose, lactate. • Detection limits reach 4.2 × 10 −10 to 1.17 × 10 −8  M for three analytes. • 91.4–106.6% serum recovery supports exercise-fatigue biomarker monitoring. Assaying exercise-related biochemical markers is important for elucidating the mechanisms of exercise metabolism and fatigue. However, conventional surface-enhanced Raman scattering (SERS) techniques are often limited by biological matrix background interference and fingerprint-region spectral overlap in complex biological fluids. To overcome these limitations, this study constructs a signal-off-type parallel SERS detection platform based on Au@PB core-shell nanostructures. The core design of the platform leverages the characteristic peak of the Prussian blue (PB) shell located in the Raman silent region (2150 cm −1 , C N stretching vibration) to avoid biological matrix background interference, and employs a signal-off mechanism in which hydrogen peroxide (H 2 O 2 ) triggers the quantitative attenuation of the PB silent-region peak intensity, enabling the same PB shell to function as both a SERS reporting unit and an H 2 O 2 -responsive unit. On this basis, H 2 O 2 , glucose (Glu), and lactate (LA) share a single signal-off-type Au@PB reporting molecule: H 2 O 2 directly triggers this attenuation, whereas Glu and LA are in situ converted into H 2 O 2 through enzymatic cascades of glucose oxidase (GOx) and lactate oxidase (LOx), respectively, which then triggers the same attenuation, thereby enabling three-target parallel analysis from a single reporter. Under optimized conditions, the platform exhibits good linearity and high sensitivity for H 2 O 2 (R 2  = 0.9953, LOD = 4.2 × 10 −10  M), Glu (R 2  = 0.9968, LOD = 3.76 × 10 −9  M), and LA (R 2  = 0.9977, LOD = 1.17 × 10 −8  M). The relative standard deviation (RSD) across 20 parallel samples is 2.8%–4.4%, and the spiked recoveries in real serum samples remain stable at 91.4%–106.6%. This anti-interference parallel analysis strategy provides a methodological basis for monitoring fatigue-related biochemical changes in real serum and demonstrates the distinctive advantages of silent-region SERS in complex biological matrix sensing. Download: Download high-res image (141KB) Download: Download full-size image

Electrochemical Capacitance of Spherical Nanoparticles Formed by Electrodeposition of Intrinsic Polypyrrole onto Au Electrode

Shaoyun Chen,Hui Liu,Yuan Wang,Shaoqin Xu,Wenfeng Liu,Dan He,Xueqing Liu,Jiyan Liu,Chenglong Hu

The conducting polypyrrole (PPy) spherical nanoparticles are synthesized by a facile electrochemical deposition method and the polymerization is carried out by potentiostatic methods using a two-electrode system (Au electrode) with a template-free method. The microstructure of the PPy spherical nanoparticles and their electrochemical properties can be tuned by controlling the electrodeposition time and anodic potential in the synthetic process. A maximum specific capacitance of 356   F/g is obtained for as-prepared PPy electrodes from cyclic voltammetry (CV) at a scan rate of 10   mV/s, which is superior or close to some individual PPy nanostructure , PPy/metal, and PPy/carbon materials. Also, the stability of cycling can retain 89.3% of its initial capacitance after 1000 cycles. The capability of fabricating stable polymer electrodes is expected to make an important contribution to the promotion of supercapacitor technology.

Dynamic Au-Thiolate Interaction Induced Rapid Self-Healing Nanocomposite Hydrogels with Remarkable Mechanical Behaviors

Haili Qin,Tan Zhang,He-Nan Li,Huai-Ping Cong,Markus Antonietti,Shu-Hong Yu

Synthetic materials capable of self-healing when damaged have attracted increasing attention and have been developing rapidly because of their many potential applications. Despite great achievements, there is an urgent need to advance the mechanical properties and reduce the time for healing simultaneously because of limited branch functionality and poor polymer mobility. Here, we report robust and smart hydrogels prepared using multi-vinyl-modified gold nanoparticles through a thiolate-gold coordination interaction as large crosslinkers. As a result of efficient energy dissipation from dynamic gold crosslinks with enhanced branching, hydrogels exhibit excellent elasticity with increased mechanical strength at high elongation, even when notched. Combined with thiolate-gold interaction as a healing motif and a notable optothermal effect of nanoparticles, hydrogels deliver rapid self-healing with optimal efficiency of nearly 96% under near-infrared irradiation in 1 min. These properties may shed light on promising applications for this kind of hydrogel in biomedicine and engineering.

Electrocatalytic Synthesis of Hydrogen Peroxide over Au/TiO2 and Electrochemical Trace of OOH* Intermediate

Zhipeng Sun,Lei Sheng,Hao Gong,Li Song,Xiaolong Jiang,Shengyao Wang,Xianguang Meng,Tao Wang,Jianping He

In this work, a series of gold-supported titanium oxide composites have been prepared and high selectivity (over 90%) of hydrogen peroxide is achieved. For the first time, electrochemical impedance spectroscopy and electron spin resonance analysis demonstrate that high charge transfer impedance of the catalyst can suppress the decomposition of OOH* intermediates thus promoting the two-electron process of the oxygen reduction reaction.