JOURNAL OF DAIRY SCIENCE
·
2022
·
IF 4.225
Bolong Fang,Juan Peng,Gan Zhang,Keyu Xing,Wenyao Chen,Daofeng Liu,Shan Shan,Yonghua Xiong,Weihua Lai
ABSTRACT Escherichia coli O157:H7 is a type of hazardous bacteria in the field of food safety. A sensitive and effective method is urgently needed to detect it, avoiding enormous harm for the human health. In this study, we synthesized stable Ag + -doped gold nanoclusters (Ag-AuNC) with a fluorescence intensity 4.8 times stronger than that of AuNC. It was further demonstrated that Ag 0 existing in the AuNC core and a fraction of Ag + anchored on the AuNC shell eliminated the surface defects and improved the luminescent properties of AuNC. A combination of I 2 and I − was used to quench fluorescence-enhanced Ag-AuNC, which was first applied in ELISA for detecting E. coli O157:H7 to improve the sensitivity. In the presence of E. coli O157:H7, the biotinylated anti- E. coli O157:H7 mAb and streptavidin-alkaline phosphatase would be immobilized and catalyze l -ascorbic acid 2-phosphate sesquimagnesium salt hydrate to produce ascorbic acid. After addition of KIO 3 , I 2 /I − were generated. The I 2 could trigger oxidative etching of Ag-AuNC and I − could combine with Ag + to decrease the Ag + concentration of Ag-AuNC, which resulted in fluorescence quenching of Ag-AuNC. Under optimal conditions, the linear range of I 2 /I − -mediated fluorescence quenching of Ag-AuNC-based immunoassay for detecting E. coli O157:H7 was 3.3 × 10 3 to 10 6 cfu/mL, with a detection limit of 9.2 × 10 2 cfu/mL, 10.7-fold lower than that of the traditional ELISA. The proposed immunoassay exhibits excellent sensitivity, specificity, recovery, and accuracy, which is useful for quantitative detection of E. coli O157:H7 in food safety.
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高影响因子
Analytical Methods
·
2020
·Vol. 12
·期 22
·2858-2864
·
IF 2.596
Xiaohui Ren,Xin Li
Flower-like Ag was formed by nanosheet self-assembly as a SERS-active substrate and was utilized for the preparation of flower-like Ag@molecularly imprinted polymers (MIPs) as a surface-enhanced Raman scattering (SERS) sensor. Based on the combination of the molecular imprinting technique and SERS technology, the flower-like Ag@MIPs with high sensitivity and excellent selectivity were used as SERS substrates for the detection of glibenclamide. The imprinted layer could effectively protect the flower-like Ag from oxidation and thereby may improve the stability of the SERS substrate. The intensities of the characteristic peaks obtained for the flower-like Ag@MIPs were higher than that of flower-like Ag. By applying the flower-like Ag@MIPs as an efficient and ultra-sensitive SERS platform, glibenclamide was quantitatively detected in trace concentrations as low as 1 ng mL−1. Furthermore, the SERS enhancement for the flower-like Ag@MIPs was due to the synergetic effect between electromagnetic enhancement and chemical enhancement. We believe that this reliable method can open up new opportunities for practical chemosensor or biosensor applications.
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高影响因子
GREEN CHEMISTRY
·
2022
·Vol. 24
·期 22
·8840-8852
·
IF 11.034
Zongyang Liu,Yuan Tan,Jie Li,Xiuli Li,Yan Xiao,Juan Su,Xingkun Chen,Botao Qiao,Yunjie Ding
Aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a promising alternative route to produce renewable biodegradable plastics, which has stimulated intense interest in recent years. Supported gold catalysts have shown great potential for this reaction, but the selectivity and stability need to be improved. In addition, the requirement for base additives makes the process less effective and sustainable. Herein, highly active and selective Au–Ag bimetallic nanoclusters supported on MgAl-hydrotalcite (HT) were developed for HMF oxidation to FDCA under base-free reaction conditions using molecular oxygen as the oxidant. The presence of small amounts of Ag (0.034–0.065 wt%) in Au25 clusters greatly enhanced the catalytic reaction rates and selectivity for HMF tandem oxidative steps, leading to both high conversion of HMF (>97%) and high yield of FDCA (>95%). Besides, the catalyst stability was also enhanced by the addition of Ag. The characterization results suggested that the substitution of Ag atoms modified the electronic structure of Au while likely maintaining the primary geometry. Thus, a significant synergistic effect could be observed over trace Ag modified Au–Ag bimetallic nanoclusters. The present work provides new insight into the alloying effect, and helps understand highly efficient Au-based catalysts for aerobic oxidation of biomass derived molecules under base-free conditions.
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高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Linlin Sun,Xiaoshuo Liu,Xiaohan Jiang,Yibing Feng,Weijie Yang,Nan Jiang,Jigang Wang
Many optimization strategies have been applied to the construction of materials with excellent organic contaminants removal activity, whereas the interaction mechanisms of these strategies have rarely been revealed. Here, based on the analysis and evaluation of CeO 2 -decorated hierarchical tremella-like Ag/g-C 3 N 4 (Ce@15-AC) materials, the mechanism of oxidation activity enhancement is studied in depth. Finite–difference time–domain (FDTD) simulations and density functional theory (DFT) calculations reveal the mechanism of local surface plasma resonance (LSPR) effects and interfacial electric fields. The synergistic effect of the Z-scheme electrons transfer direction and Ce 4+ /Ce 3+ redox couple conversion enable Ce@15-AC to achieve the maximum redox capacity. The hierarchical structure can generate scattering and reflection of sunlight and provide a variety of channels for light transmission. Moreover, experiments and characterizations prove that Ce@15-AC material has fantastic photoelectrochemical, physical and optical properties. The removal efficiency of tetracycline (TC) by Ce@15-AC reaches 91.7% within 40 min (20 mg/L, 100 mL), and TC is almost completely degraded after 60 min. The apparent reaction rate constant (k) of Ce@15-AC is approximately 0.05974 min −1 , which is 10.71 times higher than 3DT-CN (0.00558 min −1 ). This work provides a meritorious instance in the advanced oxidation of organic contaminants application field.
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Yingxia Ma,Miaoshi Li,Tianze Li,Haijun Yang,Ruilin Zhang,Xiaofei Ye,Wenli Meng,Xiaojun Chai,Cuixia Li
Industrial wastewater containing heavy metal Ag(I) causes irreversible harm to human health through food chain, necessitating effective removal methods. According to hard-soft acids-bases (HSAB) theory, nitrogen (N) and sulfur (S) functional groups form stable chelates with Ag(I). In this study, 2-amino-5-sulfanyl-1,3,4-thiadiazole (AST) with three N and two S groups served as organic ligand, and zinc nitrate hexahydrate provided metal center, novel amorphous metal-organic framework (Zn-AST) rich in N and S groups was synthesized via a one-pot solvothermal method. Batch experiments assessed the Zn-AST adsorption properties for Ag(I) in aqueous solutions. In addition, density-functional theory, frontier orbital theory, and molecular electrostatic surface potential analyses were used to elucidate the synthesis and adsorption mechanisms. The maximum adsorption capacity of Zn-AST for Ag(I) was 2932.91 mg/g. The Zn-AST exhibited good selectivity in the presence of Cu(II), Co(II), Ni(II), and Pb(II) ions, the removal rate for Ag(I) was 98.28 %, which was far higher than the values of other ions (all less than 10 %). The main adsorption mechanisms of Ag(I) by the Zn-AST involved electrostatic interactions, the formation of Ag–S bonds, and chelation between Ag and nitrogen functional groups. This study offers a viable strategy for developing unique adsorbents for Ag(I) removal from wastewater.
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高影响因子
BIOELECTROCHEMISTRY
·
2021
·
IF 5.373
Qiying Zhu,Canguo Li,Huiqin Chang,Meng Jiang,Xiaokai Sun,Wei Jing,Haowei Huang,Di Huang,Ling Kong,Zhiwei Chen,Feng Sang,Xiuzhen Zhang
Prostate cancer is one of the most common cancers in the world, and its early detection is vital to saving the lives of patients. In this research, a novel label-free photoelectrochemical immunosensor was designed for sensitive detection of prostate specific antigen (PSA). Ag 2 S sensitized on Ag/AgBr/BiOBr heterojunction could effectively inhibit photogenic holes recombination and improve photocurrent response and sensitivity. Ascorbic acid was an effective electron donor, which can effectively eliminate photo-generated holes. The photocurrent reduced linearly with the logarithm of PSA concentration ranged from 0.001 to 50 ng·mL −1 and the limit of detection was 0.25 pg·mL −1 . The designed sensor had the advantages of wide linear range, good stability, high reproducibility, and good selectivity. This study not only provided a method for efficient and sensitive detection of PSA, but also provided valuable reference ideas for the detection of other tumor markers.
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高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-10
·
IF 5.479
Lv Hui,Zhang Xiaobo,Li Yueyun,Ren Yong,Zhang Chunyan,Wang Ping,Xu Zhen,Li Xinjin,Chen Zhiwei,Dong Yunhui
A voltammetric sandwich immunoassay is described for the biomarker cardiac troponin I (cTnI). The gold nanocube-functionalized graphene oxide (AuNC/GO) is employed as a substrate to accelerate the electron transfer and to immobilize more primary antibodies. It also employs composite materials prepared from bimetallic gold/silver core-shell nanocubes and nitrogen and sulfur co-doped reduced graphene oxide as the signal amplifier. The introduction of N and S into GO enlarges the active surface and accelerates the electron transfer rate. Such unique characteristics render the material an effective support substrate to load more Au@AgNC and to immobilize an increasing number of second antibodies via Ag-N bonds. After specific binding with cTnI, the immunosensor was incubated in a labeled cTnI secondary antibody solution. The amperometric signal change is then measured at 0.34 V (vs. SCE) using o-phenylenediamine and hydrogen peroxide as an electrochemical probe. Response is linear in the concentration range from 100 fg∙mL −1 to 250 ng∙mL −1 , and the detection limit is 33 fg∙mL −1 .
Schematic presentation of cardiac troponin I (cTnI) electrochemical immunosensor based on gold nanocube-functionalized graphene oxide (AuNC/GO) as substrate material, bimetallic gold/silver core-shell nanocubes and nitrogen and sulfur co-doped reduced graphene oxide (Au@AgNC/N, S-rGO) as signal amplifier, and hydrogen peroxide (H 2 O 2 ) and o-phenylenediamine (o-PD) as redox probe.
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高影响因子
ACS Agricultural Science & Technology
·
2022
·
IF 0
Qijia Zhang,Tongtong Wang,Guangda Xu,Na Guo,Ce Gao,Peng Song,Lixin Xia
We report a low-cost, shape-adaptable, and stable 3D porous surface enhanced Raman scattering (SERS) film–substrate, on which silver nanoparticles (Ag NPs) were loaded. The SERS substrate could not only be directly immersed in Nile blue A (NBA) solution for detection but also detect triazophos in food by wiping the analytes on solid surfaces. A broad linearity range of 0.2–1 ppb and a low limit of detection of 80 ppt were achieved for a triazophos solution. The substrate was stable and exhibited a high sensitivity after 5 weeks of storage at room temperature. In addition, the substrate has been successfully applied to the detection of practical samples of apples, cabbage, lettuce, and green onions. Thus, this simple and highly efficient SERS substrate may have great potential in pesticide-sensing applications.
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JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2020
·
IF 5.647
Yang Wang,Pengcheng Gao,Yingying Wei,Yajin Jin,Si Sun,Zhifei Wang,Yong Jiang
A facile and cost-effective preparation of silver nanoparticles decorated magnetic composite for the effective catalytic degradation of 4-nitrophenol (4-NP) and Methylene blue (MB) and Rhodamine B (RhB) was investigated. Fe 3 O 4 @Polystyrene@Ag (Fe 3 O 4 @PS@Ag) catalyst was prepared via a two-step procedure. Firstly, carboxyl groups modified magnetic microspheres (Fe 3 O 4 @PS-COOH) has been successfully synthesized by microemulsion polymerization. Then Ag ions were adsorbed and in-situ reduced on the surface of Fe 3 O 4 @PS microspheres . To estimate the catalytic activity of Fe 3 O 4 @PS@Ag catalyst, the reduction experiments of MB, RhB and 4-NP were performed in the presence of NaBH 4 . The results indicated that Fe 3 O 4 @PS@Ag catalyst has a good catalytic performance and these dyes can be reduced in a very short time, which the apparent rate coefficients are 0.0089 s −1 , 0.0187 s −1 and 0.0086 s −1 for MB, RhB and 4-NP respectively. In addition, it could be easily collected from aqueous solution by a magnet so that the catalyst could be recovered and reused after the catalytic process. The catalytic activity was still high after seven cycles. This catalytic reaction is in agreement with the pseudo-first-order kinetic equation . Furthermore, the as-prepared Fe 3 O 4 @PS@Ag catalyst outperforms other catalysts in the degradation of these organic dyes.
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高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2023
·
IF 6.9
Jiayong Zhang,Bin Yao,Zhanhui Ding,Yongfeng Li,Ding Ma,Mengge Li,Yuting Sun,Chunkai Wang,Yue Liu,Xiaofei Sun
Although trace silver (Ag) substitution for Cu in Cu 2 ZnSn(S, Se) 4 (CZTSSe) offers benefits in improving open-circuit voltage (V OC ) of CZTSSe solar cells, its further development is still hindered by the fairly low short-circuit current density (J SC ) owing to the increase of bandgap (E g ) of the absorber layer . Herein, a strategy is demonstrated to mitigate the poor J SC arising from the Ag substitution by tuning the Cu 2+ /(Cu + +Cu 2+ ) percentage in the (Cu, Ag) 2 ZnSnS 4 (CAZTS) precursor solution . Depth characterization indicates that the appropriate Cu 2+ /(Cu + +Cu 2+ ) percentage in the CAZTS precursor solution increases the photogenerated charges separation and carrier transport processes for Ag-substituted CZTSSe (CAZTSSe) solar cells. Benefiting from this strategy, the power conversion efficiency (PCE) of 9.57% is achieved when the Cu 2+ /(Cu + +Cu 2+ ) is 50 at.%. The main factor for the improvement of PCE is due to the increase in photogenerated current density (J L ) and decrease in shunt resistance (R sh ). It is demonstrated that the increase in J L results from a widening in the depletion layer width (W d ) of the p-n junction and an increase in carrier lifetime, induced by optimization of the Cu 2+ /(Cu + +Cu 2+ ) percentage. While the decrease in R sh comes from the change of reaction pathways due to the change in Cu 2+ /(Cu + +Cu 2+ ) percentage.
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高影响因子
LANGMUIR
·
2017
·
IF 3.833
Liwei Dai,Liping Song,Youju Huang,Lei Zhang,Xuefei Lu,Jiawei Zhang,Tao Chen
Due to the larger surface area and the synergistic effects between two noble metals, the bimetallic superstructures exhibit enhanced distinctive optical, catalytic, and photothermal performances and surface-enhanced Raman scattering (SERS) “hot-spot” effect, and thus have attracted great interest in various applications. Compared with the common Pd, Pt hierarchical structures coated onto Au nanoparticles (NPs), easily synthesized via fast autocatalytic surface growth arising from intrinsic properties of Pd and Pt metals, precisely controlling the hierarchical Ag growth onto Au NPs is rarely reported. In our present study, the reducing agent dopamine dithiocarbamate (DDTC) was covalently capped onto the first metal core (Au) to delicately control the growth model of the second metal (Ag). This results in heterogeneous nucleation and growth of Ag precursor on the surface of Au nanorods (NRs), and further formation of cornlike bimetallic Au/Ag core–shell superstructures, which usually cannot be achieved from traditional epitaxial growth. The thickness of the hierarchical Ag shell was finely tuned in a size range from 8 to 22 nm by simply varying the amount of the ratio between Ag ions and DDTC capped on Au NR core. The tunable Ag shell leads to anisotropic bimetallic Au/Ag core–shell superstructures, displaying two distinctive plasmonic resonances in the near-infrared region (NIR). In particular, the longitudinal surface plasmon resonance exhibits a broadly tunable range from 840 to 1277 nm. Additionally, the rich hot spots from obtained Au/Ag superstructures significantly enhance the SERS performance.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Li Liu,Yueyuan Li,Lihui Tian,Qin Wei,Wei Cao
A novel and ultrasensitive sandwich-type electrochemical immunosensor was designed for quantitative detection of prostate specific antigen (PSA). The Ag overgrowth in Pd nano-octahedrons, developed Pd-Ag heterodimers (Pd-Ag HDs), loaded on amino functionalized multiwalled carbon nanotubes (MWCNTs-NH 2 ) were employed as labels of secondary antibodies (Ab 2 ). The synergistic effect of Pd-Ag HDs exhibited high electrocatalytic activity towards the reduction of H 2 O 2 . MWCNTs-NH 2 with good dispersion , plentiful amino groups and large specific surface area , could load a large number of Pd-Ag HDs to enhance the sensitivity and amplify the signal of the immunosensor. Moreover, the electroplated gold nanoparticles (Au NPs) were employed for the immobilization of primary antibodies (Ab 1 ). Au NPs with excellent conductivity could enhance the electron transport between substrate material and electrode surface , and improve the sensitivity of immunosensor. Under optimal conditions, the electrochemical immunosensor exhibited a wide linear range of 0.1 pg/mL–30 ng/mL towards PSA, and a low detection limit of 0.03 pg/mL (S/N = 3). The proposed immunosensor exhibited good sensitivity, reproducibility and stability for the quantitative detection of PSA, which hold a great potential in clinical and diagnostic applications.
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高影响因子
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