FOOD CHEMISTRY
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2023
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IF 8.8
Zhiyang Chen,Yue Sun,Jiyong Shi,Wen Zhang,Xinai Zhang,Xiaowei Hang,Zhihua Li,Xiaobo Zou
The goal of food safety supervision is to directly identify the pesticide residues on the surface of fruits and vegetables. This study proposed to develop a facile, non-destructive, and sensitive method based on surface-enhanced Raman scattering (SERS) to detect non-systemic pesticides on the surface of fruits and vegetables. The composite material was prepared by loading CTAB guided Au@Ag NRs with positive charge onto filter paper which was modified with PDADMAC(+) and PSS(−) using electrostatic adsorption. Au@Ag NRs with bimetallic synergies were effectively adsorbed in the fiber grid to generate 3D SERS hotspots within a few microns of depth. The results showed that the 3D composite flexible substrate had a high SERS activity, great repeatability, and sensitivity when the method was utilized to detect 4-MBA, methyl-parathion, thiram and chlorpyrifos. Three kinds of non-systemic pesticides on the peel could be detected directly and quickly owing to the arbitrary bending of the substrate, demonstrating the efficiency of the SERS “paste-reading” method. The acquired findings demonstrated that PDADMAC/PSS/Au@Ag NRs composite filter paper had the potential to provide rapid feedback for in- situ analysis of pesticide residues on the surface of fruit and vegetable.
研究领域:
食品安全
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Nano
·
2015
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IF 12.881
Leicong Zhang,Pengli Zhu,Fengrui Zhou,Wenjin Zeng,Haibo Su,Gang Li,Jihua Gao,Rong Sun,Ching-ping Wong
In this study, a flexible asymmetrical all-solid-state supercapacitor with high electrochemical performance was fabricated with Ni/MnO2—filter paper (FP) as the positive electrode and Ni/active carbon (AC)—filter paper as negative electrode, separated with poly(vinyl alcohol) (PVA)–Na2SO4 electrolyte. A simple procedure, such as electroless plating, was introduced to prepare the Ni/MnO2–FP electrode on the conventional laboratory FP, combined with the subsequent step of electrodeposition. Electrochemical results show that the as-prepared electrodes display outstanding areal specific capacitance (1900 mF/cm2 at 5 mV/s) and excellent cycling performance (85.1% retention after 1000 cycles at 20 mA/cm2). Such a flexible supercapacitor assembled asymmetrically in the solid state exhibits a large volume energy density (0.78 mWh/cm3) and superior flexibility under different bending conditions. It has been demonstrated that the supercapacitors could be used as a power source to drive a 3 V light-emitting diode indicator. This study may provide an available method for designing and fabricating flexible supercapacitors with high performance in the application of wearable and portable electronics based on easily available materials.
研究领域:
材料科学
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能源存储技术
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2016
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IF 4.758
Chong Wang,Bingxin Liu,Xincun Dou
The strongly enhanced electromagnetic “hotspots” from the edges and tips of nanoplates are highly preferred to significantly promote the surface enhanced Raman scattering (SERS) activity. Here, Ag nanotriangles with a sharp edge of 20 nm were prepared by the reduction of AgNO 3 using N,N-Dimethylformamide (DMF) with the assistance of Polyvinyl pyrrolidone (PVP). By loading of Ag nanotriangles onto the filter paper, a flexible SERS substrate with good activity and reproducibility was obtained and the ultratrace detection of p -aminothiophenol (pATP) with a concentration as low as 10 −8 M was achieved. The sharp edges and tips boosted SERS activity was proved by the finite element method modeling of the plasmonic properties of Ag nanotriangles with different edge thicknesses (10 − 80 nm), Ag nanosheets with different tip acutances (squares and hexagons) together with Ag nanorods, nanocubes and nanospheres. The experimental and theoretical results confirmed that the interspacing created by filter paper plays an important role in enhancing the overall SERS activity. Furthermore, it is shown that the present silver nanotriangles-loaded filter paper SERS substrate can be employed to sensitive and selective detecting ultratrace military explosives picric acid (PA) of 10 −6 M.
研究领域:
材料科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2020
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IF 3.232
Jie Xie,Liangyu Li,Imran Mahmood Khan,Zhouping Wang,Xiaoyuan Ma
Herein, we reported a simple, flexible and sensitive surface-enhanced Raman scattering (SERS) substrate to detect methyl parathion residues in real life. The substrate was fabricated by filter paper and gold nanoparticles (Au NPs) with excellent reproducibility and stability. First, Au NPs were synthesized by the seed mediated growth method and assembled to the filter paper through immersion. The Raman probe molecule 4-MBA was used to evaluate performance of the substrate for an optimized signal using a portable Raman spectrometer coupled with 785 nm laser. Then, the paper-based substrate was applied to detect methyl parathion standard solution whose detection limit was down to 0.011 μg/cm 2 , and the linear range was between 0.018 μg/cm 2 and 0.354 μg/cm 2 . Afterwards, actual sample (apple) spiked with methyl parathion was taken to verify the practicality of the substrate by a simple way of “press–peel off”. The recovery rate was ranged from 94.09% to 98.72%, indicating that this method is reliable in actual sample detection without complicated pretreatment steps. This work demonstrates that the flexible paper-based substrate combined with portable Raman instruments can be potentially applied to on-site detection of hazardous substances in the field of food safety.
研究领域:
食品安全
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）