Food Analytical Methods
·
2019
·Vol. 13
·期 3
·718-725
·
IF 2.413
Chen Yisheng,Huang Caihong,Hellmann Bernhard,Xu Xueming
This paper presented a facile and efficient HPTLC method for quantifying riboflavin fortification in rice noodle that was a staple food popular in Asian countries. After high-throughput separation on silica gel plates with methanol/ethyl acetate/triethylamine (3/7/1, v /v/v) as the mobile phase, the obtained results were analyzed by fluorescence densitometry (mercury lamp, 360 nm excitation wavelength in combination with K400 optical filter). Quantification in this way offered high linearity ( R 2 = 0.9998 within 10–80 ng/band) and precision (RSD < 5.2%), adequate detectability (LOD = 0.1 and LOQ = 0.3 mg/kg), and accuracy (spike-recovery rates within 91.4–105.1%, RSD < 8.1%). While yielding good comparison to conventional HPLC detection, the developed quantification featured superiorly high efficiency. Apart from that, the separation results were further evaluated by SERS. By jointly using sodium borohydride reduced AgNPs as the active substrate and 633 nm incident laser wavelength, the developed HPTLC-SERS detection gave clear and sensitive fingerprint-like proof which enabled unambiguous confirmation by visual inspection. Balancing well between simplicity, detectability, efficiency, and reliability, the proposed method exemplarily shown the promising applicability of HPTLC as a versatile tool in food analysis.
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ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Shaoyun Chen,Ben Liu,Xingying Zhang,Yalun Mo,Fang Chen,Hong Shi,Weihong Zhang,Chenglong Hu,Jian Chen
The high sensitivity and reproducibility are significant for the routine Surface-enhanced Raman Scattering (SERS) detection. Here, the pyramid-shape silver microstructures has been successfully synthesized using a facile electrochemical deposition method and the reaction with a two-indium tin oxides (ITO) electrode system is carried out by potentiostatic method, where only silver nitrate (AgNO 3 ) and poly (methyl methacrylate) (PMMA) nanospheres are introduced to control the reaction process. Meanwhile, PMMA nanospheres as morphology controlled reagents are used to lead Ag units to grow in the form of pyramid-shape. The prepared pyramid-shape silver microstructures possesses high SERS activity with an average enhancement factor ( EF ) of 9.1 × 10 5 , which is superior or close to some individual Ag or Au microstructures and Ag composite materials. In addition, an excellent reproducibility is achieved resulting from a relative standard deviation of 7.9%, 8.5%, 7.3%, and 8.7% measured by four Raman shifts of R6G at 612, 772, 1363, and 1650 cm −1 , respectively, which is much lower than those of the commonly used SERS substrates. Importantly, the as-prepared pyramid-shape silver microstructures have been evolved as a sensitive SERS substrate for the detection of trace amounts of rhodamine 6G (R6G) and 3-mercaptopropionic acid (3MPA) down to nanomolar and millimolar concentration with excellent recyclability. Therefore, this work offers a simple way to prepare pyramid-shape silver microstructures as an effective SERS substrate and make the SERS more practicable.
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NANO
·
2018
·
IF 1.1
Chang Liu,Qianqian Su,Li Li,Jie Sun,Jian Dong,Weiping Qian
In this work, we designed a simple substrate-immersed solvothermal route for the one-step synthesis of novel ordered SiO 2 /Ag arrays, employing SiO 2 colloidal crystals as templates and alcohol as reducing agent. The Ag nanoparticles were uniformly deposited in situ onto SiO 2 colloidal crystals, which exhibited high surface enhanced Raman spectroscopy (SERS) activity and uniform SERS intensity. It was found that ordered SiO 2 /Ag arrays could rapidly scavenge the absorbed-Nile blue A (NBA) molecules from the surfaces with the assistance of H 2 O 2 , while the SERS signals of NBA decreased sharply and almost completely disappeared within four minutes. This can be attributed to the superior catalytic activity of Ag nanoparticles. After five times of re-immersion and re-absorbing process of NBA, the substrates could still keep ∼ 74.8% SERS intensity versus the original. The high activity and durability of the as-prepared SiO 2 /Ag SERS substrate endow them as a promising candidate for trace detection.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Guihong Ding,Shi Xie,Yongmei Zhu,Ying Liu,Li Wang,Fugang Xu
An active surface-enhanced Raman scattering (SERS) substrate composed of graphene oxide (GO) wrapped gold nanoparticles (AuNPs) decorated-magnetic sphere Fe 3 O 4 (GO wrapped Fe 3 O 4 @Au hybrid) was prepared and used for aromatic dye detection. The hybrid was characterized by SEM, EDX, XRD, UV–visible spectroscopy and Raman spectroscopy. This hybrid showed high activity for SERS detection of aromatic dye due to the synergistic interaction among GO nanosheet, AuNPs and Fe 3 O 4 sphere. The dosages of AuNPs and GO were optimized to achieve a high sensitivity. The unique GO wrapped Fe 3 O 4 @Au hybrid has several advantages (such as high adsorption to target dye molecules, low noise response and high SERS enhancement ability) as SERS substrate over previously reported Fe 3 O 4 and AuNPs co-decorated GO sheet. Finally, the hybrid was successfully used for SERS detection of aromatic dye pollutant malachite green (MG) and nile blue A (NBA) even at concentration down to 1 nM and 0.1 nM, respectively. Potential of this substrate for multiplex detection of dye mixture (MG and NBA), and practical detection of MG in real sample were also evaluated. Our results suggested that the hybrid of GO wrapped Fe 3 O 4 @Au can be used as an efficient SERS platform for aromatic dye detection.
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MACROMOLECULAR RESEARCH
·
2013
·Vol. 21
·期 3
·306-310
·
IF 1.639
Zhang Wen-Yi,Xiao Xin-Ze,Lv Chao,Zhao Jia,Wang Gong,Gu Xuan,Zhang Ran,Xu Bin-Bin,Zhang Dan-Dan,Li Ai-Wu,Zhang Yong-Lai,Sun Hong-Bo
Reported here is the fabrication of photopolymer hierarchical micronanostructures through a combinative process of electrospinning and subsequent photolithography. Electrospun SU-8 (epoxy-based negative photoresist) nanofiber films have been patterned into gratings with periods of 100, 200, 300, and 400 μm, respectively. Deposition of a silver nanolayer on these interlaced nanofiber films would lead to the formation of various plasmonic nanostructures, and therefore, giving rise to abundant surface-enhanced Raman scattering (SERS) “hot spots”. In the detection of Rhodamine 6G (R6G), probing molecule, the resultant SERS substrates show both high sensitivity and good reproducibility. The SERS enhancement factor could reach as high as ∼10 8 , indicating high efficiency. The fabrication of patterned, highly efficient SERS substrates may hold a great promise for the integration of SERS substrates in various microdevices such as microfluidic chips.
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PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2014
·Vol. 17
·期 33
·21158-21163
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IF 4.198
Meng Jiang,Zhijiang Qian,Xufeng Zhou,Xing Xin,Jinghua Wu,Chao Chen,Gongjun Zhang,Gaojie Xu,Yuchuan Cheng
A structure of hexadecyl trimethyl ammonium bromide (CTAB) micelle-assisted reduced graphene oxide–Ag nanoparticle (rGO–AgNP) hybrids is designed and fabricated for SERS detection of nonpolar polycyclic aromatic hydrocarbons (PAHs), in which CTAB micelles act as the host material to capture PAH molecules. This method provides stable aqueous suspensions of functionalized graphene with an alkyl chain, since the rGO–AgNP hybrids do not need to be pre-modified by CTAB. The result shows that the CTAB-assisted rGO–AgNP substrate has excellent SERS performance toward PAHs and ideal stability under continuous laser radiation. With further optimization, the detection limits of pyrene and perylene were 10−6 M and 10−7 M, respectively. Two different PAH molecules could be detected simultaneously by their characteristic peaks.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2014
·Vol. 38
·期 8
·3395-3400
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IF 3.159
Ai-Jun Wang,Jing-Jing Lv,Dan-Ling Zhou,Xuexiang Weng,Su-Fang Qin,Jiu-Ju Feng
In this report, ultrathin worm-like Au nanowires were constructed with the assistance of L-glutamic acid as a structure-directing agent and a weak stabilizing agent. The morphology of the Au products was found to be strongly dependent on the experimental parameters such as the amount of L-glutamic acid, as well as the reaction temperature. This synthesis was a seedless process, without using any template, surfactant, or toxic organic agent. Furthermore, the as-prepared Au nanowires were applied to facilely fabricate porous Au films with controllable thickness via simple gravity settling. The Au films showed high surface-enhanced Raman scattering (SERS) enhancement, using 4-mercaptobenzoic acid as a model probe. The Au films may be promising candidates for SERS sensing. This strategy provides an environmental friendly way for the preparation of various metal nanostructures with novel morphologies and useful applications.
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RSC Advances
·
2015
·Vol. 5
·期 110
·90457-90465
·
IF 3.84
Shicai Xu,Jihua Wang,Yan Zou,Hanping Liu,Guiying Wang,Xiumei Zhang,Shouzhen Jiang,Zhen Li,Dongyan Cao,Rongxia Tang
An efficient surface enhanced Raman scattering (SERS) substrate of graphene-isolated Ag nanoparticle (G/AgNP) has been developed by using excimer laser to ablate the ordered pyrolytic graphite in high vacuum onto Ag nanoparticles. By combining the electromagnetic activity of AgNPs and unique physical/chemical properties of graphene, the G/AgNP substrates shows high performance in terms of sensitivity, signal-to-noise ratio and reproducibility. The average enhancement factor obtained from the G/AgNP substrates for rhodamine 6G probe molecules is over 108. The maximum deviations of SERS intensities from 20 positions of a same SERS substrate are in the range of 4.20% to 6.75% and from 20 different substrates in various batches are in the range of 4.43% to 7.71%, depending on different vibration modes. As a practical application of this SERS system, we detect the adenosine concentration in human serum. The detection results show a good linear correlation between SERS intensity and adenosine concentration within the range of 2 to 200 nM. This work may open up new opportunities in developing the applications of SERS in biomedical diagnostics, biological sensing and other biotechnology.
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ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Xiaoxia Wu,Liqiang Luo,Sugeun Yang,Xuehua Ma,Yonglong Li,Chen Dong,Yuchen Tian,Ling’e Zhang,Zheyu Shen,Aiguo Wu
The detection of circulating tumor cells (CTCs) in the blood of cancer patients is crucial for early cancer diagnosis, cancer prognosis, evaluation of the treatment effect of chemotherapy drugs, and choice of cancer treatment options. In this study, we propose new surface-enhanced Raman scattering (SERS) nanoparticles for the direct detection of CTCs in the blood. Under the optimized experimental conditions, our SERS nanoparticles exhibit satisfying performances for the direct detection of cancer cells in the rabbit blood. A good linear relationship is obtained between the SERS intensity and the concentration of cancer cells in the range of 5–500 cells/mL (R2 = 0.9935), which demonstrates that the SERS nanoparticles can be used for the quantitative analysis of cancer cells in the blood and the limit of detection is 5 cells/mL, which is lowest compared with the reported values. The SERS nanoparticles also have an excellent specificity for the detection of cancer cells in the rabbit blood. The above results reinforce that our SERS nanoparticles can be used for the direct detection of CTCs in the blood with excellent specificity and high sensitivity.
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APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Zhengyi Zhang,Jiajie Yu,Jingying Yang,Xiang Lv,Tianhe Wang
Porous Ag/TiO 2 composite films were prepared by spin coating of titania on normal glass slides and subsequent photochemical deposition of silver nanoparticles (AgNPs). The films were characterized by XRD and FESEM to reveal micro structural and morphological differences between films obtained under varied conditions. The SERS properties of these films were investigated using aqueous crystal violet (CV) as probe molecules. The results indicate that the content of polyethylene glycol (PEG) and photo-reduction time had significant influences on both the microstructure and SERS performance of Ag/TiO 2 films. The highest SERS sensitivity that allowed as low as 10 −10 M aqueous CV to be detected, was achieved with the PEG/(C 4 H 9 O) 4 Ti molar ratio being 0.08% and with 30 min of UV irradiation. With this film a linear relationship was established through experiment between SERS intensity and CV concentration from 10 −10 to 10 −5 M, which could be used as a calibration curve for CV concentration measurement. In addition, the film could be reused as a SERS substrate for up to four times without significantly losing SERS sensitivity if a simple regeneration was followed. It is visualized that the Ag/TiO 2 film on glass has potentials for being developed into a practical SERS substrate with high sensitivity and good reusability.
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APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Xia Yang,Yi He,Xueling Wang,Ruo Yuan
Mercuric ion (Hg 2+ ) is one toxic metal ion existed in aquatic ecosystems which would seriously damage human central nervous system and other organs. So developing an approach to sensitively detect Hg 2+ in our living environment is urgent and important. In this work, a novel surface enhancement Raman spectrum(SERS) sensor is fabricated for high selective and ultrasensitive detection of Hg 2+ in aqueous solution, based on a stable thymine-Hg 2+ -thymine (T-Hg 2+ -T) structure and the π - π interaction between single-stranded DNA (ssDNA) and single walled carbon nanotubes (SWCNTs). Herein, SWCNTs act as Raman labels to produce characteristic Raman peaks which can be a beacon to quantitative detect Hg 2+ . In the presence of Hg 2+ , the ssDNA can capture Hg 2+ forming T-Hg 2+ -T structure, which makes SWCNTs leave the hot spots of the SERS-based biosensor. With this design, the Raman intensity of SWCNTs decreased with the increasing concentration of Hg 2+ . At the same time, CoFe 2 O 4 @Ag as active SERS substrates can effectively enhance sensitivity and uniformity of the biosensor through aggregation by magnet. Under optimal conditions, this proposed biosensor can detect Hg 2+ at a range from 1 pM to 100 nM with a detection limit of 0.84 pM. With the advantages of good sensitivity, selectivity, simplicity and rapidity, the biosensor is potentially suitable for monitoring of Hg 2+ in environmental applications.
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BIOSENSORS & BIOELECTRONICS
·
2017
·
IF 7.78
Dan Li,Yadan Ma,Huazhen Duan,Wei Deng,Dawei Li
This study demonstrates a novel strategy for colorimetric/fluorescent/surface enhanced Raman scattering (SERS) triple-mode sensing of nitrite based on Griess reaction modulated gold nanorods (GNRs)-Azo-gold nanoparticles (GNPs) (GNRs-Azo-GNPs) assembly. The p -aminothiophenol (PATP)-capped GNRs (GNRs@PATP) and 1,8-diaminonaphthalene (DAP)-modified GNPs (GNPs@DAP) are first synthesized through Au–S and Au–N bonds, respectively. Upon being excited at 365 nm, the dispersion of GNRs-GNPs (GNRs@PATP and GNPs@DAP) emits cyan fluorescence. Next, the addition of nitrite into the GNRs-GNPs induces the formation of GNRs-Azo-GNPs assembly, resulting in the enhancement of color and decrease of fluorescence. Therefore, the GNRs-Azo-GNPs assembly can not only be used as a naked-eye indicator of nitrite changed from orange-yellow to purple, but also as a highly selective ‘‘fluorescence quenching’’ probe due to the fluorescence resonance energy transfer (FRET) between azo-moiety and DAP. The limit of detection (LOD) for nitrite is 0.05 μM by colorimetry and 0.01 μM by fluorescence. Meanwhile, the GNRs-Azo-GNPs assembly possesses controllable core–satellites nanostructures and enables on-field SERS detection of nitrite with the LOD of 0.8 nM. More importantly, the GNRs-GNPs sensing system can not only be used as a paper-based test strip for on-site fast screening of nitrite with a high sensitivity and selectivity, but also as a SERS substrate for reliable quantitative analysis of nitrite. This study offers a new method for on-site visual detection of nitrite in human urine and meat products, as well as provides a strategy for designing multi-mode sensing platform for various applications.
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