TALANTA
·
2018
·
IF 4.244
Sobia Niazi,Xiaole Wang,Imran Pasha,Imran Mahmood Khan,Sen Zhao,Muhammad Shoaib,Shijia Wu,Zhouping Wang
Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by fungi on stored grains. The earlier detection methods used for ZEN rely on expensive equipment, time-consuming sample preparation and temperature sensitive antibodies. The current work, proposed a novel strategy based on ZEN aptamer labeled with amine-functionalized magnetic nanoparticle (MNPs) as a capture probe and time-resolved fluorescence (TRFL) nanoparticles labeled with complementary DNA (cDNA) as a signal probe. Under the optimized conditions, TRFL intensity at 544 nm was used to measure ZEN (R 2 = 0.9920) in the range of 0.001–10 ng mL −1 and limits of detection (LOD) for proposed method was 0.21 pg mL −1 . The specificity of bioassay was also determined by using other mycotoxins (OTA, AFB 2 , DON and Patulin) and results showed that the aptamer are specific to recognize only ZEN. The analytical applications of the present bioassay in maize and wheat samples were also examined and results were compared with existing methods. Based on these findings, it is suggested to use current rapid and simple bioassay for the determination of ZEN in food and agricultural products.
研究领域:
食品科学
·
分析化学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 10
·4021-4027
·
IF 4.58
Wang Xiaole,Niazi Sobia,Yukun Huang,Sun Weijia,Wu Shijia,Duan Nuo,Hun Xu,Wang Zhouping
The authors describe an aptasensor based on time-resolved fluorescence resonance energy transfer (TR-FRET) for the identification of Salmonella typhimurium ( S. typhimurium ). Aptamer-functionalized nanoparticles (NPs) is used as the energy donor, and a complementary oligonucleotide (cDNA) labeled with carboxyfluorescein (FAM) acts as the acceptor. The detection scheme is based on the hybridization between aptamer and cDNA, upon which photonic energy is transferred from NPs to FAM unless aptamer interacts with S. typhimurium . Due to the highly specific recognition ability of aptamer and the strong fluorescence intensity of NPs, the method is highly sensitive and selective for S. typhimurium . Under the optimal conditions, at excitation wavelength of 273 nm, a delay time of 100 μs and a gating time of 1 ms, the integrated time-resolved fluorescence intensity ratio (FAM 520 /Tb 489 ) is linear in the 100 to 10 6 cfu·mL −1 range, and the limit of detection is as low as 25 cfu·mL −1 . The assay was applied to the analysis of eggs and chicken meat for S. typhimurium , and the results were consistent with those of a plate-counting method.
Schematic of a homogeneous time-resolved FRET assay for the determination of Salmonella typhimurium by FRET between NaYF 4 :Ce/Tb nanoparticle-tagged aptamer and FAM-cDNA, with a good linearity and the limit of detection of 25 cfu mL −1 .
研究领域:
微生物学
·
纳米技术
·
食品安全
·
生物技术
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产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 7
·1453-1465
·
IF 3.286
Niazi Sobia,Khan Imran Mahmood,Yan Lv,Khan Muhammad Issa,Mohsin Ali,Duan Nuo,Wu Shijia,Wang Zhouping
A rapid and highly sensitive time-resolved fluorescence (TRF)-based aptasensor for simultaneous recognition of mycotoxins ochratoxin A (OTA) and fumonisin B 1 (FB 1 ) was developed using multi-color, Ln 3+ -doped time-resolved fluorescence nanoparticles (TRF-NPs) (NaYF 4 : Ce, Tb and NH 2 -Eu/DPA@SiO 2 NPs) coupled with complementary strand DNA (cDNA) as luminescence probe and aptamers-conjugated amine-functionalized Fe 3 O 4 magnetic nanoparticles (MNPs) act as a capture probe. Under the optimized conditions, the time-resolved fluorescence intensities at 544 and 618 nm corresponded with Tb 3+ and Eu 3+ , respectively, were used to measure FB 1 ( Y = 19,177.1 + (− 12,054.4) x , R 2 = 0.9917) and OTA ( Y = 4138.8 + (− 11,182.6) x , R 2 = 0.9924), respectively. The limits of detection (LODs) for FB 1 and OTA were 0.019 pg mL −1 and 0.015 pg mL −1 , respectively, which were much lower than previously described methods for simultaneous recognition of mycotoxins OTA and FB 1 while detection range varied from 0.0001–0.5 ng mL −1 . This aptasensor was effectively applied to quantity FB 1 and OTA in maize samples and results were compared with ELISA method. This is the first reported time-resolved fluorescence (TRF)-based aptasensor to detect two agriculturally important toxins in the maize. The developed aptasensor has potential to be used for detection of toxins in food safety fields.
Graphical abstract
研究领域:
食品安全
·
分析化学
·
纳米技术
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2018
·Vol. 8
·期 12
·1023
·
IF 3.504
Dandan Ju,Feng Song,Adnan Khan,Feifei Song,Aihua Zhou,Xiaoli Gao,Huimin Hu,Xu Sang,Victor Zadkov
The dual-mode emission and multicolor outputs in the time domain from core-shell microcrystals are presented. The core-shell microcrystals, with NaYF4:Yb/Er as the core and NaYF4:Ce/Tb/Eu as the shell, were successfully fabricated by employing the hydrothermal method, which confines the activator ions into a separate region and minimizes the effect of surface quenching. The material is capable of both upconversion and downshifting emission, and their multicolor outputs in response to 980 nm near-infrared (NIR) excitation laser and 252 nm, and 395 nm ultraviolet (UV) excitation light have been investigated. Furthermore, the tunable color emissions by controlling the Tb3+-Eu3+ratio in shells and the energy transfer of Ce3+→Tb3+→Eu3+were discussed in details. In addition, color tuning of core-shell-structured microrods from green to red region in the time domain could be obtained by setting suitable delay time. Due to downshifting multicolor outputs (time-resolved and pump-wavelength-induced downshifting) coupled with the upconversion mode, the core-shell microrods can be potentially applied to displays and high-level security.Keywords:NaYF4:Yb/Er@NaYF4:Ce/Tb/Eu microrods;dual-mode emission;time-resolved emission spectra;multicolor emission
研究领域:
材料科学
·
光学
✓ 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）