TALANTA
·
2017
·
IF 4.162
Xin Lu,Dong-jian Jiang,Jia-xiang Yan,Zhen-e Ma,Xiu-er Luo,Tai-long Wei,Yang Xu,Qing-hua He
The rapid and widespread adoption of Bacillus thuringiensis (Bt) proteins in genetically modified (GM) crops has raised concerns about the impact of GM crops on environment and food safety. A sensitive and specific method for detecting Bt proteins in GM crops is of great significance for environment and food risk assessment. In this study, using Cry1Ab as a model Bt protein, an ultrasensitive electrochemical immunosensor for Cry1Ab protein has been developed based on phage displayed peptide. Phage displayed peptides against Cry1Ab protein were obtained from a phage displayed peptide library without animal immunization process through biopanning-elution strategy. After modification of electrode with gold nanoparticles, selected phage displayed peptide was applied to electrochemical immunosensor for Cry1Ab. Under the optimized conditions, the peptide-based immunosensor showed a dynamic range of 0.01–100 ng/mL and a limit detection of 7 pg/mL. Specific measurement of this established method was conducted by testing cross-reactivity of Cry1Ac (88% amino acid sequence homology to Cry1Ab protein), and the result showed that peptide-based immunosensor has negligible cross-reactivity with analogue. In addition, the accuracy and reproducibility of this established immunosensor was evaluated by testing the recovery of spiked samples and assay coefficients of variation, respectively. The results showed that the average recovery of corn and wheat sample was 90–120% and 86.7–120%, respectively; the intra-assay coefficient of variation was 7.4% (n = 6), and the inter-assay coefficient of variation was 6.9% (n = 6) at 1 ng/mL Cry1Ab solution. Furthermore, the novel concept of peptide-based immunosensor may provide a potential application in general method for the ultrasensitive detection of various Bt proteins.
研究领域:
生物技术
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环境科学
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食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2017
·
IF 7.78
Hongfei Gao,Luke Wen,Yuhua Wu,Zhifeng Fu,Gang Wu
The development of genetically modified (GM) insect-resistant crops has aroused great public concern about the risks on the eco-environment resulting from a release of toxic Cry proteins (such as Cry1Ab) to the soil. Therefore, it is of crucial importance to measure the Cry proteins level and the GM crops content. Here, we have tested for the first time a method that uses novel carbon nanospheres (CNPs) label-free electrochemiluminescent (ECL) immunosensor for the ultrasensitive quantification of Cry1Ab and GM crops. In this work, novel CNPs were prepared from printer toner with a very facile approach, and linked with anti-Cry1Ab antibodies to modify a golden working electrode . The immunoreaction between Cry1Ab and its antibody formed an immunocomplex on the bioreceptor region of the sensor, which inhibited electron transfer between the electrode surface and the ECL substance, leading to a decrease of ECL response. Under the optimal conditions, the fabricated label-free ECL immunosensor determined Cry1Ab down to 3.0 pg mL −1 within a linear range of 0.010−1.0 ng mL −1 , showing significant improvement of sensitivity than that of most previous reports. Meanwhile, the proposed method was successfully applied for GM rice BT63 and GM maize MON810 detections down to 0.010% and 0.020%, respectively. Due to its outstanding advantages such as high sensitivity, ideal selectivity, simple fabrication, rapid detection, and low cost, the developed method can be considered as a powerful and pioneering tool for GM crops detection. Its use can also be extended to other toxin protein sensing in foods.
研究领域:
生物技术
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环境科学
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农业科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2018
·Vol. 28
·期 4
·863-869
·
IF 1.665
Xu Xiao,Chen Hao,Cao Yuancheng,Lin Yongjun,Liu Jun’an
Here, we report the synthesis and characterization of CoFe 2 O 4 doping Ag 2 S dendrimer-modified nanoparticles (CoFe 2 O 4 -Ag 2 S DMNs) in Cry1Ab protein detection and imaging. The near-infrared Ag 2 S quantum dots were first prepared by using the thermal decomposition method, followed by modification of the water-soluble quantum dots using the method of solvent evaporation and ligand exchange, and finally the fluorescent magnetic bifunctional nanoparticles were obtained by binding with CoFe 2 O 4 . As-prepared CoFe 2 O 4 -Ag 2 S DMNs were characterized by fluorescence (FL) spectroscopy and transmission electron microscopy (TEM). Results showed that Ag 2 S DMNs could sensitively detect Cry1Ab both in vitro and in vivo. In vitro, the enhanced FL intensity as a function of the concentration is notably consistent with the Langmuir binding isotherm equation in the range of 0–200 ng/mL of Cry1Ab proteins. The detection limit of this method was found to be 0.2 ng/mL. Meanwhile, the fluorescence wavelength was extended to the second near-infrared range (NIR-II, 1.0~1.4 μm), which enables in vivo imaging. This study highlights the importance of NIR QDs doping magnetic materials as a new method to trace Bacillus thuringiensis (Bt) in insects and their potential applications in in vivo NIR tissue imaging.
研究领域:
生物化学
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分子生物学
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纳米医学
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DOI
高影响因子
ANALYTICAL BIOCHEMISTRY
·
2014
·
IF 2.305
Huami Ming,Manli Wang,Hongzong Yin
Two novel surface plasmon resonance immunosensors were fabricated for detection of the Bacillus thuringiensis Cry1Ab protein and to demonstrate their performance in analyzing Cry1Ab protein in crop samples. Sensor 2 was modified by 1,6-hexanedithiol, Au/Ag alloy nanoparticles , 3-mercaptopropionic acid, and protein A (or not [sensor 1]), with Cry1Ab monoclonal antibody . As a result, both of the immunosensors exhibited satisfactory linear responses in the Cry1Ab protein concentration ranges of 10 to 500 ng ml −1 and 8 to 1000 ng ml −1 , and the detection limits were 5.0 and 4.8 ng ml −1 , respectively. The immunosensors possessed good specificity and acceptable reproducibility. In addition, crop samples could be analyzed after a simple treatment. The transgenic crops could be easily identified from the conventional ones by the two immunosensors.
研究领域:
生物技术
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分析化学
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农业科学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2020
·
IF 0
Shuyun Meng,Ningning Zhang,Dong Liu,Xiuli Shen,Yuye Li,Fan Jia,Yang Yang,Tianyan You
The widespread introduction of Cry1Ab protein in genetically modified crops has aroused considerable concern about the risks on the environment and food safety. Herein, we reported a plasmonic enhanced photoelectrochemical (PEC) immunosensor for the precise determination of the Cry1Ab protein. Its working principle was based on the space confinement-induced surface plasmon resonance to enhance visible-light absorption of photoactive materials. The polyamidoamine (PAMAM) dendrimers were selected as the space-confined template to synthesize gold (Au) nanoparticles, that is, PAMAM–Au, which presented smaller diameter and good dispersive stability. Meanwhile, PAMAM–Au nanocomposites can exhibit significantly enhanced surface electric field intensity according to the finite-difference time-domain analysis. Further, the efficient PEC enhancement of PAMAM–Au was then validated by the highly increased photocurrent in CdSe/PAMAM–Au nanocomposites. The as-fabricated PEC immunosensor provided a wide linear range of over 4 orders of magnitude (0.01–100 ng mL–1), with the detection limit down to 3 pg mL–1 for Cry1Ab analysis. Besides, such an immunosensor was applied to analyze Cry1Ab in corn and wheat samples, and the result was in good agreement with that by the official method, enzyme-linked immunosorbent assay. Our work provides a way to fabricate high-performance sensors for the accurate detection of Cry1Ab in the environment and food products.
研究领域:
环境科学
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食品安全
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分析化学
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纳米技术
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生物化学
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产品关联
DOI
危险品化学品经营许可证（带存储）