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Amina Rhouati, Gonca Bulbul, Usman Latif, Akhtar Hayat, Zhan-Hong Li, Jean Louis Marty
Recent years have witnessed an overwhelming integration of nanomaterials in the fabrication of biosensors. Nanomaterials have been incorporated with the objective to achieve better analytical figures of merit in terms of limit of detection, linear range, assays stability, low production cost, etc. Nanomaterials can act as immobilization support, signal amplifier, mediator and artificial enzyme label in the construction of aptasensors. We aim in this work to review the recent progress in mycotoxin analysis. This review emphasizes on the function of the different nanomaterials in aptasensors architecture...
October 28, 2017: Toxins
Pegah Hashemi, Hasan Bagheri, Abbas Afkhami, Yalda Hosseinzadeh Ardakani, Tayyebeh Madrakian
In the present research, we have developed a novel label free aptasensor based on screen printed carbon electrode (SPCE) modified with three-dimensional magnetic reduced graphene oxide(3D-MRGO)/polyaniline(PA)/gold nanoparticle(AuNP) nanocomposite for impedimetric determination of cocaine. To achieve this goal, a specific thiolated cocaine aptamer was immobilized onto the surface of synthesized nanocomposite. The signaling mechanism of the proposed aptasensor was based on increase in the [Fe(CN)6](3-/4-) charge transfer resistance (RCT) as an electrochemical probe in the presence of target analyte...
December 15, 2017: Analytica Chimica Acta
Guoli Xu, Danqun Huo, Changjun Hou, Yanan Zhao, Jing Bao, Mei Yang, Huanbao Fa
Chlorpyrifos is a commonly used organophosphorus pesticide in agriculture. However, its neurotoxicity poses a huge threat to human health. To detect trace amounts of chlorpyrifos, we herein developed a regenerative electrochemical aptasensor for the sensitive detection of chlorpyrifos. The nanocomposite consisting of copper oxide nanoflowers (CuO NFs) and carboxyl-functionalized single walled carbon nanotubes (c-SWCNTs) was prepared to improve the sensing performance for chlorpyrifos detection. Various characterization methods such as scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and cyclic voltammetry (CV) were used to demonstrate the successful fabrication of biosensor...
February 1, 2018: Talanta
Long Ma, Nana Sun, Jinyan Zhang, Chunhao Tu, Xiuqi Cao, Demin Duan, Aipo Diao, Shuli Man
We report a novel assembly of polyethyleneimine (PEI)-coated Fe3O4 nanoparticles (NPs) with single-stranded DNA (ssDNA), and the fluorescence of the dye labeled in the DNA is remarkably quenched. In the presence of a target protein, the protein-DNA aptamer mutual interaction releases the ssDNA from this assembly and hence restores the fluorescence. This feature could be adopted to develop an aptasensor for protein detection. As a proof-of-concept, for the first time, we have used this proposed sensing strategy to detect thrombin selectively and sensitively...
November 13, 2017: Nanoscale
Sunil K Arya, Pavel Zhurauski, Pawan Jolly, Marina R Batistuti, Marcelo Mulato, Pedro Estrela
We report the development of a simple and powerful capacitive aptasensor for the detection and estimation of human epidermal growth factor receptor 2 (HER2), a biomarker for breast cancer, in undiluted serum. The study involves the incorporation of interdigitated gold electrodes, which were used to prepare the electrochemical platform. A thiol terminated DNA aptamer with affinity for HER2 was used to prepare the bio-recognition layer via self-assembly on interdigitated gold surfaces. Non-specific binding was prevented by blocking free spaces on surface via starting block phosphate buffer saline-tween20 blocker...
November 8, 2017: Biosensors & Bioelectronics
Lei Shi, Xiaojiao Rong, Yan Wang, Shiming Ding, Wanying Tang
Herein, novel and versatile electrochemical aptasensors were constructed on a self-supported nanoporous gold (np-Au) microelectrode, integrating with an exonuclease III (Exo III) induced signal amplification strategy. Self-supported np-Au microelectrode with 3D bicontinuous nanoporous structures possesses tremendously large specific area, clean surface, high stability and biocompatibility, bringing about significant advantages in both molecular recognition and signal response. As paradigms, two analytes of bisphenol A (BPA) and ochratoxin A (OTA) were selected to demonstrate the superiority and versatility of designed aptasensors...
November 6, 2017: Biosensors & Bioelectronics
Qingcui Xu, Zengning Liu, Jiayun Fu, Wenping Zhao, Yemin Guo, Xia Sun, Haiyun Zhang
A sensitive and efficient ratiometric electrochemical aptasensor was designed for tetracycline (TET) detection in milk. The ratiometric electrochemical aptasensor was constructed by integrating two aptasensors termed as aptasensor 1 and aptasensor 2. The aptasensor 1 was fabricated that based on ferrocene (Fc) and gold nanoparticles (AuNPs) nanocomposite. Meanwhile, the aptasensor 2 was prepared that based on carbon nanofibers (CNFs) and AuNPs nanocomposite. TET-aptamer was immobilized effectively onto screen-printed carbon electrodes (SPCEs) surface through forming Au-S bond between AuNPs and thiol of aptamer at 5' end to construct the aptasensor 1 and aptasensor 2...
November 7, 2017: Scientific Reports
Chuanpan Guo, Fangfang Su, Yingpan Song, Bin Hu, Minghua Wang, Linghao He, Donglai Peng, Zhihong Zhang
This study reported a novel biosensor based on the nanocomposite of zirconium metal-organic framework (Zr-MOF, UiO-66) embedded with silver nanoclusters (Ag NCs) using the carcinoembryonic antigen (CEA)-targeted aptamer as template (AgNCs@Apt@UiO-66). The synthesized AgNCs@Apt@UiO-66 nanocomposite not only possesses good biocompatibility, active electrochemical performance, and strong bioaffinity, but also can be dispersed to form two-dimensional nanocomposite with nanoscale thickness. As such, the use of the AgNCs@CEA-aptamer enables AgNC@Apt@UiO-66 with sensitive and selective detection capacity of trace CEA, further concurrently being exploited as scaffold for surface plasmon resonance spectroscopy (SPR) and electrochemical biosensors...
November 16, 2017: ACS Applied Materials & Interfaces
L Madianos, G Tsekenis, E Skotadis, L Patsiouras, D Tsoukalas
A novel impedimetric biosensor was developed for the detection of the two extensively used pesticides, acetamiprid and atrazine. By employing the sputtering and e-beam lithography techniques, platinum nanoparticles (Pt NPs) were deposited in a bridge-like arrangement, in between interdigitated electrodes (IDEs). The resulting Pt NP microwires were chemically functionalized to allow the covalent immobilization of aptamers against the two target analytes onto the sensor surfaces. The biosensing platform facilitated charge transfer through the microwire-bridged IDEs, while upon analyte binding to the immobilized aptamers electron transfer was hindered, resulting in an increase of the electrochemical cell's impedance...
October 16, 2017: Biosensors & Bioelectronics
Huimei Da, Hongyan Liu, Yingning Zheng, Ruo Yuan, Yaqin Chai
We developed a novel "signal-off" photoelectrochemical (PEC) aptasensor based on an aptamer bridged DNA network structure for the sensitive detection of vascular endothelial growth factor (VEGF165), using g-C3N4 as photoactive material. The DNA network provides an excellent platform for the immobilization of methylene blue (MB), which can facilitate the electron transport through the DNA helix structure and suppress the recombination of electron-hole pairs generated by g-C3N4. In the presence of the target VEGF165, the DNA network can be destroyed adequately by the recognition between VEGF165 and the aptamer, resulting in the release of MB...
October 17, 2017: Biosensors & Bioelectronics
Xiang Zhao, Mingkun Zhang, Dongshan Wei, Yunxia Wang, Shihan Yan, Mengwan Liu, Xiang Yang, Ke Yang, Hong-Liang Cui, Weiling Fu
The aptamer and target molecule binding reaction has been widely applied for construction of aptasensors, most of which are labeled methods. In contrast, terahertz technology proves to be a label-free sensing tool for biomedical applications. We utilize terahertz absorption spectroscopy and molecular dynamics simulation to investigate the variation of binding-induced collective vibration of hydrogen bond network in a mixed solution of MUC1 peptide and anti-MUC1 aptamer. The results show that binding-induced alterations of hydrogen bond numbers could be sensitively reflected by the variation of terahertz absorption coefficients of the mixed solution in a customized fluidic chip...
October 1, 2017: Biomedical Optics Express
Biyas Posha, Sindhu R Nambiar, N Sandhyarani
We have constructed an aptamer immobilized gold atomic cluster mediated, ultrasensitive electrochemical biosensor (Apt/AuAC/Au) for LPS detection without any additional signal amplification strategy. The aptamer self-assemble onto the gold atomic clusters makes Apt/AuAC/Au an excellent platform for the LPS detection. Differential pulse voltammetry and EIS were used for the quantitative LPS detection. The Apt/AuAC/Au sensor offers an ultrasensitive and selective detection of LPS down to 7.94 × 10(-21)M level with a wide dynamic range from 0...
October 16, 2017: Biosensors & Bioelectronics
Somayeh Jamshidi Moghadam, Azadeh Azadbakh
Here, a method is introduced for construction the aptameric biosensor for biosensing detection of cytochrome C (CYC) based on chain-shape structure of aptasensor by using highly dispersed silver nanoparticles (AgNPs) on acid-oxidized carbon nanotube (CNTs) substrate. The animated capture probe (ssDNA1) and CYC-aptamer (ssDNA2) was immobilized on AgNPs/CNTs surface by covalent amide bonds formed by the carboxyl groups on the nanotubes and the amino groups on the oligonucleotides and hybridization, respectively...
October 23, 2017: Analytical Biochemistry
Yanlian Niu, Meilin Chu, Ping Xu, Shuangshuang Meng, Qian Zhou, Wenbo Zhao, Bo Zhao, Jian Shen
In this paper, novel heparin-mimicking hyperbranched polyester nanoparticles (HBPE-SO3 NPs) with abundant of sulfonated acid functional groups were synthesized, and their antithrombogenicities were further evaluated. Further, a label-free electrochemical aptamer biosensor (aptasensor) based on HBPE-SO3 NPs modified electrode was developed for thrombin (TB) detection in whole blood. Meanwhile, the anti-biofouling properties of different modified electrodes were studied by whole blood and platelet adhesion test, hemolysis assay and morphological changes of red blood cells in vitro...
October 18, 2017: Biosensors & Bioelectronics
Lei Wang, Fengchun Huang, Gaozhe Cai, Lan Yao, Huilin Zhang, Jianhan Lin
The continuous outbreaks of foodborne diseases have drawn public attentions to food safety. Early screening of foodborne pathogens is crucial to prevent and control of foodborne diseases. In this study, a novel electrochemical aptasensor was developed for rapid and sensitive detection of E. coli O157:H7 using the coaxial capillary with immune magnetic nanoparticles (MNPs) for specific separation of the target bacteria, the urease with urea for amplification of the impedance signals, and the PCB gold electrode for measurement of the impedance change...
2017: Nanotheranostics
Jue Wang, Wenbo Cheng, Fanyu Meng, Mo Yang, Yue Pan, Peng Miao
Theophylline is a popular drug for many respiratory diseases. However, certain toxic side effects may be developed and the narrow safety range raises the demand for sensitive methods to constantly monitor theophylline levels. This study presents an electrochemical approach towards theophylline detection based on the recognition by split RNA aptamers. Target induced construction of hand-in-hand RNA nanowire on the electrode surface could further absorb silver nanoparticles (Ag NPs) as electrochemical species...
October 13, 2017: Biosensors & Bioelectronics
Zak E Hughes, Tiffany R Walsh
We report on the predicted structural disruption of an adenosine-binding DNA aptamer adsorbed via non-covalent interactions on aqueous graphene. The use of surface-adsorbed biorecognition elements on device substrates is needed for integration in nano-fluidic sensing platforms. Upon analyte binding, the conformational change in the adsorbed aptamer may perturb the surface properties, which is essential for the signal generation mechanism in the sensor. However, at present, these graphene-adsorbed aptamer structure(s) are unknown, and are challenging to experimentally elucidate...
October 24, 2017: ACS Sensors
Chao Zhu, Guilan Zhang, Yafei Huang, Shuming Yang, Shuyue Ren, Zhixian Gao, Ailiang Chen
A novel dual-competitive lateral flow aptasensor (LFA) benefited from aptamer and lateral flow strips was first designed by using aflatoxin B1 (AFB1) as the model target. In this LFA assay, the target AFB1 competed with AFB1-hapten at T line for binding to Cy5-labeled AFB1 aptamer and the complementary strand competed with the target AFB1 for binding to Cy5-labeled AFB1 aptamer at C line. The ratio of their fluorescent intensities at the T line and C line (ST/SC ratio) was employed in order to increase the sensitivity for target AFB1 detection...
October 13, 2017: Journal of Hazardous Materials
Guixiang Wang, Xiaoli Su, Qingjun Xu, Guiyun Xu, Jiehua Lin, Xiliang Luo
Direct detection of targets in complex biological media with conventional biosensors is an enormous challenge due to the nonspecific adsorption and severe biofouling. In this work, a facile strategy for sensitive and low fouling detection of adenosine triphosphate (ATP) is developed through the construction of a mixed self-assembled biosensing interface, which was composed of zwitterionic peptide (antifouling material) and ATP aptamer (bio-recognition element). The peptide and aptamer (both containing thiol groups) were simultaneously self-assembled onto gold electrode surface electrodeposited with gold nanoparticles...
October 14, 2017: Biosensors & Bioelectronics
Àngela Ribes, Sara Santiago-Felipe, Andrea Bernardos, M Dolores Marcos, Teresa Pardo, Félix Sancenón, Ramón Martínez-Máñez, Elena Aznar
Aptamers have been used as recognition elements for several molecules due to their great affinity and selectivity. Additionally, mesoporous nanomaterials have demonstrated great potential in sensing applications. Based on these concepts, we report herein the use of two aptamer-capped mesoporous silica materials for the selective detection of ochratoxin A (OTA). A specific aptamer for OTA was used to block the pores of rhodamine B-loaded mesoporous silica nanoparticles. Two solids were prepared in which the aptamer capped the porous scaffolds by using a covalent or electrostatic approach...
October 2017: ChemistryOpen
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