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Yining Hou, Jifeng Liu, Min Hong, Xia Li, Yanhua Ma, Qiaoli Yue, Chen-Zhong Li
The design of molecular nanodevices attracted great interest in these years. Herein, a reusable, sensitive and specific aptasensor was constructed based on an extension-contraction movement of DNA interconversion for the application of human thrombin detection. The present biosensor was based on resonance light scattering (RLS) using magnetic nanoparticles (MNPs) as the RLS probe. MNPs coated with streptavidin can combine with biotin labeled thrombin aptamers. The combined nanoparticles composite is monodispersed in aqueous medium...
February 20, 2017: Biosensors & Bioelectronics
Kateryna Muzyka, Muhammad Saqib, Zhongyuan Liu, Wei Zhang, Guobao Xu
The importance of developing new diagnostic and detection technologies for the growing number of sensing challenges is rising each year. Here, we present a comprehensive and concise review on electrochemiluminescent (ECL) aptasensors by putting special emphasis on its characteristic features, advances, challenges, and applications of ECL based aptasensors. ECL is an ideal tool for constructing such sensors because of its inherent characteristics and can be easily integrated into aptamer based sensing platforms...
January 7, 2017: Biosensors & Bioelectronics
Yan Wu, Fubing Xiao, Zhaoyang Wu, Ruqin Yu
A novel aptasensor platform has been developed for quantitative detection of adenosine triphosphate (ATP) based on a ratiometric surface-enhanced Raman scattering (SERS) strategy. The thiolated 3'-Rox-labeled complementary DNA (cDNA) is first immobilized on the gold nanoparticle (AuNP) surface and then hybridizes with the 3'-Cy5-labeled ATP-binding aptamer probe (Cy5-aptamer) to form a rigid double-stranded DNA (dsDNA), in which the Cy5 and Rox Raman labels are used to produce the ratiometric Raman signals...
February 22, 2017: Analytical Chemistry
Lanshuang Hu, Shengqiang Hu, Linyan Guo, Congcong Shen, Minghui Yang, Avraham Rasooly
In addition to its primary function as a genetic material, deoxyribonucleic acid (DNA) is also a potential biologic energy source for molecular electronics. For the first time, we demonstrate that DNA can generate a redox electric current. As an example of this new functionality, DNA generated redox current was used for electrochemical detection of human epidermal growth factor receptor 2 (HER2), a clinically important breast cancer biomarker. To induce redox current, the phosphate of the single stranded DNA aptamer backbone was reacted with molybdate to form redox molybdophosphate precipitate and generate an electrochemical current of ∼16...
February 21, 2017: Analytical Chemistry
Huanhuan Li, Quansheng Chen, Md Mehedi Hassan, Xiaoxing Chen, Qin Ouyang, Zhiming Guo, Jiewen Zhao
Surface-enhanced Raman scattering (SERS) biosensors have promising potential in the field of antibiotics detection because of their ultrahigh detection sensitivity. This paper reports a rapid and sensitive SERS-based magnetic nanospheres-targeting strategy for sensing tetracycline (TTC) using aptamer-conjugated magnetite colloid nanocrystal clusters (MCNCs)-polymethacrylic acid (PMAA) magnetic nanospheres (MNs) as the recognition and the Au/PATP/SiO2 (APS) as the labels. Initially, MNs were fabricated and conjugated with the aptamers through condensation reaction...
February 7, 2017: Biosensors & Bioelectronics
Seyed Mohammad Taghdisi, Noor Mohammad Danesh, Mohammad Ramezani, Narjes Ghows, Seyed Ali Mousavi Shaegh, Khalil Abnous
To assure water safety and protect human health, precise and simple analytical approaches are highly desired to determine low concentrations of microcystin-leucine-arginine (MC-LR), a toxin, in both water and serum samples. Herein, a simple, rapid and accurate aptamer-based fluorescent sensor was used for selective recognition of MC-LR, based on single-walled carbon nanotubes (SWNTs) as immobilizers, dapoxyl as a fluorescent dye, DAP-10 as a specific aptamer for dapoxyl and unmodified MC-LR aptamer (Apt) as a sensing ligand...
May 1, 2017: Talanta
Panpan Gai, Chengcheng Gu, Ting Hou, Feng Li
Herein, we reported a novel ultrasensitive one-compartment enzyme biofuel cells (EBFCs)-based self-powered aptasensing platform for antibiotic residue detection. By taking full advantage of the unique features of both EBFCs-based self-powered sensors and aptamers, the as-proposed aptasensing platform has the merits of simple instrumentation, anti-interference ability, high selectivity, and low cost. In this study, DNA bioconjugate, i.e., SiO2@gold nanoparticles-complementary strand of aptamer (SiO2@AuNPs-csDNA), was elaborately designed and played a key role in blocking the mass transport of glucose to the bioanode...
February 7, 2017: Analytical Chemistry
Song Wang, Yajun Zhang, Guangsheng Pang, Yingwei Zhang, Shaojun Guo
The design of graphene quantum dots (GQDs)-aptamer bioconjugates as the new sensing platform is very important for developing high-sensitivity fluorescent biosensors; however, achieving new bioconjugates is still a great challenge. Herein, we report the development of a new high-sensitivity fluorescent aptasensor for the detection of ochratoxin A (OTA) based on tuning aggregation/disaggregation behavior of GQDs by structure-switching aptamers. The fluorescence sensing process for OTA detection involved two key steps: (1) cDNA-aptamer (cDNA, complementary to part of the OTA aptamer) hybridization induced the aggregation of GQD (fluorescence quenching) after cDNA was added into the GQDs-aptamer bioconjugate solution, and (2) the target of OTA triggered disaggregation of GQD aggregates (fluorescence recovery)...
February 7, 2017: Analytical Chemistry
Rasoul Pourtaghavi Talemi, Seyed Mehdi Mousavi, Hossein Afruzi
For the first time, gold nanostars (GNS) were applied for electrostatic and covalent immobilizing a thiol modified Dopamine aptamer on the pencil graphite electrode and signal amplification. Dopamine aptamer was immobilized on the gold nanostars through electrostatic interaction between negatively charged phosphate groups of aptamer and positively charged gold nanostars and AuS well known covalent interaction. In the presence of Dopamine in the test solution, the charge transfer resistance (RCT) on the electrode surface increased with the increase of the Dopamine concentration due to specific interaction between Dopamine aptamer and Dopamine molecules, which made a barrier for electrons and inhibited the electron-transfer...
April 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Yibo Ma, Junsong Liu, Hongdong Li
In this study, we designed and fabricated an electrochemical impedance aptasensor based on Au nanoparticles (Au-NPs) coated boron-doped diamond (BDD) modified with aptamers, and 6-mercapto-1-hexanol (MCH) for the detection of bisphenol A (BPA). The constructed BPA aptasensor exhibits good linearity from 1.0×10(-14) to 1.0×10(-9)molL(-1). The detection limitation of 7.2×10(-15)molL(-1) was achieved, which can be attributed to the synergistic effect of combining BDD with Au-NPs, aptamers, and MCH. The examine results of BPA traces in Tris-HCl buffer and in milk, UV spectra of aptamer/BPA and interference test revealed that the novel aptasensors are of high sensitivity, specificity, stability and repeatability, which could be promising in practical applications...
January 21, 2017: Biosensors & Bioelectronics
Yaokun Xia, Mengmeng Liu, Liangliang Wang, An Yan, Wenhui He, Mei Chen, Jianming Lan, Jiaoxing Xu, Lunhui Guan, Jinghua Chen
Recently, many studies have shown the potential use of circulating exosomes as novel biomarkers for monitoring and predicting a number of complex diseases, including cancer. However, reliable and cost-effective detection of exosomes in routine clinical settings, still remain a difficult task, mainly due to the lack of adequately easy and fast assay platforms. Therefore, we demonstrate here the development of a visible and simple method for the detection of exosomes by integrating single-walled carbon nanotubes that being excellent water solubility (s-SWCNTs) and aptamer...
January 28, 2017: Biosensors & Bioelectronics
Liling Hao, Huajie Gu, Nuo Duan, Shijia Wu, Xiaoyuan Ma, Yu Xia, Zui Tao, Zhouping Wang
A chemiluminescence resonance energy transfer aptasensor was fabricated for the detection of Staphylococcus aureus (S. aureus) with Co(2+) enhanced N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functional flowerlike gold nanoparticles (Co(2+)/ABEI-AuNFs) as donor and WS2 nanosheet as acceptor. In the presence of S. aureus, rolling circle amplification (RCA) can be started. Partially complementary sequence of RCA product functional ABEI-AuNFs (cDNA-ABEI-AuNFs) were then annealed to multiple sites of the RCA product to form duplex complex...
March 22, 2017: Analytica Chimica Acta
Hunho Jo, Jin Her, Heehyun Lee, Yoon-Bo Shim, Changill Ban
In this study, we developed a sandwich aptamer-based screen-printed carbon electrode (SPCE) using chronoamperometry for the detection of cardiac troponin I (cTnI), one of the promising biomarkers for acute myocardial infarction (AMI). Disposable three-electrode SPCEs were manufactured using a screen printer, and various modifications such as electrodeposition of gold nanoparticles and electropolymerization of conductive polymers were performed. From the bare electrode to the aptamer-immobilized SPCE, all processes were monitored and analyzed via various techniques such as cyclic voltammetry, electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy...
April 1, 2017: Talanta
Rupesh K Mishra, Akhtar Hayat, Geetesh K Mishra, Gaëlle Catanante, Vinay Sharma, Jean-Louis Marty
Lysozyme (Lys) commonly presents in wines and are known to cause toxicological impact on human health. The need of highly sensitive and reliable detection methods are evident in such matrix. In this work, we developed a competitive aptamer based assay for detection of Lys by employing carboxylated magnetic beads as a support to immobilize the target molecule Lys. The used aptamer sequence was biotinylated which further binds with Streptavidin-Alkaline phosphatase (Stp-ALP) in the micro wells. Colorimetric tests were performed in order to optimize different experimental parameters...
April 1, 2017: Talanta
Fanwei Meng, Xiaoyuan Ma, Nuo Duan, Shijia Wu, Yu Xia, Zhouping Wang, Baocai Xu
This paper investigated a new detection method of oxytetracycline (OTC) in aquatic products with ultrasensitive detection limit. The method was constructed on the basis of raman hot spot between gold nanoparticles (AuNPs) (13nm and 80nm diameter respectively) linked by an DNA sequence. The DNA sequence combined with the OTC aptamer including its complementary sequence as well as a stem-loop structure. The raman signal molecule (4-MBA) was modified at the surface of 13nm AuNPs. After the exposure of OTC, the aptamer sequence was preferentially combined with OTC and partially dehybridized with its complementary sequence which led the 13nm AuNPs to get more closer to the 80nm AuNPs...
April 1, 2017: Talanta
Zhe-Han Yang, Ying Zhuo, Ruo Yuan, Ya-Qin Chai
Herein, a novel electrochemical impedimetric biosensor for the heparanase (HPA) assay was developed based on target protein-induced DNA hydrogel formation, followed by pH-stimulation of the hydrogel density to increase the signal amplification. The method involved the synthesis of two different copolymer chains, consisting of two cooperatively functioning cross-linking elements, where one element was associated with the HPA-response and the other one with the pH-response. Initially, single-strand DNA as a capture probe was modified on the electrode surface...
February 2, 2017: Nanoscale
Jianmin Zhao, Ting Zheng, Jiaxi Gao, Shijing Guo, Xingxing Zhou, Wenju Xu
In this work, a simple and sensitive electrochemical aptasensor for protein (thrombin - TB used as the model) was developed by using cubic Cu2O nanocages (Cu2O-NCs) loaded with Au nanoparticles (AuNPs@Cu2O-NCs) as non-enzymatic electrocatalysts and robust redox probes. Through the specific sandwich-type reaction between TB and TB aptamers (TBA), the formed AuNPs@Cu2O-NCs bound with NH2-TBA were captured onto the electrode surface modified with SH-TBA. Based on the inherent redox activity of AuNPs@Cu2O-NCs with cubic nanostructures, a detectable electrochemical signal was generated which was dependent on the analyte concentration...
January 31, 2017: Analyst
Xuan Ni, Bing Xia, Lumei Wang, Jing Ye, Gaoshang Du, Haiwei Feng, Xiaotong Zhou, Tong Zhang, Wenhao Wang
In this paper, we developed a fluorescent aptasensor for 17β-estradiol (E2) determination in aqueous solution using label-free E2-specific aptamer, gold nanoparticles (AuNPs) and Rhodamine B (RhoB) as sensing probe, fluorescent quencher and fluorescent indicator respectively. In the absence of E2, AuNPs were wrapped by E2 aptamer and maintained dispersed in NaCl solution basically. These dispersed AuNPs could effectively impair the originally high fluorescence of RhoB. Contrarily, in the presence of E2, E2 aptamer could specifically combine with E2 to form E2-aptamer complex, so the AuNPs were released by E2 aptamer and aggregated under the influence of NaCl...
January 27, 2017: Analytical Biochemistry
Xiaojiao Du, Liming Dai, Ding Jiang, Henan Li, Nan Hao, Tianyan You, Hanping Mao, Kun Wang
It remains a vital task to establish ultrasensitive sensing interfaces for detection of target analytes to meet the demands of modern analysis. Herein, a highly sensitive turn-on photoelectrochemical (PEC) platform for trace 17β-estradiol (E2) assay was developed based on Au nanrods (AuNRs) with surface plasmon resonance (SPR) properties induced signal amplification. Specifically, a ternary hybrid was prepared by integrating hematite (α-Fe2O3) nanocrystals and N-doped graphene (NG) with AuNRs, which further served as highly efficient photoactive species...
May 15, 2017: Biosensors & Bioelectronics
Ayemeh Bagheri Hashkavayi, Jahan Bakhsh Raoof
The present work describes a label free electrochemical aptasensor for selective detection of epirubicin. In this project, 5'-thiole terminated aptamer was self-assembled on carbon screen printed electrode, which modified with electrodeposited gold nanoparticles on magnetic double-charged diazoniabicyclo [2.2.2] octane dichloride silica hybrid (Fe3O4@SiO2/DABCO) by Au-S bond. The interactions of epirubicin with aptamer on the AuNPs/Fe3O4@SiO2/DABCO/SPE have been studied by cyclic voltammetry, linear sweep voltammetry and electrochemical impedance spectroscopy...
May 15, 2017: Biosensors & Bioelectronics
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