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electrochemical sensor

Alice H Suroviec
The use of enzymatically modified electrodes for the detection of glucose or other non-electrochemically active analytes is becoming increasingly common. Direct heterogeneous electron transfer to glucose oxidase has been shown to be kinetically difficult, which is why electron transfer mediators or indirect detection is usually used for monitoring glucose with electrochemical sensors. It has been found, however, that electrodes modified with single or multi-walled carbon nanotubes (CNTs) demonstrate fast heterogeneous electron transfer kinetics as compared to that found for traditional electrodes...
2017: Methods in Molecular Biology
Nimisha Jadon, Rajeev Jain, Swati Sharma, Kshiti Singh
Voltammetric methods for screening compounds of varied interests are reviewed on the basis of the types of electrodes and analytical strategies. The scope of conventional voltammetric method has been considerably expanded in the last years due to the development of a plethora of modified electrodes, in particular, those involving nanocomposites. Voltammetric methods have distinct advantages over other existing methods regarding sensitivity, minimum detectability, applicability to biological samples without any pretreatment and time saving...
December 1, 2016: Talanta
Huichao Li, Lu Wang, Kai Sheng, Lina Zou, Baoxian Ye
The nanocomposites of titanium dioxide nanoparticles decorated poly(diallyldimethylammonium chloride)-functionalized graphene (TiO2-PDDA-Gr) were successfully synthesized via a facile and green strategy. The prepared nanocomposites were characterized by X-ray diffraction (XRD), UV-visible spectrophotometry (UV-vis), Fourier Transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). By combining the merits of the PDDA-Gr and TiO2 NPs, a highly sensitive electrochemical sensor was erected to detect esculetin based on the TiO2-PDDA-Gr nanocomposites...
December 1, 2016: Talanta
Bilal Demir, Tulay Yilmaz, Emine Guler, Z Pinar Gumus, Huseyin Akbulut, Ebru Aldemir, Hakan Coskunol, Demet Goen Colak, Ioan Cianga, Shuhei Yamada, Suna Timur, Takeshi Endo, Yusuf Yagci
Affinity-type sensors have emerged as outstanding platforms in the detection of diagnostic protein markers, nucleic acids and drugs. Thus, these novel platforms containing antibodies could be integrated into the monitoring systems for abused drugs. Herein, we established a novel detection platform for the analysis of a common illicit drug; methamphetamine (METH). Initially, a fluorescent-labeled polypeptide (EDOT-BTDA-Pala), derived from L-alanine N-carboxyanhydride (L-Ala-NCA) via ring-opening polymerization using 4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)benzo[c][1,2,5]thiadiazole-5,6-diamine (EDOT-NH2-BTDA) as initiator, was employed as a glassy carbon electrode (GCE) covering host, in order to immobilize the METH-selective antibody...
December 1, 2016: Talanta
Rosy, Rajendra N Goyal
A voltammetric sensor for the determination of 8-Hydroxydeoxyguanosine (8-OHdG); an important, sensitive and integral biomarker of oxidative stress and related pathological conditions like carcinogenesis, renal disorders, mental retardations, diabetes etc. has been fabricated. The synergistic behavior of two allotropic forms of carbon, which are electrochemically reduced graphene oxide (ErGO) and multiwalled carbon nanotubes (MWCNTs), has been exploited for the surface modification. The resulting modified surface has been characterized using Field Emission Scanning Electron Microscopy, X-ray diffraction, Electrochemical Impedance Spectroscopy and voltammetric behavior...
December 1, 2016: Talanta
Zhuang Li, Zhenzhen An, Yongyang Guo, Kangning Zhang, Xiaoling Chen, Dongxia Zhang, Zhonghua Xue, Xibin Zhou, Xiaoquan Lu
In this work, we report a novel Au-Pt bimetallic nanoparticles (Au-PtNPs) decorated on the surface of nitrogen-doped graphene (NG) functionalized with 1, 3, 6, 8-pyrene tetra sulfonic acid sodium salt (PyTS) by direct electrodeposition method. The results of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and electrochemical impendence spectrum (EIS) reveal that the Au-PtNPs were successfully anchored on the surface of NG sheets with a diameter of 20-40nm. Further, the prepared Au-PtNPs/PyTS-NG nanocomposite exhibits superior catalytic activity for the oxidation of nitrite...
December 1, 2016: Talanta
Xiangheng Niu, Jianming Pan, Fengxian Qiu, Xin Li, Yongsheng Yan, Libo Shi, Hongli Zhao, Minbo Lan
Enzyme-free electrochemical detection of glucose in alkaline media with favorable properties has been acquired by fabricating a robust and large-surface sensing platform, which is composed of anneal-shrinked Cu2O dendrites grown on porous Cu foam. On the one hand, the good compatibility of electrodeposited Cu2O architectures and Cu foam substrate, together with a post-deposition anneal at 200°C, offers a mechanically stable interface for glucose determination. On the other hand, the macropores of Cu foam that is decorated with unique Cu2O dendrites provide large active surface for electrocatalytic reaction and mass transport...
December 1, 2016: Talanta
Xuan Zhang, Yi-Chi Zhang, Jia-Wei Zhang
Chloramphenicol (CAP), as a broad-spectrum antibiotic, has been worldwide banned for using in the food producing animals due to its overuse may cause severe threats to public health. It is therefore highly desirable to develop facile, selective and sensitive biosensor for CAP detection and monitoring in drug and foodstuff samples. In this work, three-dimensional reduced graphene oxide (3DRGO) architectures were prepared through a green and template-free approach and used as active electrode materials to develop a highly selective electrochemical sensor for CAP detection...
December 1, 2016: Talanta
Ademar Wong, Tiago Almeida Silva, Fernando Campanhã Vicentini, Orlando Fatibello-Filho
New insights into the design of highly sensitive, carbon-based electrochemical sensors are presented in this work by exploring the interesting properties of graphene oxide (GO) and ionic liquids (ILs). An electrochemical sensor based on the carbon paste electrode (CPE) modified with GO and IL was developed for the sensitive detection of ofloxacin using square-wave adsorptive anodic stripping voltammetry (SWAdASV). GO sheets were obtained from the acid treatment of graphene and characterized by scanning and transmission electronic microscopy (SEM and TEM) and selected area electron diffraction (SAED), and the electrochemical behavior of the modified GO-IL/CPE was explored by electrochemical impedance spectroscopy studies...
December 1, 2016: Talanta
Qinqin Wang, Lu Wang, Kai Sheng, Lina Zou, Gaiping Li, Baoxian Ye
In this paper, a simple, low cost, highly sensitive voltammetric method for determination of tetrahydropalmatine was described, which was based on a new electrochemical sensor, poly (L-glutamic acid) functionalized electrochemical reduction graphene oxide modified glassy carbon electrode. The electrochemical behavior of tetrahydropalmatine was investigated in detail and some dynamic parameters of electrode process were calculated for the first time. Due to large surface area and good conductivity of proposed sensor, a wider linear range (3...
December 1, 2016: Talanta
R Rapini, A Cincinelli, G Marrazza
In this work, we propose an electrochemical DNA aptasensor for sensitive multidetection of acetamiprid based on a competitive format and disposable screen-printed arrays. To improve the sensitivity of the aptasensor, polyaniline film and gold nanoparticles were progressively electrodeposited on the graphite screen-printed electrode surface by cyclic voltammetry. Gold nanoparticles were then employed as platform for thiol-tethered DNA aptamer immobilization. Different acetamiprid solutions containing a fixed amount of biotinylated complementary oligonucleotide sequence by DNA aptasensor arrays were analyzed...
December 1, 2016: Talanta
Guangwen Li, Zhijun Li, Xiuhua You, Jinghua Chen, Shurong Tang
A novel label-free electrochemical biosensor for the detection of Hg(2+) based on ligase mediated creation of G-quadruplex-hemin DNAzyme has been developed. Firstly, Cp probe was immobilized on the gold electrode surface through Au-SH bond. In the presence of Hg(2+), Cp and Ap probes were partly hybridized with the LJ probe respectively through the specific T-Hg(2+)-T interaction. Then, the adjacent 3'-OH terminal of Cp will link with the 5'-PO4 terminal of Ap to form a G-rich DNA at the function of T4-ligase...
December 1, 2016: Talanta
Chellakannu Rajkumar, Balamurugan Thirumalraj, Shen-Ming Chen, His-An Chen
In this study, we demonstrate a simple preparation of graphite (GR) sheets assisted with gelatin (GLN) polypeptide composite was developed for sensitive detection of dopamine (DA) sensor. The GR/GLN composite was prepared by GR powder in GLN solution (5mg/mL) via sonication process. The prepared GR/GLN composite displays well dispersion ability in biopolymer matrix and characterized via scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS) studies...
October 14, 2016: Journal of Colloid and Interface Science
Houcem Maaoui, Florina Teodoresu, Qian Wang, Guo-Hui Pan, Ahmed Addad, Radhouane Chtourou, Sabine Szunerits, Rabah Boukherroub
Perturbations in glucose homeostasis is critical for human health, as hyperglycemia (defining diabetes) leads to premature death caused by macrovascular and microvascular complications. However, the simple and accurate detection of glucose in the blood at low cost remains a challenging task, although it is of great importance for the diagnosis and therapy of diabetic patients. In this work, carbon quantum dots decorated with copper oxide nanostructures (CQDs/Cu₂O) are prepared by a simple hydrothermal approach, and their potential for electrochemical non-enzymatic glucose sensing is evaluated...
October 18, 2016: Sensors
Fan Zhang, Yue Sun, Demei Tian, Weon Sup Shin, Jong Seung Kim, Haibing Li
Host-guest recognition plays an important role in biological analysis and biosensing. Accordingly, great efforts have been devoted to the development of sensors using versatile 3D surface materials. These functionalized nanomaterials possess the advantages of high selectivity and visual signals, enabling the selective detection of ions, amino acids, proteins, and other biological molecules. Therefore, in this feature article, we present some significant and representative examples of molecular recognition on calixarene functionalized 3D surface nanomaterials...
October 20, 2016: Chemical Communications: Chem Comm
Zhenning Yu, Lei Zou, Yanli Chen, Jianzhuang Jiang
A facile approach was developed for preparing the multilayer hybrid films of mixed (phthalocyaninato)(porphyrinato) europium (III) triple-decker compound (Pc)Eu(Pc)Eu[trans-T(COOCH3)2PP] (1) and graphene oxide (GO) using the solution-processing QLS method. Combination in the nature of relatively high conductivity and great surface area for GO with the electroactive and semiconductive triple-decker compound in ITO electrode renders the hybrid film excellent sensing property for H2O2, due to the optimized triple-decker molecular packing in the uniform-sized nanoparticles (ca...
October 19, 2016: ACS Applied Materials & Interfaces
Yichuan Hu, Bo Liang, Lu Fang, Guanglong Ma, Guang Yang, Qin Zhu, Shengfu Chen, Xuesong Ye
In this work, a versatile fabrication method of coating enzyme-based biosensors with ultra-thin antifouling zwitterionic polymer films to meet the challenge of the long-time stability of sensors in vivo was developed. Electrochemically mediated atom transfer radical polymerization (eATRP) was applied to polymerize zwitterionic sulfobetaine methacrylate (SBMA) monomers on the rough enzyme-absorbed electrode surfaces, meanwhile a refined overall bromination was developed to improve the coverage of polymers on the biosensor surfaces, and maintain the enzyme activity simultaneously for the first time...
October 18, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Rachelle M Duvall, Russell W Long, Melinda R Beaver, Keith G Kronmiller, Michael L Wheeler, James J Szykman
This study reports on the performance of electrochemical-based low-cost sensors and their use in a community application. CairClip sensors were collocated with federal reference and equivalent methods and operated in a network of sites by citizen scientists (community members) in Houston, Texas and Denver, Colorado, under the umbrella of the NASA-led DISCOVER-AQ Earth Venture Mission. Measurements were focused on ozone (O₃) and nitrogen dioxide (NO₂). The performance evaluation showed that the CairClip O₃/NO₂ sensor provided a consistent measurement response to that of reference monitors (r² = 0...
October 13, 2016: Sensors
Atanu Jana, Masatoshi Ishida, Jung Su Park, Steffen Bähring, Jan O Jeppesen, Jonathan L Sessler
After the epochal discovery of the "organic metal", namely, tetrathiafulvalene (TTF)-7,7,8,8-tetracyano-p-quinodimethane (TCNQ) dyad in 1973, scientists have made efforts to derivatize TTF for constructing various supramolecular architectures to control the charge-transfer processes by adjusting the donor-acceptor strength of the dyads for numerous applications. The interesting inherent electronic donor properties of TTFs control the overall electrochemical properties of the supramolecular structures, leading to the construction of highly efficient optoelectronic materials, photovoltaic solar cells, organic field-effect transistors, and optical sensors...
October 18, 2016: Chemical Reviews
A Fagan-Murphy, L Hachoumi, M S Yeoman, B A Patel
Reactive oxygen and nitrogen species (ROS/RNS) have been widely implicated in the ageing process and various approaches exist for monitoring these species in biological tissues. These approaches at present are limited to monitoring either a single pro-oxidant species or total pro-oxidant levels and therefore provide limited insight into the range of pro-oxidant species and their relative proportions in the ageing process. We have utilised a sensor that allows us to simultaneously monitor hydrogen peroxide, peroxynitrite, nitric oxide and nitrite...
October 14, 2016: Mechanisms of Ageing and Development
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