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Biosensors & Bioelectronics

Rashida Akter, Bongjin Jeong, Yong-Mi Lee, Jong-Soon Choi, Md Aminur Rahman
A novel highly sensitive dendrimer coupled impedimetric immunosensor was developed for the label-free and reagent-free detection of cardiac troponin I (TnI) in serum samples. The immunosensor probe was fabricated by covalently attaching carboxylic acid-functionalized third generation (G3) poly (amidoamine) (PAMAM) dendrimer (Den) on the 3, 3', 5, 5'-tetramethyl benzidine (TMB) modified 6-mercaptohexanoic acid (MHA) self-assembled monolayer (SAM) on a gold (Au) electrode. Monoclonal anti-TnI antibody was then covalently immobilized on the Den and TMB attached MHA SAM modified surface...
January 12, 2017: Biosensors & Bioelectronics
Xia Li, Xiaowen Xu, Juan Song, Qingwang Xue, Chenzhong Li, Wei Jiang
T4 polynucleotide kinase (PNK) plays critical roles in regulating DNA phosphorylation modes during the repair of DNA lesions. The aberrant activity of T4 PNK has been proven to be associated with a variety of human pathologies. Sensitive detection of T4 PNK activity is critical to both clinical diagnosis and therapeutics. Herein, a background-eliminated fluorescence assay for sensitive detection of T4 PNK activity has been developed by multifunctional magnetic probes and polymerization nicking reactions mediated hyperbranched rolling circle amplification (HRCA)...
January 12, 2017: Biosensors & Bioelectronics
Xin Xin, Nianbing Zhong, Qiang Liao, Yanyan Cen, Ruohua Wu, Zhengkun Wang
We present a novel four-layer structure consisting of bottom, second, third, and surface layers in the sensing region, for a D-shaped step-index fiber-optic evanescent wave (FOEW) sensor. To reduce the background noise, the surface of the longitudinal section in the D-shaped region is coated with a light-absorbing film. We check the morphologies of the second and surface layers, examine the refractive indices (RIs) of the third and surface layers, and analyze the composition of the surface layer. We also investigate the effects of the thicknesses and RIs of the third and surface layers and the LA film on the light transmission and sensitivity of the FOEW sensors...
January 11, 2017: Biosensors & Bioelectronics
Jon Ashley, Mohammad-Ali Shahbazi, Krishna Kant, Vinayaka Aaydha Chidambara, Anders Wolff, Dang Duong Bang, Yi Sun
Molecularly imprinted polymers (MIPs) are biomimetics which can selectively bind to analytes of interest. One of the most interesting areas where MIPs have shown the biggest potential is food analysis. MIPs have found use as sorbents in sample preparation attributed to the high selectivity and high loading capacity. MIPs have been intensively employed in classical solid-phase extraction and solid-phase microextraction. More recently, MIPs have been combined with magnetic bead extraction, which greatly simplifies sample handling procedures...
January 11, 2017: Biosensors & Bioelectronics
A M Vinu Mohan, Joshua Ray Windmiller, Rupesh K Mishra, Joseph Wang
The present work describes an attractive skin-worn microneedle sensing device for the minimally invasive electrochemical monitoring of subcutaneous alcohol. The device consists of an assembly of pyramidal microneedle structures integrated with Pt and Ag wires, each with a microcavity opening. The microneedle aperture was modified by electropolymerizing o-phenylene diamine onto the Pt wire microtransducer, followed by the immobilization of alcohol oxidase (AOx) in an intermediate chitosan layer, along with an outer Nafion layer...
January 10, 2017: Biosensors & Bioelectronics
Ming-Yang Pan, Kuang-Li Lee, Likarn Wang, Pei-Kuen Wei
A chip-based ultrasensitive surface plasmon resonance (SPR) sensor in a checkerboard nanostructure on plastic substrates is presented for digital detection. The sensing elements on the checkerboard are composed of silver-capped nanoslit arrays, which were fabricated using the thermal-embossing nanoimprint method, to meet the demand for low-cost and rapid fabrication. Sharp Fano resonances in the optimized nanoslit arrays provide high-intensity sensitivities (20,000% per refractive index unit), with an element size of 12...
January 7, 2017: Biosensors & Bioelectronics
Kuncheng Yang, Shanshan Wang, Yingyi Wang, Hong Miao, Xiaoming Yang
Herein, carbon dots (CD@Papain) from papain have been originally synthesized in aqueous solution along with a quantum yield of 6.2%, and showed cyan fluorescence at 435nm. Meanwhile, papain-templated Au nanoclusters (AuNCs@Papain) were prepared with the same precursor. On the basis of the two types of nanomaterials, CD@Papain and AuNCs@Papain have been designed to assemble as one nanosensor (termed as CD-AuNCs@Papain) through a typical cross-linking reaction. Significantly, it not only emitted the dual-emission fluorescent signals with the same excitation, but also can assay multiple targets through exhibiting cyan, yellow, and red emission respectively...
January 7, 2017: Biosensors & Bioelectronics
Jinzhi Lv, Yanming Miao, Jiajia Yang, Jin Qin, Dongxia Li, Guiqin Yan
A QDs-DNA nano-probe was made by combining Mn-doped ZnS room-temperature phosphorescence (RTP) quantum dots (QDs) and DNA. Then an RTP sensor for quantitative detection of genetically-modified mark sequence cauliflower mosaic virus 35S promoter (Ca MV 35S) DNA was built on basis of phosphorescent resonance energy transfer (PRET). The underlying principles were that a QDs-DNA water-soluble nano-probe was built by connecting single-strand DNA to the surfaces of QDs via a ligand exchange method. This probe had good RTP performance and could well identify Ca MV 35S...
January 7, 2017: Biosensors & Bioelectronics
Zhaoyang Chen, Qian Sun, Yuhua Yao, Xiaoxiang Fan, Weibing Zhang, Junhong Qian
A fluorescence "off-on" probe CMP for thiols was designed with coumarin as the fluorophore and maleimide as the receptor. The fluorescence of the coumarin was quenched through photoinduced electron transfer (PET) from the fluorophore to maleimide group. The Michael addition of the mercapto group toward maleimide formed a thioether with relatively weak fluorescence. The intramolecular nucleophilic substitution of amino group in cysteine (Cys) to alkylthio produced a much stronger fluorescent amino adduct, which was supported by UPLC-MS and NMR titration...
January 7, 2017: Biosensors & Bioelectronics
Hui Jin, Rijun Gui, Jianbo Yu, Wei Lv, Zonghua Wang
Previously developed electrochemical biosensors with single-electric signal output are probably affected by intrinsic and extrinsic factors. In contrast, the ratiometric electrochemical biosensors (RECBSs) with dual-electric signal outputs have an intrinsic built-in correction to the effects from system or background electric signals, and therefore exhibit a significant potential to improve the accuracy and sensitivity in electrochemical sensing applications. In this review, we systematically summarize the fabrication strategies, sensing modes and analytical applications of RECBSs...
January 7, 2017: Biosensors & Bioelectronics
Shaoliang Dai, Shijia Wu, Nuo Duan, Jian Chen, Zhigao Zheng, Zhouping Wang
We developed an ultrasensitive luminescence resonance energy transfer (LRET) aptasensor for Ochratoxin A (OTA) detection, using core/shell upconversion nanoparticles (CS-UCNPs) as luminophores. The OTA aptamer was tagged to CS-UCNPs as energy donor and graphene oxide (GO) acted as energy acceptor. The π-π stacking interaction between the aptamer and GO brought CS-UCNPs and GO in close proximity hence initiated the LRET process resulting in quenching of CS-UCNPs luminescence. A linear calibration was obtained between the luminescence intensity and the logarithm of OTA concentration in the range from 0...
January 6, 2017: Biosensors & Bioelectronics
Shangyuan Feng, Zuci Zheng, Yuanji Xu, Jinyong Lin, Guannan Chen, Cuncheng Weng, Duo Lin, Sufang Qiu, Min Cheng, Zufang Huang, Lan Wang, Rong Chen, Shusen Xie, Haishan Zeng
The search for tumor biomarkers in the urine for cancer diagnosis is currently a hot topic in clinical oncology, with potential for cancer screening and diagnosis. Modified nucleosides excreted through the urine are considered to be a general tumor marker for various cancer types. Herein, we explore a new method that utilizes surface-enhanced Raman scattering (SERS) spectroscopy to obtain a complete biochemical profile of urinary modified nucleosides. In our method, modified nucleosides are first isolated from urine sample utilizing the excellent separation ability of affinity chromatography; then supplemented with gold (Au) nanoparticles as substrate for SERS spectroscopy analysis...
January 5, 2017: Biosensors & Bioelectronics
Lingyi Lan, Yao Yao, Jianfeng Ping, Yibin Ying
Antibiotics are able to be accumulated in human body by food chain and may induce severe influence to human health and safety. Hence, the development of sensitive and simple methods for rapid evaluation of antibiotic levels is highly desirable. Nanomaterials with excellent electronic, optical, mechanical, and thermal properties have been recognized as one of the most promising materials for opening new gates in the development of next-generation biosensors. This review highlights the current advances in the nanomaterial-based biosensors for antibiotics detection...
January 5, 2017: Biosensors & Bioelectronics
Hoon Jun Kim, Kyung-Sik Lee, Yong-Jun Jeon, Ik-Soo Shin, Jong-In Hong
Elevated levels of plasma homocysteine (Hcy) are an independent risk factor for cardiovascular disease. Although a routine, rapid, and simple determination of Hcy levels is highly desired, the existing methods are practically limited because of complicated sample preparation and bulky instrumentation. Herein, we report a chemodosimetric approach for one-step analysis of Hcy levels based on the electrochemiluminescence (ECL). A rationally designed cyclometalated iridium(III) complex possessing a phenylisoquinoline main ligand underwent a selective ring-formation reaction with Hcy to generate a binding adduct, which enabled producing highly luminescent excited states, and yielded strong ECL signals on the surface of electrode without any use of enzymes or antibodies...
January 5, 2017: Biosensors & Bioelectronics
Pramod Kumar Mehta, Hyeri Lee, Keun-Hyeung Lee
The selective and sensitive detection of heparin, an anticoagulant in clinics as well as its contaminant oversulfated chondroitin sulfate (OSCS) is of great importance. We first reported a ratiometric sensing method for heparin as well as OSCS contaminants in heparin using a fluorescent peptidyl probe (Pep1, pyrene-GSRKR) and heparin-digestive enzyme. Pep1 exhibited a highly sensitive ratiometric response to nanomolar concentration of heparin in aqueous solution over a wide pH range (2~11) and showed highly selective ratiometric response to heparin among biological competitors such as hyaluronic acid and chondroitin sulfate...
January 4, 2017: Biosensors & Bioelectronics
Rinku Chhasatia, Martin J Sweetman, Frances J Harding, Michaela Waibel, Tom Kay, Helen Thomas, Thomas Loudovaris, Nicolas H Voelcker
A label-free porous silicon (pSi) based, optical biosensor, using both an antibody and aptamer bioreceptor motif has been developed for the detection of insulin. Two parallel biosensors were designed and optimised independently, based on each bioreceptor. Both bioreceptors were covalently attached to a thermally hydrosilylated pSi surface though amide coupling, with unreacted surface area rendered stable and low fouling by incorporation of PEG moieties. The insulin detection ability of each biosensor was determined using interferometric reflectance spectroscopy, using a range of different media both with and without serum...
January 4, 2017: Biosensors & Bioelectronics
Sarah Nocchi, Sebastian Björklund, Birgitta Svensson, Johan Engblom, Tautgirdas Ruzgas
A skin covered oxygen electrode, SCOE, was constructed with the aim to study the enzyme catalase, which is part of the biological antioxidative system present in skin. The electrode was exposed to different concentrations of H2O2 and the amperometric current response was recorded. The observed current is due to H2O2 penetration through the outermost skin barrier (referred to as the stratum corneum, SC) and subsequent catalytic generation of O2 by catalase present in the underlying viable epidermis and dermis...
January 3, 2017: Biosensors & Bioelectronics
K Du, H Cai, M Park, T A Wall, M A Stott, K J Alfson, A Griffiths, R Carrion, J L Patterson, A R Hawkins, H Schmidt, R A Mathies
An automated microfluidic sample preparation multiplexer (SPM) has been developed and evaluated for Ebola virus detection. Metered air bubbles controlled by microvalves are used to improve bead-solution mixing thereby enhancing the hybridization of the target Ebola virus RNA with capture probes bound to the beads. The method uses thermally stable 4-formyl benzamide functionalized (4FB) magnetic beads rather than streptavidin coated beads with a high density of capture probes to improve the target capture efficiency...
January 3, 2017: Biosensors & Bioelectronics
Anran Gao, Xun Yang, Jing Tong, Lin Zhou, Yuelin Wang, Jianlong Zhao, Hongju Mao, Tie Li
In this work, a real-time assay for highly sensitive, label-free, multiplexed electrical detection of lung cancer biomarkers was developed by using silicon nanowire field-effect (SiNW-FET) devices. Highly responsive SiNW arrays were fabricated using a CMOS-compatible anisotropic self-stop etching technique with mass reproducibility and low cost character. The SiNW nanosensor was integrated with PDMS microfluidic device, which allows rapid analyte delivery, makes the analysis to be conducted using exceedingly small samples and enables potential multiplexed detection...
January 3, 2017: Biosensors & Bioelectronics
Shu Zhu, Xia Lin, Peiyao Ran, Qiao Xia, Chengcheng Yang, Jiao Ma, Yingzi Fu
A novel solid-state electrochemiluminesence (ECL) "on-off" switch system for highly sensitive detection of tryptophan based on the luminescence-functionalized ruthenium metal-organic framework (Ru-MOF) nanoflowers and CdS quantum dots (CdSQDs) was described. Ru-MOF nanoflowers were prepared by a one-step solvothermal method at low temperature and characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectra and fluorescence (FL) spectra...
January 3, 2017: Biosensors & Bioelectronics
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