A comprehensive review on nano-molybdenum disulfide/DNA interfaces as emerging biosensing platforms

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Manil Kukkar, Girish C. Mohanta, Satish K. Tuteja, Parveen Kumar, Akhshay Singh Bhadwal, Pallabi Samaddar, Ki-Hyun Kim, Akash Deep
The development of nucleic acid-based portable platforms for the real-time analysis of diseases has attracted considerable scientific and commercial interest. Recently, 2D layered molybdenum sulfide (2D MoS2 from here on) nanosheets have shown great potential for the development of next-generation platforms for efficient signal transduction. Through combination with DNA as a biorecognition medium, MoS2 nanostructures have opened new opportunities to design and construct highly sensitive, specific, and commercially viable sensing devices. The use of specific short ssDNA sequences like aptamers has been proven to bind well with the unique transduction properties of 2D MoS2 nanosheets to realize aptasensing devices. Such sensors can be operated on the principles of fluorescence, electro-cheumuluminescence, and electrochemistry with many advantageous features (e.g., robust biointerfacing through various conjugation chemistries, facile sensor assembly, high stability with regard to temperature/pH, and high affinity to target). This review encompasses the state of the art information on various design tactics and working principles of MoS2/DNA sensor technology which is emerging as one of the most sought-after and valuable fields with the advent of nucleic acid inspired devices. To help achieve a new milestone in biosensing applications, great potential of this emerging technique is described further with regard to sensitivity, specificity, operational convenience, and versatility.



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An optofluidic metasurface for lateral flow-through detection of breast cancer biomarker

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Yifei Wang, Md. Azahar Ali, Edmond K.C. Chow, Liang Dong, Meng Lu
The rapid growth of point-of-care tests demands for biosensors with high sensitivity and small size. This paper demonstrates an optofluidic metasurface that combines silicon-on-insulator (SOI) nanophotonics and nanofluidics to realize a high-performance, lateral flow-through biosensor. The metasurface is made of a periodic array of silicon nanoposts on an SOI substrate, and functionalized with specific receptor molecules. Bonding of a polydimethylsiloxane slab directly onto the surface results in an ultracompact biosensor, where analyte solutions are restricted to flow only in the space between the nanoposts. No flow exists above the nanoposts. This sensor design overcomes the issue with diffusion-limited detection of many other biosensors. The lateral flow-through feature, in conjunction with high-Q resonance modes associated with optical bound states of the metasurface, offers an improved sensitivity to subtle molecule-bonding induced changes in refractive index. The device exhibits a resonance mode around 1550 nm wavelength and provides an index sensitivity of 720 nm/RIU. Biosensing is conducted to detect the epidermal growth factor receptor 2 (ErbB2), a protein biomarker for early-stage breast cancer screening, by monitoring resonance wavelength shifts in response to specific analyte-ligand binding events at the metasurface. The limit of detection of the device is 0.7 ng mL⁻¹ for ErbB2.



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Silver-dendrimer nanocomposites as oligonucleotide labels for electrochemical stripping detection of DNA hybridization

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Xin Jin, Ling Zhou, Bo Zhu, Xue Jiang, Ningning Zhu
Silver-dendrimer nanocomposites were synthesized and used as oligonucleotide labels for electrochemical stripping detection of DNA hybridization. The synthesized silver-dendrimer nanocomposites were characterized by UV–vis spectrophotometry, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Ratios of silver/dendrimer were optimized in order to obtain stable nanocomposites with maximal silver loading in the interior of a polymeric shell. The silver-dendrimer nanocomposites were attached to sequence-known DNA probes specific to colitoxin, and used to detect probe hybridization by dissolution of the silver nanoparticles in the interior of dendrimer in a diluted nitric acid, followed by measurement of Ag⁺ ions by anodic stripping voltammetry (ASV). Use of differential pulse voltammetry for the stripping step, along with optimization of the ASV conditions, enabled a detection limit of 0.78 pM. The present strategy, in combination with dendrimer-encapsulated copper labeled oligonucleotides probe reported previously, could potentially be used to detect single or multiple DNA targets in one sample.



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Signal-on electrochemiluminescence biosensor for microRNA-319a detection based on two-stage isothermal strand-displacement polymerase reaction

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Minghui Wang, Yunlei Zhou, Huanshun Yin, Wenjing Jiang, Haiyan Wang, Shiyun Ai
MicroRNAs play crucial role in regulating gene expression in organism, thus it is very necessary to exploit an efficient method for the sensitive and specific detection of microRNA. Herein, a signal-on electrochemiluminescence biosensor was fabricated for microRNA-319a detection based on two-stage isothermal strand-displacement polymerase reaction (ISDPR). In the presence of target microRNA, amounts of trigger DNA could be generated by the first ISDPR. Then, the trigger DNA and the primer hybridized simultaneously with the hairpin probe to open the stem of the probe, and then the ECL signal will be emitted. In the presence of phi29 DNA polymerase and dNTPs, the trigger DNA could be displaced to initiate a new cycle which was the second ISDPR. Due to the two-stage amplification, this method presented excellent detection sensitivity with a low detection limit of 0.14 fM. Moreover, the applicability of the developed method was demonstrated by detecting the change of microRNA-319a content in the leaves of rice seedlings after the rice seeds were incubated with chemical mutagen of ethyl methanesulfonate.

Graphical abstract

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A nonenzymatic DNA nanomachine for biomolecular detection by target recycling of hairpin DNA cascade amplification

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Jiao Zheng, Ningxing Li, Chunrong Li, Xinxin Wang, Yucheng Liu, Guobin Mao, Xinghu Ji, Zhike He
Synthetic enzyme-free DNA nanomachine performs quasi-mechanical movements in response to external intervention, suggesting the promise of constructing sensitive and specific biosensors. Herein, a smart DNA nanomachine biosensor for biomolecule (such as nucleic acid, thrombin and adenosine) detection is developed by target-assisted enzyme-free hairpin DNA cascade amplifier. The whole DNA nanomachine system is constructed on gold nanoparticle which decorated with hundreds of locked hairpin substrate strands serving as DNA tracks, and the DNA nanomachine could be activated by target molecule toehold-mediated exchange on gold nanoparticle surface, resulted in the fluorescence recovery of fluorophore. The process is repeated so that each copy of the target can open multiplex fluorophore-labeled hairpin substrate strands, resulted in amplification of the fluorescence signal. Compared with the conventional biosensors of catalytic hairpin assembly (CHA) without substrate in solution, the DNA nanomachine could generate 2–3 orders of magnitude higher fluorescence signal. Furthermore, the DNA nanomachine could be used for nucleic acid, thrombin and adenosine highly sensitive specific detection based on isothermal, and homogeneous hairpin DNA cascade signal amplification in both buffer and a complicated biomatrix, and this kind of DNA nanomachine could be efficiently applied in the field of biomedical analysis.



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A highly specific and ultrasensitive near-infrared fluorescent probe for imaging basal hypochlorite in the mitochondria of living cells

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Baocun Zhu, Liu Wu, Meng Zhang, Yawei Wang, Caiyun Liu, Zuokai Wang, Qingxia Duan, Pan Jia
The development of highly specific and ultrasensitive fluorescent probes for tracking basal mitochondrial hypochlorite is very important to unravel its diverse cellular functions in the mitochondria of living cells. In this paper, we have developed a water-soluble, mitochondria-targeted near-infrared fluorescent probe NB-OCl for selectively measuring OCl^- in the presence of higher concentration (500 μM) other biologically important substances. Surprisingly, the obtained results demonstrated that probe NB-OCl could sensitively determine OCl^- in the range of 0–200 pM with the detection limit of 10.8 pM. To the best of our knowledge, NB-OCl is the first fluorescent probe for the specific determination of OCl^- at the picomolar level. Moreover, probe NB-OCl exhibits a fast response for OCl^- (< 5 s), which would be in favor of tracking the highly reactive and short-lived OCl^- in the living systems. The preeminent recognition properties of probe NB-OCl enable its applications in the monitoring of basal OCl^- and the fluctuations of endogenous/exogenous OCl^- levels in the mitochondria of living cells.



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Hierarchical CuInS2-based heterostructure: Application for photocathodic bioanalysis of sarcosine

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Xin-Yuan Jiang, Ling Zhang, Yi-Li Liu, Xiao-Dong Yu, Yan-Yu Liang, Peng Qu, Wei-Wei Zhao, Jing-Juan Xu, Hong-Yuan Chen
In this study, on the basis of hierarchical CuInS2-based heterostructure, a novel cathodic photoelectrochemical (PEC) enzymatic bioanalysis of the sarcosine detection was reported. Specifically, heterostructured CuInS2/NiO/ITO photocathode was prepared and sarcosine oxidases (SOx) were integrated for the construction of the enzymatic biosensor. In the bioanalysis, the O2-dependent suppression of the cathodic photocurrent can be observed due to the competition between the as-fabricated O2-sensitive photocathode and the SOx-catalytic event toward O2 reduction. Based on the sarcosine-controlled O2 concentration, a novel photocathodic enzymatic biosensor could be realized for the sensitive and specific sarcosine detection. This work manifested the great potential of CuInS2-based heterostructure as a novel platform for future PEC bioanalytical development and also a PEC method for sarcosine detection, which could be easily extended to numerous other enzymatic systems and to our knowledge has not been reported. This work is expected to stimulate more interest in the design and implementation of numerous CuInS2-based heterostructured photocathodic enzymatic sensing.



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Risk stratification of heart failure from one drop of blood using hand-held biosensor for BNP detection

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Indu Sarangadharan, Shin-Li Wang, Tse-Yu Tai, Anil Kumar Pulikkathodi, Chen-Pin Hsu, Hui-Hua Kenny Chiang, Lawrence Yu-Min Liu, Yu-Lin Wang
Continued risk assessment by evaluating cardiac biomarkers in healthy and unhealthy individuals can lower the mortality rate of cardiovascular diseases (CVDs). In this research, we have developed a hand-held biosensor system to rapidly screen for brain natriuretic peptide (BNP) from a single drop of whole blood. The sensor methodology is based on extended gate design of electrical double layer (EDL) field effect transistor (FET), that can directly detect BNP in whole blood, without extensive sample pre-treatments, thereby eliminating the limitations of charge screening in high ionic strength solutions. A simple sensor array chip is fabricated to integrate with the MOSFET sensor system. Sensing characteristics are elucidated using purified BNP samples in 1 × PBS (with 4% BSA), spiked BNP samples in whole blood and clinical whole blood samples. The blood cells can be gravitationally separated without the use of any external actuation. The sensor exhibits very high sensitivity over wide dynamic range of detection. The sensing characteristics are not adversely affected by the presence of background proteins or blood cells, even without gravitational blood cell separation. Thus, the biosensor system can allow users to perform rapid whole blood diagnostics with minimal user protocols, in 5 min. The features of high sensitivity, cost-effectiveness and convenience of usage empower this technology to revolutionize the mobile diagnostics and healthcare industry.



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Gold-copper bimetallic nanoparticles supported on nano P zeolite modified carbon paste electrode as an efficient electrocatalyst and sensitive sensor for determination of hydrazine

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Fatemeh Amiripour, Seyed Naser Azizi, Shahram Ghasemi
In this report, a facile, efficient and low cost electrochemical sensor based on bimetallic Au-Cu nanoparticles supported on P nanozeolite modified carbon paste electrode (Au-Cu/NPZ/CPE) was constructed and its efficiency for determination of hydrazine in trace level was studied. For this purpose, agro waste material, stem sweep ash (SSA) was employed as the starting material (silica source) for the synthesis of nano P zeolite (NPZ). After characterization of the synthesized NPZ by analytical instruments (scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy), construction of Au-Cu/NPZ/CPE was performed by three steps procedure involving preparation of nano P zeolite modified carbon paste electrode (NPZ/CPE), introducing Cu⁺² ions into nano zeolite structure by ion exchange and electrochemical reduction of Cu⁺² ions upon applying constant potential. This procedure is followed by partial replacement of Cu by Au due to galvanic replacement reaction (GRR). The electrochemical properties of hydrazine at the surface of Au-Cu/NPZ/CPE was evaluated using cyclic voltammetry (CV), amperometry, and chronoamperometry methods in 0.1 M phosphate buffer solution (PBS). It was found that the prepared sensor has higher electrocatalytic activity at a relatively lower potential compared to other modified electrodes including Au/NPZ/CPE, Cu/NPZ/CPE, Au-Cu/CPE and etc. Moreover, the proposed electrochemical sensor presented the favorable analytical properties for determination of hydrazine such as low detection limit (0.04 µM), rapid response time (3 s), wide linear range (0.01–150 mM), and high sensitivity (99.53 µA mM⁻¹) that are related to the synergic effect of bimetallic of Au-Cu, porous structure and enough surface area of NPZ. In addition, capability of Au-Cu/NPZ/CPE sensor was successfully tested in real samples with good accuracy and precision.

Graphical abstract

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Portable and quantitative point-of-care monitoring of Escherichia coli O157:H7 using a personal glucose meter based on immunochromatographic assay

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Haoran Huang, Guangying Zhao, Wenchao Dou
Here we innovate a portable and quantitative immunochromatographic assay (ICA) with a personal glucose meter (PGM) as readout for the detection of Escherichia coli O157:H7 (E. coli O157:H7). The carboxyl group coated Fe3O4 nanoparticles (MNPs) were synthesized by a one pot method and used as carriers of invertase and monoclonal antibody against E. coli O157:H7. Initially, the invertase and antibody double functionalized MNPs (Invertase-MNPs-IgG) conjugates were prepared and used as label probe in this assay system. Before laminating onto the baking card, the absorbent pad was soaked in sucrose solution and desiccated. MNPs produced brown band at the detection zone of the ICA when acting as direct labels. As they were also coupled with invertase, the invertase catalyzed the hydrolysis of sucrose on the absorbent pad into glucose, which was detected by the PGM. To increase the sensitivity, antibody functionalized MNPs were used to enrich E. coli O157:H7 from sample solution. The innovative aspect of this approach lies in the visualization and quantification of E. coli O157:H7 through Invertase-MNPs-IgG and the detection of glucose concentration using PGM. Although the feasibility is demonstrated using E. coli O157:H7 as a model analyte, this approach can be easily developed to be a universal analysis system and applied to detection of a wide variety of foodborne pathogens and protein biomarkers. This study proposed a qualitative and quantitative analysis device for the clinic diagnostics and food safety analysis.



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Electrochemical detection of influenza virus H9N2 based on both immunomagnetic extraction and gold catalysis using an immobilization-free screen printed carbon microelectrode

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Maher Sayhi, Oussama Ouerghi, Kamel Belgacem, Marwa Arbi, Yudum Tepeli, Abdeljalil Ghram, Ülkü Anik, Lars Österlund, Dhafer Laouini, Mohamed Fethi Diouani
Influenza is a viral infectious disease considered as a source of many health problems and enormous socioeconomic disruptions. Conventional methods are inadequate for in-field detection of the virus and generally suffer from being laborious and time-consuming. Thus, studies aiming to develop effective alternatives to conventional methods are urgently needed. In this work, we developed an approach for the isolation and detection of influenza A virus subtype H9N2. For this aim, two specific influenza receptors were used. The first, anti-matrix protein 2 (M2) antibody, was attached to iron magnetic nanoparticles (MNPs) and used for the isolation of the virus from allantoic fluid. The second biomolecule, Fetuin A, was attached to an electrochemical detectable label, gold nanoparticles (AuNPs), and used to detect the virus tacking advantage from fetuin-hemagglutinin interaction. The MNP-Influenza virus-AuNP formed complex was isolated and treated by an acid solution then the collected gold nanoparticles were deposited onto a screen printed carbon electrode. AuNPs catalyzes the hydrogen ions reduction in acidic medium while applying an appropriate potential, and the generated current signal was proportional to the virus titer. This approach allows the rapid detection of influenza virus A/H9N2 at a less than 16 HAU titer.



http://ift.tt/2sKIcAF

Sensitive, selective, disposable electrochemical dopamine sensor based on PEDOT-modified laser scribed graphene

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Guangyuan Xu, Zahraa A. Jarjes, Valentin Desprez, Paul A. Kilmartin, Jadranka Travas-Sejdic
The fabrication of a novel, and highly selective electrochemical sensor based on a poly(3,4-ethylenedioxythiophene) (PEDOT) modified laser scribed graphene (LSG), and detection of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA) is described. LSG electrodes were produced with a 3-dimensional macro-porous network and large electrochemically-active surface area via direct laser writing on polyimide sheets. PEDOT was electrodeposited on the LSG electrode, and the physical properties of the obtained films were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray diffraction microanalysis (EDAX). The modified electrodes were applied for the determination of DA in the presence of AA and UA using cyclic voltammetry (CV), and differential pulse voltammetry (DPV) techniques. The linear range for dopamine detection was found to be 1–150 µM with a sensitivity of 0.220 ± 0.011 µA μM⁻¹ and a detection limit of 0.33 µM; superior values to those obtained without PEDOT. For the first time, PEDOT-modified LSG have been fabricated and assessed for high-performance dopamine sensing using cost-effective, disposable electrodes, with potential for development in further sensing applications.



http://ift.tt/2sKI7Nn

Stretchable wireless system for sweat pH monitoring

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Wenting Dang, Libu Manjakkal, William Taube Navaraj, Leandro Lorenzelli, Vincenzo Vinciguerra, Ravinder Dahiya
Sensor-laden wearable systems that are capable of providing continuous measurement of key physiological parameters coupled with data storage, drug delivery and feedback therapy have attracted huge interest. Here we report a stretchable wireless system for sweat pH monitoring, which is able to withstand up to 53% uniaxial strain and more than 500 cycles to 30% strain. The stretchability of the pH sensor patch is provided by a pair of serpentine-shaped stretchable interconnects. The pH sensing electrode is made of graphite-polyurethane composite, which is suitable for biosensor application. The sensing patch validated through in-depth electrochemical studies, exhibits a pH sensitivity of 11.13 ± 5.8 mV/pH with a maximum response time of 8 s. Interference study of ions and analyte (Na⁺, K⁺ and glucose) in test solutions shows negligible influence on the pH sensor performance. The pH data can be wirelessly and continuously transmitted to smartphone through a stretchable radio-frequency-identification antenna, of which the radiating performance is stable under 20% strain, as proved by vector network analyzer measurement. To evaluate the full system, the pH value of a human sweat equivalent solution has been measured and wirelessly transmitted to a custom-developed smart phone App.



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Theoretical and experimental study for the biomimetic recognition of levothyroxine hormone on magnetic molecularly imprinted polymer

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Silio Lima Moura, Laura Martinez Fajardo, Leonardo dos Anjos Cunha, Maria Del Pilar Taboada Sotomayor, Francisco Bolivar Correto Machado, Luiz Fernando Araújo Ferrão, Maria Isabel Pividori
This study addresses the rational design of a magnetic molecularly imprinted polymer (magnetic-MIP) for the selective recognition of the hormone levothyroxine. The theoretical study was carried out by the density functional theory (DFT) computations considering dispersion interaction energies, and using the D2 Grimme's correction. The B97-D/def2-SV(P)/PCM method is used not only for studying the structure of the template the and monomer-monomer interactions, but also to assess the stoichiometry, noncovalent binding energies, solvation effects and thermodynamics properties such as binding energy. Among the 13 monomers studied in silico, itaconic acid is the most suitable according to the thermodynamic values. In order to assess the efficiency of the computational study, three different magnetic-MIPs based on itaconic acid, acrylic acid and acrylamide were synthesized and experimentally compared. The theoretical results are in agreement with experimental binding studies based on laser confocal microscopy, magneto-actuated immunoassay and electrochemical sensing. Furthermore, and for the first time, the direct electrochemical sensing of L-thyroxine preconcentrated on magnetic-MIP was successfully performed on magneto-actuated electrodes within 30 min with a limit of detection of as low as 0.0356 ng mL⁻¹ which cover the clinical range of total L-thyroxine. Finally, the main analytical features were compared with the gold standard method based on commercial competitive immunoassays. This work provides a thoughtful strategy for magnetic molecularly imprinted polymer design, synthesis and application, opening new perspectives in the integration of these materials in magneto-actuated approaches for replacing specific antibodies in biosensors and microfluidic devices.



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AuNPs/CNOs/SWCNTs/chitosan-nanocomposite modified electrochemical sensor for the label-free detection of carcinoembryonic antigen

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Mohammad Rizwan, Syazwani Elma, Syazana Abdullah Lim, Minhaz Uddin Ahmed
In this work, a nanocomposite of gold nanoparticles (AuNPs), carbon nano-onions (CNOs), single-walled carbon nanotubes (SWCNTs) and chitosan (CS) (AuNPs/CNOs/SWCNTs/CS) was prepared for the development of highly sensitive electrochemical immunosensor for the detection of carcinoembryonic antigen (CEA), clinical tumor marker. Firstly, layer-by-layer fabrication of the CEA-immunosensors was studied using cyclic voltammetry (CV) and square wave voltammetry (SWV). By combining the advantages of large surface area and electronic properties of AuNPs, CNOs, SWCNTs, and film forming properties of CS, AuNPs/CNOs/SWCNTs/CS-nanocomposite-modified glassy carbon electrode showed a 200% increase in effective surface area and electronic conductivity. The calibration plot gave a negative linear relationship between log[concentration] of CEA and electrical current with a correlation coefficient of 0.9875. The CEA-immunosensor demonstrated a wide linear detection range of 100 fg mL⁻¹ to 400 ng mL⁻¹ with a low detection limit of 100 fg mL⁻¹. In addition to high sensitivity, reproducibility and large stability, CEA-immunosensor provided an excellent selectivity and resistant-to-interference in the presence of other antigens in serum and hence a potential to be used with real samples.



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Nursing and Politics.

Author: Brodbeck, Jessica MSN, RN, AOCNS

Page: 10

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Nursing and Politics.

Author: Newcomb, Patricia PhD, RN, CPNP

Page: 10

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Ethical Issues.

Author: Marylyn, via ajnoffthecharts.com

Page: 10

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AMA Resolution Opposes Independent Practice by APRNs.

Author: Sofer, Dalia

Page: 12

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ED Visits for Self-Harm by Girls Are on the Rise.

Author: Stockwell, Serena

Page: 13

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