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Paper Based Analytical Device

Arvin Sain Tanwar, Sourabh Patidar, Saurabh Ahirwar, Sourav Dehingia, Parameswar Krishnan Iyer
Two "receptor-free" blue fluorescent conjugated polymers (CPs) of fluorene namely 9,9-bis(6-bromohexyl)-2-phenyl-9H-fluorene (PF1) and 9,9-bis(6-bromohexyl)-9H-fluorene (PF2) were synthesized using Suzuki cross coupling polymerization and oxidative coupling polymerization methods in high yields and well characterized by gel permeable chromatography, NMR, UV-vis, fluorescence and time-resolved photoluminescence (TRPL) spectroscopy. Both CPs explicitly recognized nitroexplosive picric acid (PA) and displayed a fluorescence quenching response in solution and on a solid support via the Inner Filter Effect (IFE) mechanism...
December 4, 2018: Analyst
Fanyu Zeng, Taotao Mou, Chengchen Zhang, Xiaoqing Huang, Bing Wang, Xing Ma, Jinhong Guo
SERS (Surface Enhanced Raman Spectroscopy) can realize fingerprint recognition of molecular samples with high detection accuracy and sensitivity. However, rapid and convenient measurement of the Raman spectra of analytes for a point-of-care test (POCT) has put forward a high demand for portable Raman spectrometers, as well as reliable SERS substrates. Hereby, we first utilize a smartphone as a miniaturized Raman spectral analyzer, which has the revolutionary advantages of a friendly human-machine interface, fast measurement time, and good sensitivity...
November 28, 2018: Analyst
Azadeh Nilghaz, Xiaonan Lu
This work demonstrates a sensitive and rapid method for the detection of antibiotic residues in food samples by employing the filtration behaviour of paper combined with aggregation and precipitation of chemical reagents. Using this concept, we successfully determined the presence of oxytetracycline and norfloxacin residues in pork using metal complexation on microfluidic paper-based analytical devices (μPADs). The base substrate (top layer of the device) was fabricated by printing letter channels of the words "oxytetracycline" and "norfloxacin" before functionalization with copper (II) sulfate pentahydrate in 0...
January 10, 2019: Analytica Chimica Acta
Fabiana S Felix, Alexandre L B Baccaro, Lúcio Angnes
Disposable immunosensors are analytical devices used for the quantification of a broad variety of analytes in different areas such as clinical, environmental, agricultural and food quality management. They detect the analytes by means of the strong interactions between antibodies and antigens, which provide concentration-dependent signals. For the herein highlighted voltammetric immunosensors, the analytical measurements are due to changes in the electrical signals on the surface of the transducers. The possibility of using disposable and miniaturized immunoassays is a very interesting alternative for voltammetric analyses, mainly, when associated with screen-printing technologies (screen-printed electrodes, SPEs), and microfluidic platforms...
November 24, 2018: Sensors
Xiu-Xiu Zhang, Jia-Juan Liu, Yu Cai, Shuang Zhao, Zhi-Yong Wu
A sensitive detection method combined with an effective on-line concentration may improve the analytical performance of a paper-based analytical device (PAD), and its merits of low cost and portability in POCT are fully demonstrated. Here, a sensitive PAD system with chemiluminescence (CL) detection and electrokinetic preconcentration was introduced, and the performance was demonstrated by the detection of hemin. A commercially available low cost and miniaturized optical detection module was used for the CL detection...
November 26, 2018: Analyst
Lei Huang, Guohua Hu, Chunyu Deng, Yuan Zhu, Binfeng Yun, Ruohu Zhang, Yiping Cui
In this paper, we theoretically propose an effective broadband absorption architecture in mid-infrared region based on strong coupling between the plasmonic resonance of graphene nanoribbons and the waveguide mode of a metal tapered groove. The special architecture facilitates two new hybrid modes splitting with very strong energy distribution on graphene ribbon, which results in the broadband absorption effect. To well explain these numerical results, an analytical dispersion relation of waveguide mode is obtained based on the classical LC circuit model...
October 29, 2018: Optics Express
Qiang Ren, Huaguang Bao, Sawyer D Campbell, Ludmila J Prokopeva, Alexander V Kildishev, Douglas H Werner
The discontinuous Galerkin time domain (DGTD) method and its recent flavor, the continuous-discontinuous Galerkin time domain (CDGTD) method, have been extensively applied to simulations in the radio frequency (RF) and microwave (MW) regimes due to their inherent ability to efficiently model multiscale problems. We propose to extend the CDGTD method to nanophotonics while exploiting its advantages which have already been established in the RF and MW regimes, such as domain decomposition, non-conformal meshing, high-order elements, and hp-refinement...
October 29, 2018: Optics Express
Hua Wang, Zhan Ma, Juanxiu Qin, Zhen Shen, Qian Liu, Xiaoyin Chen, Hengliang Wang, Zhenghua An, Wu Liu, Min Li
Community-acquired pneumonia (CAP) is the leading cause of mortality in children under five years of age, globally. Given that Streptococcus pneumoniae (S. pneumoniae) and Mycoplasma pneumoniae (M. pneumoniae) are the most common pathogens associated with CAP requiring hospital admission, a simple, low cost, highly sensitive method is in great need for immediate and early diagnosis of CAP. Herein, we report a versatile microfluidic chip platform integrated with loop-mediated isothermal amplification (LAMP) for simultaneous S...
November 12, 2018: Biosensors & Bioelectronics
Xu Long, Xiaodi Zhang, Wenbin Tang, Shaobin Wang, Yihui Feng, Chao Chang
It is challenging to evaluate constitutive behaviour by using conventional uniaxial tests for materials with limited sizes, considering the miniaturization trend of integrated circuits in electronic devices. An instrumented nanoindentation approach is appealing to obtain local properties as the function of penetration depth. In this paper, both conventional tensile and nanoindentation experiments are performed on samples of a lead-free Sn⁻3.0Ag⁻0.5Cu (SAC305) solder alloy. In order to align the material behaviour, thermal treatments were performed at different temperatures and durations for all specimens, for both tensile experiments and nanoindentation experiments...
November 20, 2018: Micromachines
Shuzhen Lv, Yun Tang, Kangyao Zhang, Dianping Tang
This work has looked to explore an innovative and powerful visible fluorescence immunoassay method through wet NH3 -triggered structural change of NH2 -MIL-125(Ti) impregnated on paper for the detection of carcinoembryonic antigen (CEA). Gold nanoparticles heavily functionalized with glutamate dehydrogenase (GDH) and secondary antibody were used for generation of wet NH3 with a sandwiched immunoassay format. Paper-based analytical device (PAD) coated with NH2 -MIL-125(Ti) exhibited good visible fluorescence intensity through wet NH3 -triggeried structural change with high accuracy and reproducibility...
November 26, 2018: Analytical Chemistry
Colin McGinty, Robert Reich, Harry Clark, Valerie Finnemeyer, Shaun Berry, Philip Bos
Microbolometers are the dominant technology for uncooled thermal imaging; however, devices based on a direct retardation measurement of a liquid crystal (LC) transducer pixel have been shown to have comparable sensitivity. In this paper, an approach for increasing LC transducer sensitivity utilizing an etalon structure is considered. A detailed design for an LC resonant cavity between dielectric mirrors is proposed and the performance is evaluated numerically. The measured quantity is the transmission of a visible wavelength through the etalon, which requires no thermal contact with the IR sensor...
October 1, 2018: Applied Optics
Qi Pan, Xiangming Wen, Zhaoming Lu, Linpei Li, Wenpeng Jing
With the new advancements in flight control and integrated circuit (IC) technology, unmanned aerial vehicles (UAVs) have been widely used in various applications. One of the typical application scenarios is data collection for large-scale and remote sensor devices in the Internet of things (IoT). However, due to the characteristics of massive connections, access collisions in the MAC layer lead to high power consumption for both sensor devices and UAVs, and low efficiency for the data collection. In this paper, a dynamic speed control algorithm for UAVs (DSC-UAV) is proposed to maximize the data collection efficiency, while alleviating the access congestion for the UAV-based base stations...
November 15, 2018: Sensors
Prinjaporn Teengam, Weena Siangproh, Adisorn Tuantranont, Tirayut Vilaivan, Orawon Chailapakul, Charles S Henry
A label-free electrochemical DNA sensor based on pyrrolidinyl peptide nucleic acid (acpcPNA)-immobilized on a paper-based analytical device (PAD) was developed. Unlike previous PNA-based electrochemical PAD (ePAD) sensors where the capture element was placed directly on the electrode, acpcPNA was covalently immobilized onto partially oxidized cellulose paper allowing regeneration by simple PAD replacement. As an example application, a sensor probe was designed for Mycobacterium tuberculosis (MTB) detection...
December 31, 2018: Analytica Chimica Acta
Georgia-Paraskevi Nikoleli, Dimitrios P Nikolelis, Christina G Siontorou, Marianna-Thalia Nikolelis, Stephanos Karapetis
The exploitation of lipid membranes in biosensors has provided the ability to reconstitute a considerable part of their functionality to detect trace of food toxicants and environmental pollutants. This paper reviews recent progress in biosensor technologies based on lipid membranes suitable for food quality monitoring and environmental applications. Numerous biosensing applications based on lipid membrane biosensors are presented, putting emphasis on novel systems, new sensing techniques, and nanotechnology-based transduction schemes...
November 14, 2018: Membranes
Debayan Das, Shovan Maity, Baibhab Chatterjee, Shreyas Sen
In this emerging data-driven world, secure and ubiquitous authentication mechanisms are necessary prior to any confidential information delivery. Biometric authentication has been widely adopted as it provides a unique and non-transferable solution for user authentication. In this article, the authors envision the need for an infield, remote and on-demand authentication system for a highly mobile and tactical environment, such as critical information delivery to soldiers in a battlefield. Fingerprint-based in-field biometric authentication combined with the conventional password-based techniques would ensure strong security of critical information delivery...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Tsui-Hsuan Chang, Kuo-Hao Tung, Po-Wen Gu, Tzung-Hai Yen, Chao-Min Cheng
Paraquat intoxication is characterized by acute kidney injury and multi-organ failure, causing substantial mortality and morbidity. This study aims to develop a 2-in-1 paper-based analytical device to detect the concentrations of paraquat and creatinine in human serum, which can help clinicians diagnose patients with paraquat poisoning in a more rapid and geographically unrestricted manner. The procedure involves fabrication of a paper-based analytical device, i.e., printing of design on a filter paper, heating of wax-printed micro zone plates so as molten wax diffusing into and completely through the paper to the other side, forming hydrophobic boundaries that could act as detection zones for the paraquat colorimetric assay, and finally analysis using ImageJ software...
November 12, 2018: Micromachines
Shih-Jie Lo, Chen-Meng Kuan, Min-Wei Hung, Yun Fu, J Andrew Yeh, Da-Jeng Yao, Chao-Min Cheng
This article unveiled the development of an inexpensive, lightweight, easy-to-use, and portable fluorescence imaging device for paper-based analytical applications. We used commercial fluorescent dyes, as proof of concept, to verify the feasibility of our fluorescence imaging device for bioanalysis. This approach may provide an alternative method for nucleotide detection and semen analysis, using a miniaturized fluorescence reader that is more compact and portable than conventional analytical equipment.
August 20, 2018: Micromachines
Jianxin Han, Lei Li, Gang Jin, Jingjing Feng, Baizhou Li, Haili Jia, Wenkui Ma
Natural frequency and frequency response are two important indicators for the performances of resonant microelectromechanical systems (MEMS) devices. This paper analytically and numerically investigates the vibration identification of the primary resonance of one type of folded-MEMS comb drive resonator. The governing equation of motion, considering structure and electrostatic nonlinearities, is firstly introduced. To overcome the shortcoming of frequency assumption in the literature, an improved theoretical solution procedure combined with the method of multiple scales and the homotopy concept is applied for primary resonance solutions in which frequency shift due to DC voltage is thoroughly considered...
August 1, 2018: Micromachines
Md Almostasim Mahmud, Eric J M Blondeel, Moufeed Kaddoura, Brendan D MacDonald
In this paper, we determine the smallest feature size that enables fluid flow in microfluidic paper-based analytical devices (µPADs) fabricated by laser cutting. The smallest feature sizes fabricated from five commercially available paper types: Whatman filter paper grade 50 (FP-50), Whatman 3MM Chr chromatography paper (3MM Chr), Whatman 1 Chr chromatography paper (1 Chr), Whatman regenerated cellulose membrane 55 (RC-55) and Amershan Protran 0.45 nitrocellulose membrane (NC), were 139 ± 8 µm, 130 ± 11 µm, 103 ± 12 µm, 45 ± 6 µm, and 24 ± 3 µm, respectively, as determined experimentally by successful fluid flow...
May 7, 2018: Micromachines
Sebastian Uhlig, Matthieu Gaudet, Sergiu Langa, Klaus Schimmanz, Holger Conrad, Bert Kaiser, Harald Schenk
In this paper, an in-plane reciprocating displacement micropump for liquids and gases which is actuated by a new class of electrostatic bending actuators is reported. The so-called "Nano Electrostatic Drive" is capable of deflecting beyond the electrode gap distance, enabling large generated forces and deflections. Depending on the requirements of the targeted system, the micropump can be modularly designed to meet the specified differential pressures and flow rates by a serial and parallel arrangement of equally working pumping base units...
April 18, 2018: Micromachines
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