scholarly journals Aptamer-Based Biosensing with a Cationic AIEgen

2019 ◽  
Vol 72 (8) ◽  
pp. 620 ◽  
Author(s):  
Tracey Luu ◽  
Mengjie Liu ◽  
Yilong Chen ◽  
Roozbeh Hushiarian ◽  
Anthony Cass ◽  
...  
Keyword(s):  
High Selectivity ◽  
Low Cost ◽  
Protein Detection ◽  
Specific Protein ◽  
Personal Health ◽  
Fluorescence Signal ◽  
Portable Devices ◽  
Dye Molecules ◽  
Working Mechanism ◽  
Aptamer Sequence

Fabrication of low-cost biosensing platforms with high selectivity and sensitivity is important for constructing portable devices for personal health monitoring. Herein, we report a simple biosensing strategy based on the combination of a cationic AIEgen (aggregation-induced emission fluorogen), TPE-2+, with an aptamer for specific protein detection. The target protein can displace the dye molecules on the dye–aptamer complex, resulting in changes in the fluorescence signal. Selectivity towards different targets can be achieved by simply changing the aptamer sequence. The working mechanism is also investigated.

Metal-organic framework derived metal oxide/reduced graphene oxide nanocomposite, a new tool for the determination of dipyridamole

2021 ◽  
Author(s):  
Naeime Salandari-Jolge ◽  
Ali A. Ensafi ◽  
Behzad Rezaei
Keyword(s):  
Myocardial Infarction ◽  
Graphene Oxide ◽  
High Performance ◽  
High Selectivity ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Heart Patients ◽  
Reduced Graphene ◽  
Metal Organic

Dipyridamole is a prescribed medication used to treat cardiovascular diseases, angina pectoris, imaging tests for heart patients, and myocardial infarction. Therefore, high selectivity and sensitivity, low cost, and high-performance speed...

scholarly journals Working Mechanism of Nonresonance Friction in Driving Linear Piezoelectric Motors with Rigid Shaking Beam

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Xifu Chen ◽  
Qian Lu ◽  
Weiqing Huang ◽  
Yin Wang
Keyword(s):  
Numerical Analysis ◽  
Normal Vibration ◽  
Low Cost ◽  
Theoretical Data ◽  
Friction Model ◽  
Working Mechanism ◽  
Ultrasonic Motors ◽  
Vibration Model ◽  
Piezoelectric Motors ◽  
Output Characteristics

A kind of nonresonance shaking beam motors is proposed with the advantages of simple structure, easy processing, and low cost due to its wide application prospects in precision positioning technology and precision instruments. The normal vibration model between the stator and slider is divided into contact and noncontact types to investigate the nonresonance friction drive principle for this motor. The microscopic kinematics model for stator protruding section and the interface friction model for motor systems during both operating stages are established. Accordingly, the trajectory of the stator protruding section consists of two different elliptical motions, which differ from those of resonance-type motors. The output characteristic of the nonresonance shaking beam motor is proposed under steady working conditions with reference to the research method of standing-wave-type ultrasonic motors. Numerical analysis is used to simulate the normal vibration and mechanical output characteristics of the motor. Experimental and theoretical data fitting validates the numerical analysis results and allows the future optimization of nonresonance-type motors.

scholarly journals Nucleic acid-based biosensors: analytical devices for prevention, diagnosis and treatment of diseases

Revista Vitae ◽  
2021 ◽  
Vol 28 (3) ◽  
Author(s):  
Laura Carvajal Barbosa ◽  
Diego Insuasty Cepeda ◽  
Andrés Felipe León Torres ◽  
Maria Mercedes Arias Cortes ◽  
Zuly Jenny Rivera Monroy ◽  
...  
Keyword(s):  
Food Safety ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Pathogenic Bacteria ◽  
High Selectivity ◽  
Low Cost ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Disease Status ◽  
Public Health Issue

BACKGROUND : Biosensing techniques have been the subject of exponentially increasing interest due to their performance advantages such as high selectivity and sensitivity, easy operation, low cost, short analysis time, simple sample preparation, and real-time detection. Biosensors have been developed by integrating the unique specificity of biological reactions and the high sensitivity of physical sensors. Therefore, there has been a broad scope of applications for biosensing techniques, and nowadays, they are ubiquitous in different areas of environmental, healthcare, and food safety. Biosensors have been used for environmental studies, detecting and quantifying pollutants in water, air, and soil. Biosensors also showed great potential for developing analytical tools with countless applications in diagnosing, preventing, and treating diseases, mainly by detecting biomarkers. Biosensors as a medical device can identify nucleic acids, proteins, peptides, metabolites, etc.; these analytes may be biomarkers associated with the disease status. Bacterial food contamination is considered a worldwide public health issue; biosensor-based analytical techniques can identify the presence or absence of pathogenic agents in food. OBJECTIVES: The present review aims to establish state-of-the-art, comprising the recent advances in the use of nucleic acid-based biosensors and their novel application for the detection of nucleic acids. Emphasis will be given to the performance characteristics, advantages, and challenges. Additionally, food safety applications of nucleic acid-based biosensors will be discussed. METHODS: Recent research articles related to nucleic acid-based biosensors, biosensors for detecting nucleic acids, biosensors and food safety, and biosensors in environmental monitoring were reviewed. Also, biosensing platforms associated with the clinical diagnosis and food industry were included. RESULTS: It is possible to appreciate that multiple applications of nucleic acid-based biosensors have been reported in the diagnosis, prevention, and treatment of diseases, as well as to identify foodborne pathogenic bacteria. The use of PNA and aptamers opens the possibility of developing new biometric tools with better analytical properties. CONCLUSIONS: Biosensors could be considered the most important tool for preventing, treating, and monitoring diseases that significantly impact human health. The aptamers have advantages as biorecognition elements due to the structural conformation, hybridization capacity, robustness, stability, and lower costs. It is necessary to implement biosensors in situ to identify analytes with high selectivity and lower detection limits.

Formation of Through-Glass-Via (TGV) by Photo-Chemical Etching with High Selectivity

2012 ◽  
Vol 2012 (1) ◽  
pp. 000785-000792
Author(s):  
Zingway Pei ◽  
Jui-Po Sun ◽  
Hsin-Chen Lai ◽  
Pei-Jer Tzeng ◽  
Cha-Hsin Lin ◽  
...  
Keyword(s):  
Chemical Etching ◽  
High Selectivity ◽  
Laser Energy ◽  
Low Cost ◽  
Etching Rate ◽  
Ultra Violet ◽  
Amorphous Region ◽  
Large Area ◽  
Micro Cracks ◽  
Via Hole

In this work, we utilize a photo-chemical etching (PCE) method to form through-glass-via (TGV). The PCE is a low cost, damage-free and potentially large-area method for TGV formation. An ultra-violet (355 nm) pulse laser was used to illuminate the glass surface. The illuminated region will crystallize after thermal annealing in a furnace. The crystallized glass shows much faster etching rate than the amorphous region in HF solution. For a relatively thick (600 nm) glass, a via-hole with diameter of around 60 μm was demonstrated in laser energy of 11 J/cm2. No laser damages were observed. In comparison, at least 10 times higher energy was required to drill a glass directly. Micro-cracks were form around the glass-via. In addition, a 40 selectivity was achieved to the crystallized and amorphous region. This simple and useful method paves a straight road for 3-D integration.

scholarly journals Steering Angle Assisted Vehicular Navigation Using Portable Devices in GNSS-Denied Environments

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1618 ◽  
Author(s):  
Mohamed Moussa ◽  
Adel Moussa ◽  
Naser El-Sheimy
Keyword(s):  
Low Cost ◽  
Measurement Unit ◽  
Steering Wheel ◽  
Portable Devices ◽  
Steering Angle ◽  
Navigation Solution ◽  
Land Vehicle ◽  
Land Vehicle Navigation ◽  
Novel Approach ◽  
Vehicle Acceleration

Recently, land vehicle navigation, and especially by the use of low-cost sensors, has been the object of a huge level of research interest. Consumer Portable Devices (CPDs) such as tablets and smartphones are being widely used by many consumers all over the world. CPDs contain sensors (accelerometers, gyroscopes, magnetometer, etc.) that can be used for many land vehicle applications such as navigation. This paper presents a novel approach for estimating steering wheel angles using CPD accelerometers by attaching CPDs to the steering wheel. The land vehicle change of heading is then computed from the estimated steering wheel angle. The calculated change of heading is used to update the navigation filter to aid the onboard Inertial Measurement Unit (IMU) through the use of an Extended Kalman Filter (EKF) in GNSS-denied environments. Four main factors that may affect the steering wheel angle accuracy are considered and modeled during steering angle estimations: static onboard IMU leveling, inclination angle of the steering wheel, vehicle acceleration, and vehicle inclination. In addition, these factors are assessed for their effects on the final result. Therefore, three methods are proposed for steering angle estimation: non-compensated, partially-compensated, and fully-compensated methods. A road experimental test was carried out using a Pixhawk (PX4) navigation system, iPad Air, and the OBD-II interface. The average Root Mean Square Error (RMSE) of the change of heading estimated by the proposed method was 0.033 rad/s. A navigation solution was estimated while changes of heading and forward velocity updates were used to aid the IMU during different GNSS signal outages. The estimated navigation solution is enhanced when applying the proposed updates to the navigation filter by 91% and 97% for 60 s and 120 s of GNSS signal outage, respectively, compared to the IMU standalone solution.

scholarly journals Automated 3D-printed unibody immunoarray for chemiluminescence detection of cancer biomarker proteins

Lab on a Chip ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 484-489 ◽  
Author(s):  
C. K. Tang ◽  
A. Vaze ◽  
J. F. Rusling
Keyword(s):  
Dynamic Range ◽  
Low Cost ◽  
Protein Detection ◽  
Cancer Biomarker ◽  
Chemiluminescence Detection ◽  
Large Dynamic Range ◽  
3D Printed

A valve-free, low cost 3D-printed device was designed for fast, low cost automated protein detection of PSA and PF-4 with a LOD of 0.5 pg mL−1 and a large dynamic range.

scholarly journals Novel Protein-Based Pneumococcal Vaccines: Assessing the Use of Distinct Protein Fragments Instead of Full-Length Proteins as Vaccine Antigens

Vaccines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Theano Lagousi ◽  
Paraskevi Basdeki ◽  
John Routsias ◽  
Vana Spoulou
Keyword(s):  
Low Cost ◽  
Specific Protein ◽  
Full Length ◽  
Pneumococcal Vaccines ◽  
Protein Antigens ◽  
Protein Fragments ◽  
Humoral And Cellular Immunity ◽  
Expression Variability ◽  
Efficient Protection ◽  
Antigenic Regions

Non-serotype-specific protein-based pneumococcal vaccines have received extensive research focus due to the limitations of polysaccharide-based vaccines. Pneumococcal proteins (PnPs), universally expressed among serotypes, may induce broader immune responses, stimulating humoral and cellular immunity, while being easier to manufacture and less expensive. Such an approach has raised issues mainly associated with sequence/level of expression variability, chemical instability, as well as possible undesirable reactogenicity and autoimmune properties. A step forward employs the identification of highly-conserved antigenic regions within PnPs with the potential to retain the benefits of protein antigens. Besides, their low-cost and stable construction facilitates the combination of several antigenic regions or peptides that may impair different stages of pneumococcal disease offering even wider serotype coverage and more efficient protection. This review discusses the up-to-date progress on PnPs that are currently under clinical evaluation and the challenges for their licensure. Focus is given on the progress on the identification of antigenic regions/peptides within PnPs and their evaluation as vaccine candidates, accessing their potential to overcome the issues associated with full-length protein antigens. Particular mention is given of the use of newer delivery system technologies including conjugation to Toll-like receptors (TLRs) and reformulation into nanoparticles to enhance the poor immunogenicity of such antigens.

scholarly journals LeafScope: A Portable High-Resolution Multispectral Imager for In Vivo Imaging Soybean Leaf

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2194
Author(s):  
Liangju Wang ◽  
Yunhong Duan ◽  
Libo Zhang ◽  
Jialei Wang ◽  
Yikai Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Cost ◽  
Small Region ◽  
Plant Phenotyping ◽  
Portable Devices ◽  
Hardware System ◽  
Soybean Plants ◽  
Water Treatments ◽  
Multispectral Imager

Portable devices for measuring plant physiological features with their isolated measuring chamber are playing an increasingly important role in plant phenotyping. However, currently available commercial devices of this type, such as soil plant analysis development (SPAD) meter and spectrometer, are dot meters that only measure a small region of the leaf, which does not perfectly represent the highly varied leaf surface. This study developed a portable and high-resolution multispectral imager (named LeafScope) to in-vivo image a whole leaf of dicotyledon plants while blocking the ambient light. The hardware system is comprised of a monochrome camera, an imaging chamber, a lightbox with different bands of light-emitting diodes (LEDs) array, and a microcontroller. During measuring, the device presses the leaf to lay it flat in the imaging chamber and acquires multiple images while alternating the LED bands within seconds in a certain order. The results of an experiment with soybean plants clearly showed the effect of nitrogen and water treatments as well as the genotype differences by the color and morphological features from image processing. We conclude that the low cost and easy to use LeafScope can provide promising imaging quality for dicotyledon plants, so it has great potential to be used in plant phenotyping.

scholarly journals Formaldehyde and Total VOC (TVOC) Commercial Low-Cost Monitoring Devices: From an Evaluation in Controlled Conditions to a Use Case Application in a Real Building

Chemosensors ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 8 ◽  
Author(s):  
Valérie Goletto ◽  
Geneviève Mialon ◽  
Timothé Faivre ◽  
Ying Wang ◽  
Isabelle Lesieur ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
General Public ◽  
Low Cost ◽  
Qualitative Evaluation ◽  
Experimental Methodology ◽  
Portable Devices ◽  
Test Case ◽  
Controlled Conditions ◽  
Volatile Organic

Formaldehyde and volatile organic compounds (VOCs) are major indoor pollutants with multiple origins. Standard methods exist to measure them that require analytical expertise and provide, at best, an average value of their concentrations. There is a need to monitor them continuously during periods of several days, weeks, or even months. Recently, portable devices have become available. Two categories of portable devices are considered in this research paper: connected objects for the general public (price <500 €) and monitoring portable devices for professional users (price in the range >500 to 5000 €). The ISO method (ISO 16000-29) describes the standard for VOC detector qualification. It is quite complex and is not well adapted for a first qualitative evaluation of these low-cost devices. In this paper, we present an experimental methodology used to evaluate commercial devices that monitor formaldehyde and/or total volatile organic compounds (TVOC) under controlled conditions (23 °C, 50–65% relative humidity (RH)). We conclude that none of the connected objects dedicated to the general public can provide reliable data in the conditions tested, not even for a qualitative evaluation. For formaldehyde monitoring, we obtained some promising results with a portable device dedicated to professional users. In this paper, we illustrate, with a real test case in an office building, how this device was used for a comparative analysis.

scholarly journals Functionally Modified Polyolefin-Based Separators for Lithium-Sulfur Batteries: Progress and Prospects

2020 ◽  
Vol 8 ◽  
Author(s):  
Jiaojiao Li ◽  
Zhen Xiao ◽  
Anqi Chen ◽  
Wenkui Zhang ◽  
Dongmin Zhu ◽  
...  
Keyword(s):  
Physical Adsorption ◽  
Rate Capability ◽  
Future Perspective ◽  
Portable Devices ◽  
Working Mechanism ◽  
Practical Utilization ◽  
Hybrid Mechanism ◽  
Lithium Sulfur Batteries ◽  
Intractable Problems ◽  
Lithium Sulfur

The ever-growing demand for portable devices and electric vehicles are drawing widespread attention to advanced energy storage systems. Over the past few decades, lithium-sulfur batteries (LSBs) have vast potential to act as the next-generation of rechargeable power source due to their high theoretical specific energy, cost-effectiveness, and environmental benignity. However, insufficient sulfur utilization, inferior cyclability, and rate capability originating from the intrinsic insulating features of the sulfur and notorious polysulfide shuttle are major obstacles to fulfilling the industrialization of LSBs. In this respect, the introduction of a functional barrier layer coating on a separator has been verified as an effective strategy to overcome the aforementioned intractable problems. In this review, we focus on summarizing the current progress of the modified polyolefin-based separators (known as functional separators), including functional separator facing cathodes and functional separator facing anodes. According to the working mechanism, functional separator facing cathodes are divided into physical adsorption separators, chemical adsorption separators, catalytic conversion separators, and multifunctional separators. Meanwhile, functional separator facing anodes are classified into physical barrier separators, induced lithium growth separators, regulated lithium nucleation separators, and hybrid mechanism separators. Finally, the future perspective coupled with the practical utilization of functional separators in LSBs is proposed.

Sign in / Sign up

Export Citation Format

Share Document