scholarly journals A Multi-Chamber Paper-Based Platform for the Detection of Amyloid β Oligomers 42 via Copper-Enhanced Gold Immunoblotting

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 948
Author(s):  
Le-Minh-Tu Phan ◽  
Sungbo Cho
Keyword(s):  
Limit Of Detection ◽  
Amyloid Β ◽  
Cost Savings ◽  
Require Time ◽  
Sensing Platform ◽  
Wax Printing ◽  
Reaction Chambers ◽  
Gold Nanoprobe ◽  
Robust Sensing ◽  
Technical Professionals

The early diagnosis of Alzheimer’s disease (AD) remains a challenge for medical scientists worldwide, leading to a number of research efforts that focus on biosensor development for AD biomarkers. However, the application of these complicated biosensors is limited in medical diagnosis, due to the difficulties in robust sensing platform development, high costs, and the necessity for technical professionals. We successfully developed a robust straightforward manufacturing process for the fabrication of multi-chamber paper devices using the wax printing method and exploited it to detect amyloid beta 42 oligomers (AβO42, a significant biomarker of AD) using copper-enhanced gold nanoprobe colorimetric immunoblotting. Small hydrophilic reaction chambers could concentrate the target sample to the desired size to improve the sensing performance. The copper-enhanced gold nanoprobe immunoblot using the designed multi-chamber platform exhibited a highly sensitive performance with a limit of detection of 320 pg/mL by the naked eye and 23.7 pg/mL by a smartphone camera. This process from sensing manufacture to sensing conduction is simple to perform whenever medical technicians require time- and cost-savings, without complicated instruments or the need for technical professionals, making it feasible to serve as a diagnostic tool worldwide for the early monitoring of AD and scalable devices for the sensing application of various biomarkers in clinical settings.

scholarly journals Analysis of anticoagulants for blood-based quantitation of amyloid β oligomers in the sFIDA assay

2017 ◽  
Vol 398 (4) ◽  
pp. 465-475 ◽  
Author(s):  
Kateryna Kravchenko ◽  
Andreas Kulawik ◽  
Maren Hülsemann ◽  
Katja Kühbach ◽  
Christian Zafiu ◽  
...  
Keyword(s):  
Blood Plasma ◽  
Limit Of Detection ◽  
Amyloid Β ◽  
Distribution Analysis ◽  
Aβ Oligomers ◽  
Quantitative Measurements ◽  
Suitable Parameter ◽  
Edta Plasma ◽  
Soluble Aβ Oligomers ◽  
Parameter Values

Abstract Early diagnostics at the preclinical stage of Alzheimer’s disease is of utmost importance for drug development in clinical trials and prognostic guidance. Since soluble Aβ oligomers are considered to play a crucial role in the disease pathogenesis, several methods aim to quantify Aβ oligomers in body fluids such as cerebrospinal fluid (CSF) and blood plasma. The highly specific and sensitive method surface-based fluorescence intensity distribution analysis (sFIDA) has successfully been established for oligomer quantitation in CSF samples. In our study, we explored the sFIDA method for quantitative measurements of synthetic Aβ particles in blood plasma. For this purpose, EDTA-, citrate- and heparin-treated blood plasma samples from five individual donors were spiked with Aβ coated silica nanoparticles (Aβ-SiNaPs) and were applied to the sFIDA assay. Based on the assay parameters linearity, coefficient of variation and limit of detection, we found that EDTA plasma yields the most suitable parameter values for quantitation of Aβ oligomers in sFIDA assay with a limit of detection of 16 fM.

Thienyl diketopyrrolopyrrole as a robust sensing platform for multiple ions and its application in molecular logic system

2017 ◽  
Vol 244 ◽  
pp. 849-853 ◽  
Author(s):  
Kaixuan Nie ◽  
Bo Dong ◽  
Huanhuan Shi ◽  
Zhengchun Liu ◽  
Bo Liang
Keyword(s):  
Molecular Logic ◽  
Sensing Platform ◽  
Robust Sensing ◽  
Logic System

Core-shell Cu@C@ZIF-8 composite: a high-performance electrode material for electrochemical sensing of nitrite with high selectivity and sensitivity

2021 ◽  
Author(s):  
Feng Gao ◽  
Xiaolong Tu ◽  
Yongfang Yu ◽  
Yansha Gao ◽  
Jin Zou ◽  
...  
Keyword(s):  
High Performance ◽  
High Selectivity ◽  
Limit Of Detection ◽  
Metal Organic Framework ◽  
High Sensitivity ◽  
Electrochemical Sensing ◽  
Core Shell ◽  
Zeolitic Imidazolate Framework ◽  
Sensing Platform ◽  
The Difference

Abstract Herein, an efficient electrochemical sensing platform is proposed for selective and sensitive detection of nitrite on the basis of Cu@C@Zeolitic imidazolate framework-8 (Cu@C@ZIF-8) heterostructure. Core-shell Cu@C@ZIF-8 composite was synthesized by pyrolysis of Cu-metal-organic framework@ZIF-8 (Cu-MOF@ZIF-8) in Ar atmosphere on account of the difference of thermal stability between Cu-MOF and ZIF-8. For the sensing system of Cu@C@ZIF-8, ZIF-8 with proper pore size allows nitrite diffuse through the shell, while big molecules cannot, which ensures high selectivity of the sensor. On the other hand, Cu@C as electrocatalyst promotes the oxidation of nitrite, thereby resulting high sensitivity of the sensor. Accordingly, the Cu@C@ZIF-8 based sensor presents excellent performance for nitrite detection, which achieves a wide linear response range of 0.1 µM to 300.0 µM, and a low limit of detection (LOD) of 0.033 µM. In addition, the Cu@C@ZIF-8 sensor possesses excellent stability and reproducibility, and was employed to quantify nitrite in sausage samples with recoveries of 95.45-104.80%.

Two Orders of Magnitude Improvement in the Detection Limit of Droplet-Based Micro-Magnetofluidics with Planar Hall Effect Sensors

2021 ◽  
Vol 6 (1) ◽  
pp. 47
Author(s):  
Julian Schütt ◽  
Rico Illing ◽  
Oleksii Volkov ◽  
Tobias Kosub ◽  
Pablo Nicolás Granell ◽  
...  
Keyword(s):  
Detection Limit ◽  
Hall Effect ◽  
State Of The Art ◽  
Limit Of Detection ◽  
Research Field ◽  
High Throughput Analysis ◽  
Planar Hall Effect ◽  
Biologically Relevant ◽  
Sensing Platform ◽  
Order Of Magnitude

The detection, manipulation, and tracking of magnetic nanoparticles is of major importance in the fields of biology, biotechnology, and biomedical applications as labels as well as in drug delivery, (bio-)detection, and tissue engineering. In this regard, the trend goes towards improvements of existing state-of-the-art methodologies in the spirit of timesaving, high-throughput analysis at ultra-low volumes. Here, microfluidics offers vast advantages to address these requirements, as it deals with the control and manipulation of liquids in confined microchannels. This conjunction of microfluidics and magnetism, namely micro-magnetofluidics, is a dynamic research field, which requires novel sensor solutions to boost the detection limit of tiny quantities of magnetized objects. We present a sensing strategy relying on planar Hall effect (PHE) sensors in droplet-based micro-magnetofluidics for the detection of a multiphase liquid flow, i.e., superparamagnetic aqueous droplets in an oil carrier phase. The high resolution of the sensor allows the detection of nanoliter-sized superparamagnetic droplets with a concentration of 0.58 mg cm−3, even when they are only biased in a geomagnetic field. The limit of detection can be boosted another order of magnitude, reaching 0.04 mg cm−³ (1.4 million particles in a single 100 nL droplet) when a magnetic field of 5 mT is applied to bias the droplets. With this performance, our sensing platform outperforms the state-of-the-art solutions in droplet-based micro-magnetofluidics by a factor of 100. This allows us to detect ferrofluid droplets in clinically and biologically relevant concentrations, and even in lower concentrations, without the need of externally applied magnetic fields.

scholarly journals A Sensitive and Cost-Effective Chemiluminescence ELISA for Measurement of Amyloid-β 1-42 Peptide in Human Plasma

2020 ◽  
Vol 78 (3) ◽  
pp. 1237-1244
Author(s):  
Pankaj D. Mehta ◽  
Bruce A. Patrick ◽  
David L. Miller ◽  
Patricia K. Coyle ◽  
Thomas Wisniewski
Keyword(s):  
Human Plasma ◽  
Single Molecule ◽  
Limit Of Detection ◽  
Sandwich Elisa ◽  
Amyloid Β ◽  
Cost Effective ◽  
Measurement Range ◽  
Rabbit Monoclonal Antibody ◽  
Low Levels ◽  
The Brain

Background: Amyloid-β42 (Aβ42) is associated with plaque formation in the brain of patients with Alzheimer’s disease (AD). Studies have suggested the potential utility of plasma Aβ42 levels in the diagnosis, and in longitudinal study of AD pathology. Conventional ELISAs are used to measure Aβ42 levels in plasma but are not sensitive enough to quantitate low levels. Although ultrasensitive assays like single molecule array or immunoprecipitation-mass spectrometry have been developed to quantitate plasma Aβ42 levels, the high cost of instruments and reagents limit their use. Objective: We hypothesized that a sensitive and cost-effective chemiluminescence (CL) immunoassay could be developed to detect low Aβ42 levels in human plasma. Methods: We developed a sandwich ELISA using high affinity rabbit monoclonal antibody specific to Aβ42. The sensitivity of the assay was increased using CL substrate to quantitate low levels of Aβ42 in plasma. We examined the levels in plasma from 13 AD, 25 Down syndrome (DS), and 50 elderly controls. Results: The measurement range of the assay was 0.25 to 500 pg/ml. The limit of detection was 1 pg/ml. All AD, DS, and 45 of 50 control plasma showed measurable Aβ42 levels. Conclusion: This assay detects low levels of Aβ42 in plasma and does not need any expensive equipment or reagents. It offers a preferred alternative to ultrasensitive assays. Since the antibodies, peptide, and substrate are commercially available, the assay is well suited for academic or diagnostic laboratories, and has a potential for the diagnosis of AD or in clinical trials.

scholarly journals Impedance Sensing Platform for Detection of the Food Pathogen Listeria monocytogenes

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 347 ◽  
Author(s):  
Maria Chiriacò ◽  
Ilaria Parlangeli ◽  
Fausto Sirsi ◽  
Palmiro Poltronieri ◽  
Elisabetta Primiceri
Keyword(s):  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Foodborne Pathogen ◽  
High Sensitivity ◽  
Primary Objective ◽  
Field Application ◽  
Impedance Sensing ◽  
Sensing Platform

A great improvement in food safety and quality controls worldwide has been achieved through the development of biosensing platforms. Foodborne pathogens continue to cause serious outbreaks, due to the ingestion of contaminated food. The development of new, sensitive, portable, high-throughput, and automated platforms is a primary objective to allow detection of pathogens and their toxins in foods. Listeria monocytogenes is one common foodborne pathogen. Major outbreaks of listeriosis have been caused by a variety of foods, including milk, soft cheeses, meat, fermented sausages, poultry, seafood and vegetable products. Due to its high sensitivity and easy setup, electrochemical impedance spectroscopy (EIS) has been extensively applied for biosensor fabrication and in particular in the field of microbiology as a mean to detect and quantify foodborne bacteria. Here we describe a miniaturized, portable EIS platform consisting of a microfluidic device with EIS sensors for the detection of L. monocytogenes in milk samples, connected to a portable impedance analyzer for on-field application in clinical and food diagnostics, but also for biosecurity purposes. To achieve this goal microelectrodes were functionalized with antibodies specific for L. monocytogenes. The binding and detection of L. monocytogenes was achieved in the range 2.2 × 103 cfu/mL to 1 × 102 with a Limit of Detection (LoD) of 5.5 cfu/mL.

scholarly journals Dissolved Carbon Dioxide Sensing Platform for Freshwater and Saline Water Applications: Characterization and Validation in Aquaculture Environments

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5513
Author(s):  
J.P. Mendes ◽  
L. Coelho ◽  
B. Kovacs ◽  
J.M.M.M. de Almeida ◽  
C.M. Pereira ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Limit Of Detection ◽  
Saline Water ◽  
Light Emitting Diode ◽  
Limit Of Quantification ◽  
Acid Media ◽  
Dissolved Carbon ◽  
Sensing Platform ◽  
Dissolved Carbon Dioxide ◽  
Colorimetric Indicator

A sensing configuration for the real-time monitoring, detection, and quantification of dissolved carbon dioxide (dCO2) was developed for aquaculture and other applications in freshwater and saline water. A chemical sensing membrane, based on a colorimetric indicator, is combined with multimode optical fiber and a dual wavelength light-emitting diode (LED) to measure the dCO2-induced absorbance changes in a self-referenced ratiometric scheme. The detection and processing were achieved with an embeded solution having a mini spectrometer and microcontroller. For optrode calibration, chemical standard solutions using sodium carbonate in acid media were used. Preliminary results in a laboratory environment showed sensitivity for small added amounts of CO2 (0.25 mg·L−1). Accuracy and response time were not affected by the type of solution, while precision was affected by salinity. Calibration in freshwater showed a limit of detection (LOD) and a limit of quantification (LOQ) of 1.23 and 1.87 mg·L−1, respectively. Results in saline water (2.5%) showed a LOD and LOQ of 1.05 and 1.16 mg·L−1, respectively. Generally, performance was improved when moving from fresh to saline water. Studies on the dynamics of dissolved CO2 in a recirculating shallow raceway system (SRS+RAS) prototype showed higher precision than the tested commercial sensor. The new sensor is a compact and robust device, and unlike other sensors used in aquaculture, stirring is not required for correct and fast detection. Tests performed showed that this new sensor has a fast accurate detection as well as a strong potential for assessing dCO2 dynamics in aquaculture applications.

scholarly journals Dynamic single-molecule sensing via nanoparticle micromanipulation for rapid and ultrasensitive biomarker detection

2021 ◽  
Author(s):  
Qiang Zeng ◽  
Xiaoyan Zhou ◽  
Yuting Yang ◽  
Yi Sun ◽  
Jingan Wang ◽  
...  
Keyword(s):  
Single Molecule ◽  
Limit Of Detection ◽  
Direct Detection ◽  
Specific Binding ◽  
Single Molecules ◽  
Amyloid Β ◽  
Molecular Complexes ◽  
Biomarker Detection ◽  
Complex Samples ◽  
Practical Applications

Abstract The ability to measure many single molecules simultaneously in larger and complex samples is critical to the translation of single-molecule sensors for practical applications in biomarker detection. The challenges lie in the limits imposed by mass transportation and thermodynamics, resulting in long assay time and/or insufficient sensitivity. Here, we report an approach called Sensing Single Molecule under MicroManipulation (SSM3) to circumvent the above limits. In SSM3, the transportation rate of analyte molecules and the kinetics of molecular interaction are fine-tuned by the nanoparticle micromanipulation. The heterogeneous lifetime of molecular complexes is quantified to discriminate specific binding from nonspecific background noise. By the highly-specific digital counting of single molecules, we demonstrate 15-minute assays for direct detection of microRNAs and amyloid-β proteins via electrical or magnetic micromanipulation, with the limit of detection at the subfemtomolar level. The presented approach could inspire more practical applications of single molecule sensors.

scholarly journals Development of a Cost-Effective Sensing Platform for Monitoring Phosphate in Natural Waters

Chemosensors ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 57 ◽  
Author(s):  
Andrew Donohoe ◽  
Gareth Lacour ◽  
Peter McCluskey ◽  
Dermot Diamond ◽  
Margaret McCaul
Keyword(s):  
Natural Waters ◽  
Limit Of Detection ◽  
Low Cost ◽  
Unit Cost ◽  
High Standard ◽  
Cost Effective ◽  
Remote Access ◽  
Sampling Location ◽  
Sensing Platform

A sensing platform for the in situ, real-time analysis of phosphate in natural waters has been realised using a combination of microfluidics, colorimetric reagent chemistries, low-cost LED-based optical detection and wireless communications. Prior to field deployment, the platform was tested over a period of 55 days in the laboratory during which a total of 2682 autonomous measurements were performed (854 each of sample, high standard and baseline, and 40 × 3 spiked solution measurements). The platform was subsequently field-deployed in a freshwater stream at Lough Rea, Co., Galway, Ireland, to track changes in phosphate over a five day period. During this deployment, 165 autonomous measurements (55 each of sample, high standard, and baseline) were performed and transmitted via general packet radio service (GPRS) to a web interface for remote access. Increases in phosphate levels at the sampling location coincident with rainfall events (min 1.45 µM to max 10.24 µM) were detected during the deployment. The response was found to be linear up to 50 µM PO43−, with a lower limit of detection (LOD) of 0.09 µM. Laboratory and field data suggest that despite the complexity of reagent-based analysers, they are reasonably reliable in remote operation, and offer the best opportunity to provide enhanced in situ chemical sensing capabilities. Modifications that could further improve the reliability and scalability of these platforms while simultaneously reducing the unit cost are discussed.

scholarly journals Aptamer Conformation Switching-Induced Two-Stage Amplification for Fluorescent Detection of Proteins

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 77 ◽  
Author(s):  
Qiao Yu ◽  
Fenfen Zhai ◽  
Hong Zhou ◽  
Zonghua Wang
Keyword(s):  
Molecular Beacon ◽  
Limit Of Detection ◽  
Low Cost ◽  
Dna Aptamer ◽  
Fluorescent Detection ◽  
Fluorescence Signal ◽  
Sensing Platform ◽  
Low Concentrations ◽  
Diagnostic Applications ◽  
Recycling Amplification

Basing on the conformation change of aptamer caused by proteins, a simple and sensitive protein fluorescent assay strategy is proposed, which is assisted by the isothermal amplification reaction of polymerase and nicking endonuclease. In the presence of platelet-derived growth factor (PDGF-BB), the natural conformation of a DNA aptamer would change into a Y-shaped complex, which could hybridize with a molecular beacon (MB) and form a DNA duplex, leading to the open state of the MB and generating a fluorescence signal. Subsequently, with further assistance of isothermal recycling amplification strategies, the designed aptamer sensing platform showed an increment of fluorescence. As a benefit of this amplified strategy, the limit of detection (LOD) was lowered to 0.74 ng/mL, which is much lower than previous reports. This strategy not only offers a new simple, specific, and efficient platform to quantify the target protein in low concentrations, but also shows a powerful approach without multiple washing steps, as well as a precious implementation that has the potential to be integrated into portable, low-cost, and simplified devices for diagnostic applications.

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