A highly sensitive fluorescent sensor based on small molecules doped in electrospun nanofibers: detection of explosives as well as color modulation

A new type of highly sensitive low-cost sensor towards nitro-compounds based on PEO/MePyCz composite nanofibers is reported. The composite nanomaterials may also be applied in nano-optoelectronics devices, light-emitting diodes or biological sensors.

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Driving force to detect Alzheimer's disease biomarkers: application of a thioflavine T@Er-MOF ratiometric fluorescent sensor for smart detection of presenilin 1, amyloid β-protein and acetylcholine

The Analyst ◽

10.1039/d0an00440e ◽

2020 ◽

Vol 145 (13) ◽

pp. 4646-4663

Author(s):

Xing Ze Wang ◽

Jing Du ◽

Nan Nan Xiao ◽

Yan Zhang ◽

Ling Fei ◽

...

Keyword(s):

Driving Force ◽

Fluorescent Sensor ◽

Low Cost ◽

Amyloid Β ◽

Amyloid Β Protein ◽

Disease Biomarkers ◽

Β Protein ◽

Highly Sensitive ◽

Highly Sensitive Detection ◽

Detection Strategies

ThT@Er-MOF has been successfully applied in highly sensitive detection of three main Alzheimer Disease biomarkers through three different low cost and facile detection strategies.

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Transparent Ultraviolet Photodetectors Based on Ga2O3 Electrospun Nanowires

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.281.710 ◽

2018 ◽

Vol 281 ◽

pp. 710-715

Author(s):

Muhammad Shahid ◽

Tian Jun Li ◽

Meng Fei Zhang ◽

Jing Cheng ◽

Yan Xing ◽

...

Keyword(s):

Uv Light ◽

Low Cost ◽

Electrospun Nanofibers ◽

High Transparency ◽

Highly Sensitive ◽

Electrospinning Method ◽

Low Dimensional ◽

Ultraviolet Photodetectors ◽

High Photosensitivity ◽

Excellent Stability

Ultraviolet photodetectors (PDs) based on low-dimensional (LD) gallium oxide nanofibers were synthesized and assembled by a low cost and scalable electrospinning method. Highly uniaxially aligned nanofibers were used to assemble photodetectors. Photoconductive investigations indicate that the prepared photodetectors (PDs) are highly sensitive to ultraviolet (UV) light. The prepared photodetectors have shown a high photosensitivity (103), fast photoresponse, excellent stability, and reproducibility under the illumination of UV light 254 nm. These electrospun nanofibers have also shown a high transparency (<85%) in the visible light 400-700 nm range. The high transparency of these nanobelts demonstrates their use for invisible UV photosensors.

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Label-Free Fluorescent Aptasensor for Small Targets via Displacement of Groove Bound Curcumin Molecules

Sensors ◽

10.3390/s19194181 ◽

2019 ◽

Vol 19 (19) ◽

pp. 4181 ◽

Cited By ~ 3

Author(s):

Baraa J. Alyamani ◽

Omar A. Alsager ◽

Mohammed Zourob

Keyword(s):

Small Molecules ◽

Dynamic Range ◽

Fluorescent Sensor ◽

Low Cost ◽

High Sensitivity ◽

Synthetic Dyes ◽

Label Free ◽

Target Molecule ◽

Small Targets ◽

Aptamer Sequence

Signal transduction based on fluorescence is one of the most common optical aptasensors for small molecules. Sensors with a number of unique features including high sensitivity, low cost, and simple operation can be constructed easily. However, the label-free fluorescent approach is limited to synthetic dyes that bind strongly to the aptamer sequence and result in a diminished sensor operation with high detection limits. In this study, we report the use of curcumin as a fluorescent probe to signal aptamer/small target binding events. A substantial enhancement in curcumin’s fluorescent emission was observed when bound into the grooves of vitamin D3 (VTD3) binding aptamer, as an example. However, the introduction of the target molecule causes the aptamer to undergo a conformational change that favors complexing the target molecule over binding the curcumin dye. The sensor was able to detect VTD3 down to 1 fM concentration in buffer solutions and extracted blood samples, operate at a wide dynamic range, and discriminate against potential biological interfering molecules including VTD2. The operation of the curcumin based fluorescent sensor is at least six orders of magnitude more sensitive than a VTD3 sensor constructed with the synthetic dye SYBR Green I. The generality of the reported label-free approach was applied with a previously isolated 75-mer bisphenol-A (BPA) aptamer, confirming that the reported sensing strategy is not confined on a particular aptamer sequence. Our work not only reports a novel sensor format for the detection of small molecules, but also serves fluorescent sensor’s most pressing need being novel fluorophores for multiplex targets detection.

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A Highly Sensitive Fluorescent Sensor for Amitrole Determination in Aqueous Samples

NANO ◽

10.1142/s1793292017500710 ◽

2017 ◽

Vol 12 (07) ◽

pp. 1750071

Author(s):

Yue Wang ◽

Danqun Huo ◽

Jingzhou Hou ◽

Junjie Li ◽

Mei Yang ◽

...

Keyword(s):

Fluorescent Sensor ◽

Low Cost ◽

High Sensitivity ◽

Inner Filter Effect ◽

Aqueous Samples ◽

Cdte Qds ◽

Sensor Platform ◽

Highly Sensitive ◽

Wide Range ◽

Optimized Conditions

A simple yet sensitive fluorescent sensor was reported for amitrole analysis based on integration of gold nanoparticles (AuNPs) and CdTe quantum dots (CdTe QDs) via inner filter effect (IFE). The fluorescence of GSH-coated CdTe QDs can be significantly quenched by AuNPs, and gradually restored in the presence of amitrole. Addition of amitrole induced AuNPs aggregation and decreased their characteristic surface plasmon absorption, which diminished the IFE between them. The sensor platform realized high sensitivity and good reproducibility in low concentration amitrole ranging from 9.5[Formula: see text]nM to 1000[Formula: see text]nM with a detection limit down to 4.75[Formula: see text]nM under the optimized conditions. It also resisted a wide range of interfering counterparts and showed analytical performance comparable to the majority of analytical methods reported in prior studies. We envisioned the first fluorescent amitrole sensor would be potentially useful for low cost on-site amitrole monitoring in real application.

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A rapid, accurate, scalable, and portable testing system for COVID-19 diagnosis

Nature Communications ◽

10.1038/s41467-021-23185-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Guanhua Xun ◽

Stephan Thomas Lane ◽

Vassily Andrew Petrov ◽

Brandon Elliott Pepa ◽

Huimin Zhao

Keyword(s):

Limit Of Detection ◽

Low Cost ◽

High Volume ◽

N Gene ◽

Testing System ◽

Target Sequence ◽

One Pot ◽

Sequence Detection ◽

Highly Sensitive ◽

Speed Accuracy

AbstractThe need for rapid, accurate, and scalable testing systems for COVID-19 diagnosis is clear and urgent. Here, we report a rapid Scalable and Portable Testing (SPOT) system consisting of a rapid, highly sensitive, and accurate assay and a battery-powered portable device for COVID-19 diagnosis. The SPOT assay comprises a one-pot reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) followed by PfAgo-based target sequence detection. It is capable of detecting the N gene and E gene in a multiplexed reaction with the limit of detection (LoD) of 0.44 copies/μL and 1.09 copies/μL, respectively, in SARS-CoV-2 virus-spiked saliva samples within 30 min. Moreover, the SPOT system is used to analyze 104 clinical saliva samples and identified 28/30 (93.3% sensitivity) SARS-CoV-2 positive samples (100% sensitivity if LoD is considered) and 73/74 (98.6% specificity) SARS-CoV-2 negative samples. This combination of speed, accuracy, sensitivity, and portability will enable high-volume, low-cost access to areas in need of urgent COVID-19 testing capabilities.

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Recent Advances in Quenchbody, a Fluorescent Immunosensor

Sensors ◽

10.3390/s21041223 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1223

Author(s):

Jinhua Dong ◽

Hiroshi Ueda

Keyword(s):

Fluorescence Intensity ◽

Fluorescent Dyes ◽

Antibody Fragment ◽

Disease Diagnosis ◽

Disease Biomarkers ◽

Highly Sensitive ◽

Physiologically Active Substances ◽

New Type ◽

Antigen Antibody ◽

Active Substances

The detection of viruses, disease biomarkers, physiologically active substances, drugs, and chemicals is of great significance in many areas of our lives. Immunodetection technology is based on the specificity and affinity of antigen–antibody reactions. Compared with other analytical methods such as liquid chromatography coupled with mass spectrometry, which requires a large and expensive instrument, immunodetection has the advantages of simplicity and good selectivity and is thus widely used in disease diagnosis and food/environmental monitoring. Quenchbody (Q-body), a new type of fluorescent immunosensor, is an antibody fragment labeled with fluorescent dyes. When the Q-body binds to its antigen, the fluorescence intensity increases. The detection of antigens by changes in fluorescence intensity is simple, easy to operate, and highly sensitive. This review comprehensively discusses the principle, construction, application, and current progress related to Q-bodies.

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Immobilization of Pseudomonas aeruginosa static biomass on eggshell powder for on-line preconcentration and determination of Cr (VI)

Open Chemistry ◽

10.1515/chem-2020-0031 ◽

2020 ◽

Vol 18 (1) ◽

pp. 303-313 ◽

Cited By ~ 1

Author(s):

Aamir Rasheed ◽

Tahseen Ghous ◽

Sumaira Mumtaz ◽

Muhammad Nadeem Zafar ◽

Kalsoom Akhter ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Low Cost ◽

Colorimetric Detection ◽

Time Flow ◽

Highly Sensitive ◽

Glass Column ◽

On Line ◽

Preconcentration Time ◽

Ultra Trace

AbstractIn the present work, a novel continuous flow system (CFS) is developed for the preconcentration and determination of Cr (VI) using Pseudomonas aeruginosa static biomass immobilized onto an effective and low-cost solid support of powdered eggshells. A mini glass column packed with the immobilized biosorbent is incorporated in a CFS for the preconcentration and determination of Cr (VI) from aqueous solutions. The method is based on preconcentration, washing and elution steps followed by colorimetric detection with 1,5-diphenyl carbazide in sulphuric acid. The effects of several variables such as pH, retention time, flow rate, eluent concentration and loaded volume are studied. Under optimal conditions, the CFS method has a linear range between 10 and 100 μg L-1 and a detection limit of 6.25 μg L-1 for the determination of Cr (VI). The sampling frequency is 10 samples per hour with a preconcentration time of 5 mins. Furthermore, after washing with a 0.1 M buffer (pH 3.0), the activity of the biosorbent is regenerated and remained comparable for more than 200 cycles. Scanning electron microscopy reveals a successful immobilization of biomass on eggshells powder and precipitation of Cr (VI) on the bacterial cell surface. The proposed method proves highly sensitive and could be suitable for the determination of Cr (VI) at an ultra-trace level.

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