scholarly journals The Fabrication of Amino Acid Incorporated Nanoflowers with Intrinsic Peroxidase-like Activity and Its Application for Efficiently Determining Glutathione with TMB Radical Cation as Indicator

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1099
Author(s):  
Ning Jiang ◽  
Chuang Zhang ◽  
Meng Li ◽  
Shuai Li ◽  
Zhili Hao ◽  
...  
Keyword(s):  
Amino Acid ◽  
High Selectivity ◽  
Storage Stability ◽  
Mechanical Stability ◽  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Detection System ◽  
High Sensitivity ◽  
Peroxidase Mimics ◽  
Application Potential

The assessment of glutathione (GSH) levels is associated with early diagnostics and pathological analysis for various disorders. Among all kinds of techniques for detecting GSH, the colorimetric assay relying on the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) catalyzed by many nanomaterials with peroxidase-like activity attracts increasing attention owing to its outstanding merits, such as high sensitivity and high selectivity. However, the aggregation between the nanomaterials severely hinders the entrance of TMB into the “active site” of these peroxidase mimics. To address this problem, the D-amino acid incorporated nanoflowers possessing peroxidase-like activity with a diameter of 10–15 μm, TMB and H2O2 were employed to establish the detection system for determining the level of glutathione. The larger diameter size of the hybrid nanoflowers substantially averts the aggregation between them. The results confirm that the hybrid nanoflowers detection system presents a low limit of detection, wide linear range, perfect selectivity, good storage stability and desired operational stability for the detection of GSH relying on the intrinsic peroxidase-like activity and favorable mechanical stability of the hybrid nanoflowers, indicating that the hybrid nanoflowers detection system has tremendous application potential in clinical diagnosis and treatment.

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%.

scholarly journals Exploiting a new europium(III) coordination polymer based on a zwitterionic ligand as a fluorescent probe for uranyl cations

2020 ◽  
pp. 174751982093226
Author(s):  
Bin Cai ◽  
Yu-Ning Meng ◽  
Meng-En Zhu ◽  
Youming Yang
Keyword(s):  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Coordination Polymer ◽  
High Selectivity ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Fast Response ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray

Two new isostructural lanthanide(III) coordination polymers based on an unreported zwitterionic ligand, namely, [Ln(ox)(L)]n (ox = oxalate, HL = N,N'-dipropionic acid imidazolium, Ln = Eu or La), are synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analysis. The fluorescence properties of the europium coordination polymer are investigated. In addition, the europium-based coordination polymer is utilized for specific sensing of UO22+ ions, showing high selectivity, a fast response time (8 min) and high sensitivity with noticeable quenching ( Ksv = 6.19 × 104 M−1) and limit of detection of 1.95 µM.

A chip-based potentiometric sensor for a Zika virus diagnostic using 3D surface molecular imprinting

The Analyst ◽  
2019 ◽  
Vol 144 (14) ◽  
pp. 4266-4280 ◽  
Author(s):  
Vincent Ricotta ◽  
Yingjie Yu ◽  
Nicholas Clayton ◽  
Ya-Chen Chuang ◽  
Yantian Wang ◽  
...  
Keyword(s):  
Molecular Imprinting ◽  
Zika Virus ◽  
High Selectivity ◽  
Detection System ◽  
Point Of Care ◽  
Lab On A Chip ◽  
High Sensitivity ◽  
Potentiometric Sensor ◽  
Surface Molecular Imprinting ◽  
3D Surface

The high sensitivity and high selectivity demonstrated here proved that this lab-on-a-chip diagnostic has the potential to become a point-of-care (POC) detection system for rapid and accurate screening of flaviviruses.

scholarly journals Sensing Techniques for Organochlorides through Intermolecular Interaction with Bicyclic Amidines

Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 413
Author(s):  
Jong-Won Park ◽  
Lee-Woon Jang ◽  
Erik C. Jensen ◽  
Amanda Stockton ◽  
Jungkyu Kim
Keyword(s):  
Environmental Protection Agency ◽  
Limit Of Detection ◽  
Direct Detection ◽  
Colorimetric Assay ◽  
High Sensitivity ◽  
The United States ◽  
Detection Sensitivity ◽  
Detection Mechanism ◽  
Sensing Platform ◽  
High Volatility

Toxic organochloride molecules are widely used in industry for various purposes. With their high volatility, the direct detection of organochlorides in environmental samples is challenging. Here, a new organochloride detection mechanism using 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) is introduced to simplify a sensing method with higher detection sensitivity. Three types of organochloride compounds-trichloroethylene (TCE), dichloromethane (DCM), and dichlorodiphenyltrichloroethane (DDT)—were targeted to understand DCM conjugation chemistry by using nuclear magnetic resonance (NMR) and liquid chromatography with a mass spectrometer (LC-MS). 13C-NMR spectra and LC-MS data indicated that DBN can be labeled on these organochloride compounds by chlorine–nitrogen interaction. Furthermore, to demonstrate the organochloride sensing capability, the labeling yield and limit of detection were determined by a colorimetric assay as well as micellar electrokinetic chromatography (MEKC). The interaction with DBN was most appreciable for TCE, among other organochlorides. TCE was detected at picomolar levels, which is two orders of magnitude lower than the maximum contaminant level set by the United States Environmental Protection Agency. MEKC, in conjunction with this DBN-labeling method, enables us to develop a field-deployable sensing platform for detecting toxic organochlorides with high sensitivity.

Giant Magnetoresistive Based Handheld System for Rapid Detection of Human NT-proBNP

2019 ◽  
Author(s):  
Wei Wang ◽  
Todd Klein ◽  
James Collins
Keyword(s):  
Limit Of Detection ◽  
Detection System ◽  
Point Of Care ◽  
High Sensitivity ◽  
Time Signal ◽  
Point Of Care Testing ◽  
Detection Range ◽  
Further Development ◽  
Signal Readout

In this work, we developed giant magnetoresistive (GMR) based handheld biosensing systems that serve as platform for detecting human NT-proBNP. This assay takes advantages of high sensitivity and real-time signal readout of GMR biosensor. The limit of detection was estimated to be less than 0.01ng/mL, and detection range covered from 0.01 ng/mL to 5 ng/mL was obtained. The assay can be completed within 20 min, which is very important for further development of point-of-care testing. The proposed GMR handheld system is also successfully used for the detection of real NT-proBNP human samples. It can be foreseen that this handheld detection system could become a robust contender in the applications of in vitro biomarker diagnostics.

scholarly journals Detection of Mercury Ion with High Sensitivity and Selectivity Using a DNA/Graphene Oxide Hybrid Immobilized on Glass Slides

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 300
Author(s):  
Li Gao ◽  
Qiuxiang Lv ◽  
Ni Xia ◽  
Yuanwei Lin ◽  
Feng Lin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
High Selectivity ◽  
Limit Of Detection ◽  
Low Cost ◽  
High Sensitivity ◽  
Mercury Ions ◽  
Research Areas ◽  
Glass Slides ◽  
Highly Sensitive ◽  
Sensitivity And Selectivity

Excessive mercury ions (Hg2+) cause great pollution to soil/water and pose a major threat to human health. The high sensitivity and high selectivity in the Hg2+ detection demonstrated herein are significant for the research areas of analytical chemistry, chemical biology, physical chemistry, drug discovery, and clinical diagnosis. In this study, a series of simple, low-cost, and highly sensitive biochips based on a graphene oxide (GO)/DNA hybrid was developed. Hg2+ is detected with high sensitivity and selectivity by GO/DNA hybrid biochips immobilized on glass slides. The performance of the biosensors can be improved by introducing more phosphorothioate sites and complementary bases. The best limit of detection of the biochips is 0.38 nM with selectivity of over 10:1. This sensor was also used for Hg2+ detection in Dendrobium. The results show this biochip is promising for Hg2+ detection.

scholarly journals A Graphene Oxide–Based Sensing Platform for the Determination of Methicillin-Resistant Staphylococcus aureus Based on Strand-Displacement Polymerization Recycling and Synchronous Fluorescent Signal Amplification

2016 ◽  
Vol 21 (8) ◽  
pp. 851-857 ◽  
Author(s):  
Yi Ning ◽  
Qiang Gao ◽  
Xiaoqing Zhang ◽  
Ke Wei ◽  
Lingli Chen
Keyword(s):  
Staphylococcus Aureus ◽  
Graphene Oxide ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Limit Of Detection ◽  
Detection System ◽  
Meca Gene ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Klenow Fragment ◽  
Methicillin Resistant

To develop new technology for detecting methicillin-resistant Staphylococcus aureus (MRSA), a novel fluorescent biosensor based on Klenow fragment (KF)–assisted target recycling amplification and synchronous fluorescence analysis was created. Carboxy-fluorescein (FAM)–labeled single-stranded DNA (ssDNA) containing a capture probe and a signal probe was adsorbed onto the surface of graphene oxide (GO) via π-stacking interactions, resulting in the fluorescence quenching of the dye. When target and primer were introduced, the fluorescence was restored due to P0 being completely released from the surface of the GO. Meanwhile, by using the KF and exploiting the synergistic effect of FAM and the double-stranded DNA (dsDNA)–SYBR Green I duplex structure, the fluorescence in this detection system was considerably amplified and the sensitivity was improved. The proposed strategy for mecA gene analysis showed a good linear range from 1 to 40 nmol/L, with a lower limit of detection of 0.5 nmol/L. In addition, a bacterial sample harboring the mecA gene was also detected, and its lower detection limit was up to 300 colony-forming units (CFU)/mL. Accordingly, this biosensor exhibits high sensitivity and selectivity and has great potential for early clinical diagnosis and treatment.

scholarly journals Validation of a Novel Diagnostic Approach Combining the VersaTREK™ System for Recovery and Real-Time PCR for the Identification of Mycobacterium chimaera in Water Samples

2021 ◽  
Vol 9 (5) ◽  
pp. 1031
Author(s):  
Roberto Zoccola ◽  
Alessia Di Blasio ◽  
Tiziana Bossotto ◽  
Angela Pontei ◽  
Maria Angelillo ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Limit Of Detection ◽  
Detection System ◽  
Bacterial Load ◽  
Microbial Control ◽  
Hospital Setting ◽  
Sample Volume ◽  
Analytical Sensitivity ◽  
Initial Water

Mycobacterium chimaera is an emerging pathogen associated with endocarditis and vasculitis following cardiac surgery. Although it can take up to 6–8 weeks to culture on selective solid media, culture-based detection remains the gold standard for diagnosis, so more rapid methods are urgently needed. For the present study, we processed environmental M. chimaera infected simulates at volumes defined in international guidelines. Each preparation underwent real-time PCR; inoculates were placed in a VersaTREK™ automated microbial detection system and onto selective Middlebrook 7H11 agar plates. The validation tests showed that real-time PCR detected DNA up to a concentration of 10 ng/µL. A comparison of the isolation tests showed that the PCR method detected DNA in a dilution of ×102 CFU/mL in the bacterial suspensions, whereas the limit of detection in the VersaTREK™ was <10 CFU/mL. Within less than 3 days, the VersaTREK™ detected an initial bacterial load of 100 CFU. The detection limit did not seem to be influenced by NaOH decontamination or the initial water sample volume; analytical sensitivity was 1.5 × 102 CFU/mL; positivity was determined in under 15 days. VersaTREK™ can expedite mycobacterial growth in a culture. When combined with PCR, it can increase the overall recovery of mycobacteria in environmental samples, making it potentially applicable for microbial control in the hospital setting and also in environments with low levels of contamination by viable mycobacteria.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

scholarly journals A Compact Detection Platform Based on Gradient Guided-Mode Resonance for Colorimetric and Fluorescence Liquid Assay Detection

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2797
Author(s):  
Jing-Jhong Gao ◽  
Ching-Wei Chiu ◽  
Kuo-Hsing Wen ◽  
Cheng-Sheng Huang
Keyword(s):  
Limit Of Detection ◽  
Detection System ◽  
Fluorescence Emission ◽  
Assay Sensitivity ◽  
Detection Range ◽  
Current Form ◽  
Guided Mode ◽  
Spectral Detection ◽  
Guided Mode Resonance ◽  
Colorimetric Assays

This paper presents a compact spectral detection system for common fluorescent and colorimetric assays. This system includes a gradient grating period guided-mode resonance (GGP-GMR) filter and charge-coupled device. In its current form, the GGP-GMR filter, which has a size of less than 2.5 mm, can achieve a spectral detection range of 500–700 nm. Through the direct measurement of the fluorescence emission, the proposed system was demonstrated to detect both the peak wavelength and its corresponding intensity. One fluorescent assay (albumin) and two colorimetric assays (albumin and creatinine) were performed to demonstrate the practical application of the proposed system for quantifying common liquid assays. The results of our system exhibited suitable agreement with those of a commercial spectrometer in terms of the assay sensitivity and limit of detection (LOD). With the proposed system, the fluorescent albumin, colorimetric albumin, and colorimetric creatinine assays achieved LODs of 40.99 and 398 and 25.49 mg/L, respectively. For a wide selection of biomolecules in point-of-care applications, the spectral detection range achieved by the GGP-GMR filter can be further extended and the simple and compact optical path configuration can be integrated with a lab-on-a-chip system.

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