scholarly journals Development of an Interdigitated Electrode-Based Disposable Enzyme Sensor Strip for Glycated Albumin Measurement

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 734
Author(s):  
Mika Hatada ◽  
Noya Loew ◽  
Junko Okuda-Shimazaki ◽  
Mukund Khanwalker ◽  
Wakako Tsugawa ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Glycated Albumin ◽  
Oxidation Potential ◽  
Interdigitated Electrode ◽  
Enzyme Sensor ◽  
Oxidation Current ◽  
Steady Current ◽  
Protease Digestion ◽  
Highly Sensitive ◽  
Enzyme Sensors

Glycated albumin (GA) is an important glycemic control marker for diabetes mellitus. This study aimed to develop a highly sensitive disposable enzyme sensor strip for GA measurement by using an interdigitated electrode (IDE) as an electrode platform. The superior characteristics of IDE were demonstrated using one microelectrode of the IDE pair as the working electrode (WE) and the other as the counter electrode, and by measuring ferrocyanide/ferricyanide redox couple. The oxidation current was immediately reached at the steady state when the oxidation potential was applied to the WE. Then, an IDE enzyme sensor strip for GA measurement was prepared. The measurement of fructosyl lysine, the protease digestion product of GA, exhibited a high, steady current immediately after potential application, revealing the highly reproducible measurement. The sensitivity (2.8 nA µM−1) and the limit of detection (1.2 µM) obtained with IDE enzyme sensor strip were superior compared with our previously reported sensor using screen printed electrode. Two GA samples, 15 or 30% GA, corresponding to healthy and diabetic levels, respectively, were measured after protease digestion with high resolution. This study demonstrated that the application of an IDE will realize the development of highly sensitive disposable-type amperometric enzyme sensors with high reproducibility.

Detection of Glucose in Human Serum Based on Silicon Dot Probe

2020 ◽  
Vol 16 (6) ◽  
pp. 744-752
Author(s):  
Kuan Luo ◽  
Xinyu Jiang
Keyword(s):  
Quantum Dots ◽  
Blood Glucose ◽  
Human Serum ◽  
Organic Dyes ◽  
Limit Of Detection ◽  
Fasting Blood Glucose ◽  
Glucose Biosensor ◽  
Metal Nanoclusters ◽  
Glucose Levels ◽  
Highly Sensitive

Background: Diabetes Mellitus (DM) is a major public metabolic disease that influences 366 million people in the world in 2011, and this number is predicted to rise to 552 million in 2030. DM is clinically diagnosed by a fasting blood glucose that is equal or greater than 7 mM. Therefore, the development of effective glucose biosensor has attracted extensive attention worldwide. Fluorescence- based strategies have sparked tremendous interest due to their rapid response, facile operation, and excellent sensitivity. Many fluorescent compounds have been employed for precise analysis of glucose, including quantum dots, noble metal nanoclusters, up-converting nanoparticles, organic dyes, and composite fluorescent microspheres. Silicon dot as promising quantum dots materials have received extensive attention, owing to their distinct advantages such as biocompatibility, low toxicity and high photostability. Methods: MnO2 nanosheets on the Si nanoparticles (NPs) surface serve as a quencher. Si NPs fluorescence can make a recovery by the addition of H2O2, which can reduce MnO2 to Mn2+, and the glucose can thus be monitored based on the enzymatic conversion of glucose by glucose oxidase to generate H2O2. Therefore, the glucose concentration can be derived by recording the fluorescence recovery spectra of the Si NPs. Results: This probe enabled selective detection of glucose with a linear range of 1-100 μg/mL and a limit of detection of 0.98 μg/mL. Compared with the commercial glucometer, this method showed favorable results and convincing reliability. Conclusion: We have developed a novel method based on MnO2 -nanosheet-modified Si NPs for rapid monitoring of blood glucose levels. By combining the highly sensitive H2O2/MnO2 reaction with the excellent photostability of Si NPs, a highly sensitive, selective, and cost-efficient sensing approach for glucose detection has been designed and applied to monitor glucose levels in human serum with satisfactory results.

scholarly journals Computational Design of a Molecularly Imprinted Polymer for the Biomonitoring of the Organophosphorous Metabolite Chlorferron

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 192
Author(s):  
Bakhtiyar Qader ◽  
Issam Hussain ◽  
Mark Baron ◽  
Rebeca Jiménez-Pérez ◽  
Guzmán Gil-Ramírez ◽  
...  
Keyword(s):  
Biological Samples ◽  
Limit Of Detection ◽  
Computational Design ◽  
Signal Change ◽  
Highly Sensitive ◽  
Limit Of Quantitation ◽  
Molecularly Imprinting Polymers ◽  
Mip Sensor ◽  
Parasitic Mites

Coumaphos is an organophosphorus compound used as insecticide and frequently used by beekeepers for the management of parasitic mites. The most important metabolite, chlorferron (CFN), has been identified in biological samples and foodstuff. The need to quickly identify the presence of typical metabolites, as an indication of interaction with coumaphos has driven the need to produce a highly sensitive electrochemical method for chlorferron analysis, based on molecularly imprinting polymers (MIP) technology. It showed irreversible behaviour with mixed diffusion/adsorption-controlled reactions at the electrode surface. A monoelectronic mechanism of reaction for oxidation has also been suggested. The linear range observed was from 0.158 to 75 µM. Median precision in terms of %RSD around 3% was also observed. For DPV, the limit of detection (LOD) and the limit of quantitation (LOQ) for the CFN-MIP were 0.158 µM and 0.48 µM, respectively. The obtained median % recovery was around 98%. The results were also validated to reference values obtained using GC-MS. Urine and human synthetic plasma spiked with CFN were used to demonstrate the usability of the method in biological samples, showing the potential for biomonitoring. The developed imprinted sensor showed maximum signal change less than 16.8% when related metabolites or pesticide were added to the mix, suggesting high selectivity of the MIP sensor toward CFN molecules. The results from in vitro metabolism of CMP analysed also demonstrates the potential for detection and quantification of CFN in environmental samples. The newly developed CFN-MIP sensor offers similar LoDs than chromatographic methods with shorter analysis time.

scholarly journals Simultaneous electrochemical sensing of dihydroxy benzene isomers at cost-effective allura red polymeric film modified glassy carbon electrode

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pattan-Siddappa Ganesh ◽  
Ganesh Shimoga ◽  
Seok-Han Lee ◽  
Sang-Youn Kim ◽  
Eno E. Ebenso
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Tap Water ◽  
Differential Pulse ◽  
Oxidation Potential ◽  
Electrochemical Sensing ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Allura Red

Abstract Background A simple and simultaneous electrochemical sensing platform was fabricated by electropolymerization of allura red on glassy carbon electrode (GCE) for the interference-free detection of dihydroxy benzene isomers. Methods The modified working electrode was characterized by electrochemical and field emission scanning electron microscopy methods. The modified electrode showed excellent electrocatalytic activity for the electrooxidation of catechol (CC) and hydroquinone (HQ) at physiological pH of 7.4 by cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. Results The effective split in the overlapped oxidation signal of CC and HQ was achieved in a binary mixture with peak to peak separation of 0.102 V and 0.103 V by CV and DPV techniques. The electrode kinetics was found to be adsorption-controlled. The oxidation potential directly depends on the pH of the buffer solution, and it witnessed the transfer of equal number of protons and electrons in the redox phenomenon. Conclusions The limit of detection (LOD) for CC and HQ was calculated to be 0.126 μM and 0.132 μM in the linear range of 0 to 80.0 μM and 0 to 110.0 μM, respectively, by ultra-sensitive DPV technique. The practical applicability of the proposed sensor was evaluated for tap water sample analysis, and good recovery rates were observed. Graphical abstract Electrocatalytic interaction of ALR/GCE with dihydroxy benzene isomers.

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

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.

scholarly journals Highly sensitive and selective colorimetric detection of dual metal ions (Hg2+ and Sn2+) in water: an eco-friendly approach

RSC Advances ◽  
2021 ◽  
Vol 11 (24) ◽  
pp. 14700-14709
Author(s):  
Rintumoni Paw ◽  
Moushumi Hazarika ◽  
Purna K. Boruah ◽  
Amlan Jyoti Kalita ◽  
Ankur K. Guha ◽  
...  
Keyword(s):  
Metal Ions ◽  
Ag Nanoparticles ◽  
Limit Of Detection ◽  
Colorimetric Detection ◽  
Garlic Extract ◽  
Selective Detection ◽  
Highly Sensitive ◽  
Dual Metal

Synthesis of Ag nanoparticles using Allin based garlic extract for highly sensitive and selective detection of metal ions Hg2+ and Sn2+ in water. The limit of detection (LoD) for Hg2+ and Sn2+ ions were found as 15.7 nM and 11.25 nM respectively.

scholarly journals Immobilization-Free Electrochemical Sensor Coupled with a Graphene-Oxide-Based Aptasensor for Glycated Albumin Detection

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 85
Author(s):  
Wassa Waiwinya ◽  
Thitirat Putnin ◽  
Dechnarong Pimalai ◽  
Wireeya Chawjiraphan ◽  
Nuankanya Sathirapongsasuti ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Detection Method ◽  
Limit Of Detection ◽  
Glycated Albumin ◽  
Cost Effective ◽  
Logarithmic Scale ◽  
Electrochemical Aptasensor ◽  
Alternative Approach

An immobilization-free electrochemical sensor coupled with a graphene oxide (GO)-based aptasensor was developed for glycated human serum albumin (GHSA) detection. The concentration of GHSA was monitored by measuring the electrochemical response of free GO and aptamer-bound GO in the presence of glycated albumin; their currents served as the analytical signals. The electrochemical aptasensor exhibited good performance with a base-10 logarithmic scale. The calibration curve was achieved in the range of 0.01–50 µg/mL. The limit of detection (LOD) was 8.70 ng/mL. The developed method was considered a one-drop measurement process because a fabrication step and the probe-immobilization process were not required. This simple sensor offers a cost-effective, rapid, and sensitive detection method, and could be an alternative approach for determination of GHSA levels.

scholarly journals Multi-Quantum Dots-Embedded Silica-Encapsulated Nanoparticle-Based Lateral Flow Assay for Highly Sensitive Exosome Detection

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 768
Author(s):  
Hyung-Mo Kim ◽  
Chiwoo Oh ◽  
Jaehyun An ◽  
Seungki Baek ◽  
Sungje Bock ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Limit Of Detection ◽  
Specific Binding ◽  
Calf Serum ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Uniform Size ◽  
Highly Sensitive ◽  
Wide Range ◽  
New Biomarkers

Exosomes are attracting attention as new biomarkers for monitoring the diagnosis and prognosis of certain diseases. Colorimetric-based lateral-flow assays have been previously used to detect exosomes, but these have the disadvantage of a high limit of detection. Here, we introduce a new technique to improve exosome detection. In our approach, highly bright multi-quantum dots embedded in silica-encapsulated nanoparticles (M–QD–SNs), which have uniform size and are brighter than single quantum dots, were applied to the lateral flow immunoassay method to sensitively detect exosomes. Anti-CD63 antibodies were introduced on the surface of the M–QD–SNs, and a lateral flow immunoassay with the M–QD–SNs was conducted to detect human foreskin fibroblast (HFF) exosomes. Exosome samples included a wide range of concentrations from 100 to 1000 exosomes/µL, and the detection limit of our newly designed system was 117.94 exosome/μL, which was 11 times lower than the previously reported limits. Additionally, exosomes were selectively detected relative to the negative controls, liposomes, and newborn calf serum, confirming that this method prevented non-specific binding. Thus, our study demonstrates that highly sensitive and quantitative exosome detection can be conducted quickly and accurately by using lateral immunochromatographic analysis with M–QD–SNs.

scholarly journals Gold-nanourchin complexed silicon dioxide-probe on gap-fingered interdigitated electrode surface for Parkinson’s Disease determination by current–volt measurement

2021 ◽  
Vol 11 ◽  
pp. 184798042098735
Author(s):  
Xiaohong Li ◽  
Wei Shi ◽  
Wenyan Zhang ◽  
Weiyao Chen ◽  
Dan Cao ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Silicon Dioxide ◽  
Limit Of Detection ◽  
Detection System ◽  
Interdigitated Electrode ◽  
Limit Of Quantification ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Detection Range

Parkinson’s disease (PD) is a nervous disorder, affects physical movement, and leads to difficulty in balancing, walking, and coordination. A novel sensor is mandatory to determine PD and monitor the progress of the treatment. Neurofilament light chain (NfL) has been recognized as a good biomarker for PD and also helps to distinguish between PD and atypical PD syndromes. Immunosensor was generated by current–volt measurement on gap-fingered interdigitated electrode with silicon dioxide surface to determine NfL level. To enhance the detection, anti-NfL antibody was complexed with gold-nanourchin and immobilized on the sensing electrode. The current–volt response was gradually increased at the linear detection range from 100 fM to 1 nM. Limit of detection and sensitivity were 100 fM with the signal-to-noise ratio at n = 3 on a linear curve ( y = 0.081 x + 1.593; R 2 = 0.9983). Limit of quantification falls at 1 pM and high performance of the sensor was demonstrated by discriminating against other neurogenerative disease markers, in addition, it was reproducible even in serum-spiked samples. This method of detection system aids to measure the level of NfL and leads to determine the condition with PD.

Highly sensitive refractive index sensor for detection of Hg2+ based on Fano-like resonance in metal-dielectric-metal meta-structure

2021 ◽  
Author(s):  
Shuangxiu Yuan ◽  
Xuebo Sun ◽  
Jing Li ◽  
Yan Li ◽  
Fufang Su ◽  
...  
Keyword(s):  
Refractive Index ◽  
Limit Of Detection ◽  
Wavelength Shift ◽  
Refractive Index Sensor ◽  
Large Area ◽  
Amount Of Substance ◽  
Resonance Modes ◽  
Dipole Resonance ◽  
Highly Sensitive ◽  
Fabry Perot

Abstract We experimentally and theoretically investigate Fano-like resonance in large-area Au/SiO2/Au nano-patches meta-structure, which is originating from the coupling between Fabry Perot resonance and magnetic dipole resonance modes. A highly sensitive refractive index sensor based on the lineshape analysis is obtained. The extracted wavelength shift with the amount of substance of Hg2+ changing from 10-3 pmol to 1 nmol has a linear dependence, and the sensitivity can reach to ultra-low limit of detection (LOD) as 10-3 pmol. This study may provide an approach for the development and modification in sensing.

A Highly Sensitive and Label-Free Microbead-Based ‘Turn-On’ Colorimetric Sensor for the Detection of Mercury(II) in Urine Using a Peroxidase-Like Split G-Quadruplex–Hemin DNAzyme

2018 ◽  
Vol 71 (12) ◽  
pp. 945
Author(s):  
Xin Fu ◽  
He Zhang ◽  
Jie Zhang ◽  
Shi-Tong Wen ◽  
Xing-Cheng Deng
Keyword(s):  
Standard Deviation ◽  
Base Pair ◽  
Limit Of Detection ◽  
Label Free ◽  
Turn On ◽  
Highly Sensitive ◽  
Relative Standard ◽  
G Quadruplex ◽  
Catalytically Active ◽  
Partial Cdna

A highly sensitive and label-free microbead-based ‘turn-on’ assay was developed for the detection of Hg2+ in urine based on the Hg2+-mediated formation of intermolecular split G-quadruplex–hemin DNAzymes. In the presence of Hg2+, T–T mismatches between the two partial cDNA strands were stabilized by a T–Hg2+–T base pair, and can cause the G-rich sequences of the two oligonucleotides to associate to form a split G-quadruplex which is able to bind hemin to form the catalytically active G-quadruplex–hemin DNAzyme. This microbead-based ‘turn-on’ process allows the detection of Hg2+ in urine samples at concentrations as low as 0.5 pM. The relative standard deviation and recovery are 1.2–3.9 and 98.7–103.2%, respectively. The remarkable sensitivity for Hg2+ is mainly attributed to the enhanced mass transport ability that is inherent in homogeneous microbead-based assays. Compared with previous developments of intermolecular split G-quardruplex–hemin DNAzymes for the homogeneous detection of Hg2+ (the limit of detection was 19nM), a signal enhancement of ~1000 times is obtained when such an assay is performed on the surface of microbeads.

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