scholarly journals Impedimetric Immunosensor Utilizing Polyaniline/Gold Nanocomposite-Modified Screen-Printed Electrodes for Early Detection of Chronic Kidney Disease

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3990 ◽  
Author(s):  
Muhammad Omar Shaikh ◽  
Boyanagunta Srikanth ◽  
Pei-Yu Zhu ◽  
Cheng-Hsin Chuang
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Early Detection ◽  
Electrochemical Impedance ◽  
High Specificity ◽  
Homogeneous Distribution ◽  
Label Free ◽  
Gold Nanocrystals ◽  
Working Electrode ◽  
Label Free Detection

The presence of small amounts of human serum albumin (HSA) in urine or microalbuminuria (30–300 µg/mL) is a valuable clinical biomarker for the early detection of chronic kidney disease (CKD). Herein, we report on the development of an inexpensive and disposable immunosensor for the sensitive, specific, and label-free detection of HSA using electrochemical impedance spectroscopy (EIS). We have utilized a simple one-step screen-printing protocol to fabricate the carbon-based three-electrode system on flexible plastic substrates. To enable efficient antibody immobilization and improved sensitivity, the carbon working electrode was sequentially modified with electropolymerized polyaniline (PANI) and electrodeposited gold nanocrystals (AuNCs). The PANI matrix serves as an interconnected nanostructured scaffold for homogeneous distribution of AuNCs and the resulting PANI/AuNCs nanocomposite synergically improved the immunosensor response. The PANI/AuNCs-modified working electrode surface was characterized using scanning electron microscopy (SEM) and the electrochemical response at each step was analyzed using EIS in a ferri/ferrocyanide redox probe solution. The normalized impedance variation during immunosensing increased linearly with HSA concentration in the range of 3–300 µg/mL and a highly repeatable response was observed for each concentration. Furthermore, the immunosensor displayed high specificity when tested using spiked sample solutions containing different concentrations of actin protein and J82 cell lysate (a complex fluid containing a multitude of interfering proteins). Consequently, these experimental results confirm the feasibility of the proposed immunosensor for early diagnosis and prognosis of CKD at the point of care.

scholarly journals Label-free Electrochemical Impedance Spectroscopy Aptasensor for Ultrasensitive Detection of Lung Cancer Biomarker Carcinoembryonic Antigen

2021 ◽  
Vol 9 ◽  
Author(s):  
Yawei Wang ◽  
Lei Chen ◽  
Tiantian Xuan ◽  
Jian Wang ◽  
Xiuwen Wang
Keyword(s):  
Carcinoembryonic Antigen ◽  
Self Assembly ◽  
Electrochemical Impedance ◽  
Reference Electrode ◽  
Electrode System ◽  
Impedance Change ◽  
Label Free ◽  
Working Electrode ◽  
Label Free Detection ◽  
Assembly Technique

In this work, an integrated electrode system consisting of a graphene working electrode, a carbon counter electrode and an Ag/AgCl reference electrode was fabricated on an FR-4 glass fiber plate by a polyethylene self-adhesive mask stencil method combined with a manual screen printing technique. The integrated graphene electrode was used as the base electrode, and AuNPs were deposited on the working electrode surface by cyclic voltammetry. Then, the carcinoembryonic antigen aptamer was immobilized using the sulfhydryl self-assembly technique. The sensor uses [Fe(CN)6]3−/4− as a redox probe for label free detection of carcinoembryonic antigen based on the impedance change caused by the difference in electron transfer rate before and after the binding of carcinoembryonic antigen aptamer and the target carcinoembryonic antigen. The results showed a good linear relationship when the CEA concentration is in the range of 0.2–15.0 ng/ml. The detection limit was calculated to be 0.085 ng/ml (S/N = 3).

Electrokinetics-Based Microfluidic Technology for the Rapid Separation and Concentration of Bacteria/Cells/Biomolecules

2014 ◽  
Vol 911 ◽  
pp. 347-351 ◽  
Author(s):  
I Fang Cheng ◽  
Tzu Ying Chen ◽  
Hsien Chang Chang
Keyword(s):  
Cancer Cell ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
High Specificity ◽  
Cell Detection ◽  
Label Free ◽  
Rapid Separation ◽  
Whole Cells ◽  
Highly Sensitive ◽  
Label Free Detection

Conventional techniques for detection of bacteria/cell and assessment of cancer cell typically use DNA techniques, Western blot and ELISA kits that are high cost, complicated processes and long time consuming. Our researches focus on rapid, portable, simple and highly sensitive separation and detection of cells/bacteria/biomolecules for field-use diagnosis. An ideal portable biosensor (molecular or whole cells detections) unit must have several important features: rapid detection time (<10 minutes), high sensitivity (pM level for molecular detection, 103 cells/ml for whole cell detection), high specificity, small and inexpensive instrumentation configuration. Electrochemical impedance/conductance sensing is preferred over optical detection because of cost and portability concerns. Cancer cell detection using heterogeneous medical samples require continuous isolation, sorting, and trapping of the target bioparticles and immunocolloids within a diagnostic chip. We have developed several electrokinetic strategies to rapid separation, concentration and detection of cells/bacteria/biomolecules in a microfluidic chip using such as dielectrophoresis (DEP), traveling-wave dielectrophoresis (twDEP) and electrohydrodynamics (EHD). Several key techniques we done, which on a rapid/simple/label-free detection platform for the highly sensitive on-chip separation/identification/quantification will be introduced in this paper.

scholarly journals Label-Free Electrochemical Sensor for Rapid Bacterial Pathogen Detection Using Vancomycin-Modified Highly Branched Polymers

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1872
Author(s):  
Holger Schulze ◽  
Harry Wilson ◽  
Ines Cara ◽  
Steven Carter ◽  
Edward N. Dyson ◽  
...  
Keyword(s):  
Pathogen Detection ◽  
Electrochemical Impedance ◽  
Point Of Care ◽  
Branched Polymers ◽  
Label Free ◽  
Conformation Change ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Staphylococcus Carnosus ◽  
Label Free Detection

Rapid point of care tests for bacterial infection diagnosis are of great importance to reduce the misuse of antibiotics and burden of antimicrobial resistance. Here, we have successfully combined a new class of non-biological binder molecules with electrochemical impedance spectroscopy (EIS)-based sensor detection for direct, label-free detection of Gram-positive bacteria making use of the specific coil-to-globule conformation change of the vancomycin-modified highly branched polymers immobilized on the surface of gold screen-printed electrodes upon binding to Gram-positive bacteria. Staphylococcus carnosus was detected after just 20 min incubation of the sample solution with the polymer-functionalized electrodes. The polymer conformation change was quantified with two simple 1 min EIS tests before and after incubation with the sample. Tests revealed a concentration dependent signal change within an OD600 range of Staphylococcus carnosus from 0.002 to 0.1 and a clear discrimination between Gram-positive Staphylococcus carnosus and Gram-negative Escherichia coli bacteria. This exhibits a clear advancement in terms of simplified test complexity compared to existing bacteria detection tests. In addition, the polymer-functionalized electrodes showed good storage and operational stability.

scholarly journals Microfluidic Impedance Biosensor Chips Using Sensing Layers Based on DNA-Based Self-Assembled Monolayers for Label-Free Detection of Proteins

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 80
Author(s):  
Khaled Alsabbagh ◽  
Tim Hornung ◽  
Achim Voigt ◽  
Sahba Sadir ◽  
Taleieh Rajabi ◽  
...  
Keyword(s):  
Troponin I ◽  
Electrochemical Impedance ◽  
Specific Binding ◽  
Self Assembled Monolayers ◽  
Significant Shift ◽  
Label Free ◽  
Label Free Detection ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Biosensor Chip

A microfluidic chip for electrochemical impedance spectroscopy (EIS) is presented as bio-sensor for label-free detection of proteins by using the example of cardiac troponin I. Troponin I is one of the most specific diagnostic serum biomarkers for myocardial infarction. The microfluidic impedance biosensor chip presented here consists of a microscope glass slide serving as base plate, sputtered electrodes, and a polydimethylsiloxane (PDMS) microchannel. Electrode functionalization protocols were developed considering a possible charge transfer through the sensing layer, in addition to analyte-specific binding by corresponding antibodies and reduction of nonspecific protein adsorption to prevent false-positive signals. Reagents tested for self-assembled monolayers (SAMs) on gold electrodes included thiolated hydrocarbons and thiolated oligonucleotides, where SAMs based on the latter showed a better performance. The corresponding antibody was covalently coupled on the SAM using carbodiimide chemistry. Sampling and measurement took only a few minutes. Application of a human serum albumin (HSA) sample, 1000 ng/mL, led to negligible impedance changes, while application of a troponin I sample, 1 ng/mL, led to a significant shift in the Nyquist plot. The results are promising regarding specific detection of clinically relevant concentrations of biomarkers, such as cardiac markers, with the newly developed microfluidic impedance biosensor chip.

Diagnostic accuracy of different methods of early detection of chronic kidney disease

2017 ◽  
Vol 25 (4) ◽  
pp. 401-407
Author(s):  
Luciana Saraiva da Silva ◽  
Rosângela Minardi Mitre Cotta ◽  
Tiago Ricardo Moreira ◽  
Rodrigo Gomes da Silva
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Early Detection ◽  
Diagnostic Accuracy

Proteinuria

2020 ◽  
Vol 13 (3) ◽  
pp. 152-158
Author(s):  
Lauren Copeland ◽  
Keith Gillis
Keyword(s):  
Primary Care ◽  
Chronic Kidney Disease ◽  
Risk Factor ◽  
Kidney Disease ◽  
Early Detection ◽  
Renal Disease ◽  
Independent Risk Factor ◽  
Prognostic Significance ◽  
Urinary Protein ◽  
Progression Of Renal Disease

Measurement of urinary protein is an essential part of the evaluation of chronic kidney disease; it has both diagnostic and prognostic significance. Proteinuria is an independent risk factor for progression of renal disease, but is also independently associated with increased cardiovascular mortality. Despite its far-reaching implications, the definition, diagnosis and treatment of proteinuria can cause confusion in primary care. Early detection of proteinuria in the context of diabetes or otherwise is vital given the potential for intervention to reduce urinary protein losses and improve renal and cardiovascular outcomes. This article will focus on the definition, potential causes and management of proteinuria, including which individuals should be referred to secondary care.

Early detection and diagnosis of vascular calcification in patients with chronic kidney disease

2014 ◽  
Vol 25 (6) ◽  
pp. e79
Author(s):  
Violeta Knežević ◽  
Aleksandar Knežević ◽  
Tatjana Mirković ◽  
Gorica Mališanović ◽  
Ljiljana Gvozdenović
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Early Detection ◽  
Vascular Calcification ◽  
Detection And Diagnosis ◽  
Early Detection And Diagnosis

scholarly journals Proteomic Characterization of High-Density Lipoprotein Particles from Non-Diabetic Hemodialysis Patients

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 671 ◽  
Author(s):  
Florens ◽  
Calzada ◽  
Delolme ◽  
Page ◽  
Guebre Egziabher ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Cardiovascular Risk ◽  
Kidney Disease ◽  
Hypothesis Test ◽  
Density Lipoprotein ◽  
Biological Properties ◽  
Hemodialysis Patients ◽  
High Density ◽  
High Density Lipoproteins ◽  
Label Free

Chronic kidney disease is associated with an increased cardiovascular risk, and altered biological properties of high-density lipoproteins (HDL) may play a role in these events. This study aimed to describe the HDL proteome from non-diabetic hemodialysis patients and identify potential pathways affected by the dysregulated expression of HDL proteins. HDL were sampled from nine non-diabetic hemodialysis (HD) and eight control patients. Samples were analyzed using a nano-RSLC coupled with a Q-Orbitrap. Data were processed by database searching using SequestHT against a human Swissprot database and quantified with a label-free quantification approach. Proteins that were in at least five of the eight control and six of the nine HD patients were analyzed. Analysis was based on pairwise ratios and the ANOVA hypothesis test. Among 522 potential proteins, 326 proteins were identified to be in the HDL proteome from HD and control patients, among which 10 were significantly upregulated and nine downregulated in HD patients compared to the control patients (p < 0.05). Up and downregulated proteins were involved in lipid metabolism, hemostasis, wound healing, oxidative stress, and apoptosis pathways. This difference in composition could partly explain HDL dysfunction in the chronic kidney disease (CKD) population and participate in the higher cardiovascular risk observed in this population.

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