Rethinking the use of redox probes for the detection of electroactive proteins with electrochemical sensors modified with molecularly imprinted polymers.

This study aims to demonstrate that redox couples, regardless of their electrical charges, are unnecessary for detecting and quantifying electroactive proteins using an electrochemical sensor functionalized with a molecularly imprinted polymer. Our approach involved designing a polydopamine imprinted biosensor for detecting bovine serum albumin as the model protein. Electrochemical measurements were conducted in a phosphate-buffered solution (PBS) and solutions containing the negatively charged hexacyanoferrate, the neutral ferrocene, or the positively charged hexaammineruthenium (III) probes.

Predictive Factors for Bowel Resection in Childhood Intussusception.

Background: Intestinal intussusception is the most common cause of intestinal obstruction in infants and children under 3 years of age. Any delay in diagnosis or management can lead to intestinal ischaemia and perforation. The aim of this study is to determine the sociodemographic and clinical risk factors associated with bowel resection in infants and children with intussusception.

Designing a Simple Electrochemical Genosensor for the Detection of Urinary PCA3, a Prostate Cancer Biomarker.

This study investigates the feasibility of a simple electrochemical detection of Prostate Cancer Antigen 3 (PCA3) fragments extracted from patients' urine, using a thiolated single-strand DNA probe immobilized on a gold surface without using a redox probe. To enhance the PCA3 recognition process, we conducted a comparative analysis of the hybridization location using two thiolated DNA probes: Probe 1 targets the first 40 bases, while Probe 2 targets the fragment from bases 47 to 86. Hybridization with PCA3 followed, using square wave voltammetry.

Novel sensitive immunosensor for the selective detection of Engrailed 2 urinary prostate cancer biomarker.

Engrailed 2 (EN2) is a homeodomain-containing transcription factor expressed in prostate cancer (PCa) cell lines and is secreted into the urines. It is nowadays considered as a promising non-invasive biomarker for PCa early diagnosis. Herein, we report the design of an electrochemical immunosensor for EN2 detection.

Contribution to the Understanding of the Interaction between a Polydopamine Molecular Imprint and a Protein Model: Ionic Strength and pH Effect Investigation.

Several studies were devoted to the design of molecularly imprinted polymer (MIP)-based sensors for the detection of a given protein. Here, we bring elements that could contribute to the understanding of the interaction mechanism involved in the recognition of a protein by an imprint. For this purpose, a polydopamine (PDA)-MIP was designed for bovine serum albumin (BSA) recognition.

Legionella pneumophila sg1-sensing signal enhancement using a novel electrochemical immunosensor in dynamic detection mode.

This work presents a comparison between static and dynamic modes of biosensing using a novel microfluidic assay for continuous and quantitative detection of Legionella pneumophila sg1 in artificial water samples. A self-assembled monolayer of 16-amino-1-hexadecanethiol (16-AHT) was covalently linked to a gold substrate, and the resulting modified surface was used to immobilize an anti-Legionella pneumophila monoclonal antibody (mAb). The modified surfaces formed during the biosensor functionalization steps were characterized using electrochemical measurements and microscopic imaging techniques.

Computational approach and electrochemical measurements for protein detection with MIP-based sensor.

Rapid and accurate detection of proteins in biological fluids is increasingly required in the biomedical environment. Actually, it is performed with conventional techniques, which are generally run by robotized platforms at centralized laboratories. In this work, molecular dynamics calculations and an experimental procedure were conducted to set up electrochemical sensors based on polypyrrol (PPy) molecular imprinted polymers (MIP) for proteins detection.

Use of Tridacna maxima, a bivalve in the biomonitoring of the Saudi Arabian Red Sea coast.

The present study is an attempt to assess the effects of contamination of several sites in the Red Sea coasts of Saudi Arabia using bivalves as a biomonitoring tool. Oxidative stress biomarkers (including reduced glutathione level (GSH), glutathione-S-transferase activity (GST), Malondialdehyde level (MDA) and Catalase activity (CAT)), neurotoxicity acetylcholinesterase activity (ACHE), and genotoxicity micronucleus rate (MN) were measured in three distinct tissues - digestive glands, gills and mantle - of specimens of the giant clam Tridacna maxima, collected from five sites in Saudi Arabian Red Sea coast (Al-Khuraybah, Al-Wajh, Yanbu, Rabigh and Thuwal). Our results demonstrated that T.

Electrochemical and optical investigation of dental pulp stem cell adhesion on modified porous silicon scaffolds.

Extensive use of porous silicon (PSi) for tissue engineering is due to its convenient properties as it is both nontoxic and bioresorbable. Moreover, PSi surface modification is an important step to enhance cell adhesion and proliferation. In this work, a combination of optical and electrochemical studies is performed to elaborate a suitable PSi multilayer substrate for cell culture.

Detection of plasma MMP-9 within minutes. Unveiling some of the clues to develop fast and simple electrochemical magneto-immunosensors.

Magnetic beads (MB) have been extensively used to produce sensitive and efficient electrochemical magneto-immunosensors. However, MB effective handling requires training, and MB washing after each incubation step is time consuming and contributes to raise result variability. Consequently, most of the electrochemical magneto-immunosensors reported to date, which entailed relatively long and complex multi-step procedures, would be difficult to carry out at point-of-care (POC) settings or by laypersons.

Using magnetic beads and signal amplifiers to produce short and simple immunoassays: Application to MMP-9 detection in plasma samples.

Magnetic beads (MB) and signal amplifiers, such as horseradish peroxidase polymers (poly-HRP), have been used before for the production of highly sensitive immunoassays. However, most of the examples reported previously entailed long and tedious multi-step procedures, which were not necessarily shorter or simpler than classical paths such as Enzyme-Linked Immunosorbent Assay (ELISA). Here, instead of exploiting the combination of MB and poly-HRP to ameliorate sensitivity, we show that they conform a powerful tool that can be used to shorten the incubation times, which allows optimizing extremely simple, fast and efficient immunoassays with minimal technical requirements.

Impact of chlorhexidine digluconate and temperature on curli production in -consequence on its adhesion ability.

Chlorhexidine-Digluconate (CHX-Dg) is a biocide widely used as disinfectant or antiseptic in clinical and domestic fields. It is often found in the formulation of solutions to treat superficial wounds. Nevertheless, few studies have focused on its effects on while this bacterium is commonly involved in mixed infections.

Highly Selective Polypyrrole MIP-Based Gravimetric and Electrochemical Sensors for Picomolar Detection of Glyphosate.

There is a global debate and concern about the use of glyphosate (Gly) as an herbicide. New toxicological studies will determine its use in the future under new strict conditions or its replacement by alternative synthetic or natural herbicides. In this context, we designed biomimetic polymer sensing layers for the selective molecular recognition of Gly.

Ultrasensitive Electrochemical Sensors for PSA Detection: Related Surface Functionalization Strategies.

Prostate cancer is the most common male cancer in the world. The diagnosis, staging, prognosis and monitoring are usually done with Prostate Specific Antigen (PSA). Biosensors are emerging as a novel analytical technology for PSA detection.

Application of APTES-Anti-E-cadherin film for early cancer monitoring.

Cancer staging is a way to classify cancer according to the extent of the disease in the body. The stage is usually determined by several factors such as the location of the primary tumor, the tumor size, the degree of spread in the surrounding tissues, etc. The study of E-cadherin (EC) expression on cancerous cells of patients has revealed variations in the molecular expression patterns of primary tumors and metastatic tumors.

AFM, CLSM and EIS characterization of the immobilization of antibodies on indium-tin oxide electrode and their capture of Legionella pneumophila.

The microscopic surface molecular structures and properties of monoclonal anti-Legionella pneumophila antibodies on an indium-tin oxide (ITO) electrode surface were studied to elaborate an electrochemical immunosensor for Legionella pneumophila detection. A monoclonal anti-Legionella pneumophila antibody (MAb) has been immobilized onto an ITO electrode via covalent chemical bonds between antibodies amino-group and the ring of (3-Glycidoxypropyl) trimethoxysilane (GPTMS). The functionalization of the immunosensor was characterized by atomic force microscopy (AFM), water contact angle measurement, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in the presence of [Fe(CN)₆](3-/4-) as a redox probe.

Discriminating DNA mismatches by electrochemical and gravimetric techniques.

A silicon nitride functionalized electrode and a 104 MHz lithium tantalate (LiTaO₃) surface acoustic wave (SAW) sensor have been used to investigate target-probe recognition processes. Electrochemical and gravimetric measurements have been considered to monitor hybridization of single base mismatch (SBM) in synthetic oligonucleotides and single-nucleotide polymorphisms ApoE in real clinical genotypes. Obvious discrimination of SBM in nucleotides has been shown by both gravimetric and electrochemical techniques, without labeling nor amplification.

Electrochemical impedance spectroscopy as a highly sensitive tool for a dynamic interaction study between heparin and antithrombin: a novel antithrombin sensor.

Specific recognition between two biological partners is widely exploited in biosensors nowadays. To explore this avenue, a novel biosensor for antithrombin (AT) detection was constructed. Heparin was used as the affinity ligand.

Highly hydrophilic surfaces from polyglycidol grafts with dual antifouling and specific protein recognition properties.

Homopolymer grafts from α-tert-butoxy-ω-vinylbenzyl-polyglycidol (PGL) were prepared on gold and stainless steel (SS) substrates modified by 4-benzoyl-phenyl (BP) moieties derived from the electroreduction of the parent salt 4-benzoyl benzene diazonium tetrafluoroborate. The grafted BP aryl groups efficiently served to surface-initiate photopolymerization (SIPP) of PGL. In similar conditions, SIPP of hydroxyethyl methacrylate (HEMA) permitted the production of PHEMA grafts as model surfaces.

Electrochemical monitoring of chlorhexidine digluconate effect on polyelectrolyte immobilized bacteria and kinetic cell adhesion.

The electrochemical impedance spectroscopy (EIS) technique has been used as a sensitive method to explore the effect of antibacterial molecules on immobilized bacteria and biofilm formation. In this work, we describe the electrochemical spectroscopy as a powerful method to monitor the effect of chlorhexidine digluconate (CHX-Dg) on polyelectrolyte immobilized Escherichia coli K12 MG1655 and the kinetics of cell adhesion on gold electrodes. The experimental impedance data were modeled with a Zview program to find the best equivalent electrical circuit and analyse its parameter's properties.

Love-wave bacteria-based sensor for the detection of heavy metal toxicity in liquid medium.

The present work deals with the development of a Love-wave bacteria-based sensor platform for the detection of heavy metals in liquid medium. The acoustic delay-line is inserted in an oscillation loop in order to record the resonance frequency in real-time. A Polydimethylsiloxane (PDMS) chip with a liquid chamber is maintained by pressure above the acoustic wave propagation path.

Assessing bacterial adhesion using DLVO and XDLVO theories and the jet impingement technique.

In this study, the adhesion of two bacterial strains (Pseudomonas stutzeri PS, and Staphylococcus epidermidis, SE) to the glass and the indium tin oxide (ITO)-coated glass surfaces was examined qualitatively and quantitatively using the theoretical approaches and the jet impingement technique. A comparison between the DLVO and the extended DLVO (XDLVO) theories showed that the XDLVO predictions of bacterial adhesion and its reversibility are more accurate than DLVO predictions. The adhesion tests revealed that PS bacteria has much better adhesion rate than SE bacteria to both material surfaces, as predicted by XDLVO approach.

Surface assembly on biofunctional magnetic nanobeads for the study of protein-ligand interactions.

One of the major challenges of proteomics today is to increase the power potential for the identification of as many proteins as possible and to characterize their interactions with specific free ligands (interactomics) or present on cell walls (cell marker), in order to obtain a global, integrated view of disease processes, cellular processes and networks at the protein level. The work presented here proposes the development of biofunctionalized magnetic nanobeads that might be used for interactomic investigations. The strategy consisted in immobilizing proteins via a non covalent technique that provides greater possibilities for the advent of faster, cheaper and highly miniaturizable protein analysis systems, in particular in situations where the amount of isolated protein is scarce (trace proteins).

Evaluation of endothelial cell adhesion onto different protein/gold electrodes by EIS.

To study cell attachment to biomaterials, several proteins such as fibronectin, collagen IV, heparin, immunoglobulin G, and albumin have been deposited onto polystyrene adsorbed on a self-assembled monolayer (silane or thiol) on glass or gold, respectively. The different steps of this multilayer assembly have been characterized by electrochemical impedance spectroscopy (EIS). These data are compared to those of adhesion rate, viability percentage, and cytoskeleton labeling for a better understanding of the cell adhesion process to each protein.

Immobilization of E. coli bacteria in three-dimensional matrices for ISFET biosensor design.

In recent years, cell-based biosensors (CBBs) have been very useful in biomedicine, food industry, environmental monitoring and pharmaceutical screening. They constitute an economical substitute for enzymatic biosensors, but cell immobilization remains a limitation in this technology. To investigate into the potential applications of cell-based biosensors, we describe an electrochemical system based on a microbial biosensor using an Escherichia coli K-12 derivative as a primary transducer to detect biologically active agents.