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We propose a salivary Interleukin‐10 detection strategy as part of an easily integrable Lab‐on‐Chip and Point‐of‐Care IMFET for multi‐detection Heart Failure (HF) biomarkers. Our developed IMFET showed good linearity between increasing IL‐10 concentration and the charge transfer resistance in both standard solutions and real saliva samples with a LOD of 0.02 pg mL−1. Moreover, the cross‐selectivity study showed that the developed IMFET was highly selective towards IL‐10 against other HF biomarkers. The precision of our IMFET was also evaluated, and the difference between the determined IL‐10 concentration using the standard addition method and its expected one is<20 %. [ABSTRACT FROM AUTHOR]

The review presents advances and main challenges of the affinity sensors based on field‐ effect transistors published during the last five years. The different nanomaterial‐based field‐effect transistors are classified according to the nature of the nanomaterials, beginning by silicon, the "gold‐standard" semiconductor, the gallium nitride semiconductor, the organic semiconductors, the silicon nanowires, the inorganic nanomaterials, the carbon nanotubes and the graphene. Due to its exceptional electrical properties, the main works are devoted to graphene. The obtained analytical performances for the detection of biomarkers, of DNA sequences and of miRNA are listed. The relation between the operational conditions ‐ nature of the nanomaterials, procedure of preparation, choice of the receptor molecule, method of immobilization – and the analytical performance are discussed. The perspective of industrialization of these affinity sensors based on field‐effect transistors is discussed. [ABSTRACT FROM AUTHOR]

Instant determination of glucose levels is necessary to monitor the treatment of diabetes. The next generation of electrochemical sensors aims to eliminate the use of enzymes because of their lack of stability and the complex procedure to immobilize them on the electrode. In this paper Pr1.92Ba0.08Ni0.95Zn0.05O4+δ perovskite, a A2BO4+δ type, was tested, for the first time for non enzymatic detection of glucose. It was synthesized by a sol‐gel method. The obtained crystallized powder was structurally characterized by XRD, morphologically characterized by SEM and EDX and electrochemically characterized. A monoclinic crystallographic system was formed. The presence of Pr2O3 during synthesis and calcination is in agreement with the formation of defects in the crystalline network and the disproportionation of NiIII sites into NiII and NiIV, due to the substitution of Pr by Ba. The oxido‐reduction of NiII sites is observed by cyclic voltammetry. The electrocatalytic oxidation of glucose through the electrooxidized NiII site was observed on a gold electrode, at 481 mV. The analytical performance of this glucose sensor is good in comparison to previously published ABO3 perovskite modified electrodes, in terms of dynamic range (1.5 μM–7000 μM) and detection limit (0.5 μM). Its application to human serum shows that there is no interference for glucose detection. [ABSTRACT FROM AUTHOR]

A K+-sensitive capacitive electrolyte-membrane-insulator-semiconductor (EMIS) based on a novel dibromoaza[7]helicene ionophore has been developed. An ion-sensitive membrane based on polyvinylchloride (PVC) doped with the ionophore was deposited on the Si3N4/SiO2/Si-p/Cu-Al transducer. The properties of the K+-EMIS chemical sensor were investigated by electrochemical impedance spectroscopy (EIS). All the developed devices upon being tested have shown good sensitivity and linearity responses within the range 10-6 M to 10-1 M of potassium activity, with good selectivity over a wide variety of other cations (Na+, Li+, Cu2+, Ca2+, and Mg2+). To our knowledge, this is the first time that a capacitive field-effect sensor has been fabricated using helicene as a carrier for K+-detection, combined with the structure: Si3N4/SiO2/Si-p/Cu-Al as a transducer. [ABSTRACT FROM AUTHOR]

Interleukin-8 (IL-8), a dimeric protein composed of two identical subunits, is overexpressed in different human cancers, among them pancreatic cancers and head and neck cancers. There is a strong demand for monitoring of this biomarker protein for early cancer detection. A new concept of label-free impedimetric immunosensors for IL-8 detection is described in this work. A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core is synthesized using cysteamine as linker, and characterized using TEM and UV-Vis spectrometry. After immobilization of these Fe3O4@Au magnetic nanocomposites on a boron doped diamond (BDD) electrode using a simple magnet, anti-human IL-8 monoclonal antibody is linked to the AuNPs, previously functionalized with thioctic acid. The functionalization of the immunosensor was characterized using two electrochemical techniques: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), performed in phosphate buffer with ferro/ferricyanide as the redox probe. The EIS technique was used for affinity assays: antibody-Antigen binding. A linear relationship between the increment in the electron transfer resistance (RCT) and the logarithmic value of IL-8 concentration was observed between 0.1 pg/mL and 1000 pg/mL. The limit of detection (LOD) was estimated at 0.03 pg/mL. [ABSTRACT FROM AUTHOR]