Abstract Novel electrochemical aptasensors based on glassy carbon electrodes modified with electropolymerized Neutral red and polycarboxylated macrocyclic ligands onto which the DNA aptamers were covalently attached have been developed for detection of Aflatoxin B1 (AFB1). The interaction an analyte resulted in decrease cathodic peak current probe measured by CV increase electron transfer resistance determined EIS. limit was found to be 0.1 nM 0.05 EIS methods, respectively. aptasensor makes...

Novel affinity biosensors for detecting cellular prions, PrPC, based on DNA aptamers and antibodies immobilized onto the carbon nanotubes have been designed compared in accordance with their binding ability analytical performance. The allowed us to detect PrPC limits of detection 20 50 pM. Keywords: Prion proteins, aptamers, antibodies, biosensor, multiwalled nanotubes, electrochemical quartz crystal microbalance

An impedimetric aptasensor for ochratoxin A (OTA) detection has been developed on the base of a gold electrode covered with new modifier consisting electropolymerized Neutral Red and mixture Au nanoparticles suspended in dendrimeric polymer Botlorn H30®. Thiolated aptamer specific to OTA was covalently attached via Au-S bonding. The interaction induced conformational switch from linear guanine quadruplex form followed by consolidation surface layer an increase charge transfer resistance....

Here we report the three-dimensional assembly of carbon nanotubes on polyelectrolyte-coated living Saccharomyces cerevisiae cells using polyelectrolyte-mediated layer-by-layer approach. Synthetic polyelectrolytes poly(allylamine hydrochloride) and poly(sodium 4-styrenesulfonate) were deposited surfaces yeast followed by deposition water-soluble oxidized multiwalled (MWNTs) an additional outermost polyelectrolyte bilayer. This resulted in fabrication polyelectrolyte/nanotubes composite...

Abstract An electrochemical aptasensor for ochratoxin A (OTA) detection has been developed on the base of a gold electrode covered with electropolymerized neutral red and silver nanoparticles obtained by chemical reduction macrocyclic ligands bearing catechol fragments. Thiolated aptamers against OTA were covalently attached to via AgS bonding. The interaction induced conformational switch aptamer, which caused increase charge transfer resistance measured EIS in presence ferricyanide ions....

Abstract Aptasensor for highly sensitive determination of aflatoxin M1 (AFM1) was developed on the base glassy carbon electrode (GCE) covered with polymeric Neutral red (NR) dye obtained by electropolymerization in presence polycarboxylated pillar[5]arene derivative. Aptamer against AFM1 and NR label were then covalently linked to carboxylic groups carrier carbodiimide binding. At cathodic peak current related conversion decreases. induced also an increase charge transfer resistance measured...

Carbon nanomaterials offer unique opportunities for the assembling of electrochemical aptasensors due to their high electroconductivity, redox activity, compatibility with biochemical receptors and broad possibilities functionalization combination other auxiliary reagents. In this review, progress in development based on carbon 2016–2020 is considered particular emphasis role materials aptamer immobilization signal generation. The synthesis properties nanotubes, graphene materials, nitride,...

Abstract A novel electrochemical DNA‐sensor based on glassy carbon electrode (GCE) modified with electropolymerized Neutral red (NR) and polycarboxylated thiacax[4]arene covalently attached mediator electrostatically adsorbed DNA was developed for sensitive detection of anthracycline preparations. Intercalation doxorubicin, daunorubicin idarubicin into increases the charge transfer resistance decreases electron exchange resulted in decay cathodic peak NR reduction. The makes it possible to...

Voltammetric DNA sensor has been proposed on the platform of glassy carbon electrode covered with black adsorbed pillar[5]arene molecules. Electropolymerization Neutral Red performed in presence native or oxidatively damaged resulted formation hybrid material which activity depended conditions. The assembling surface layer was confirmed by scanning electron microscopy and electrochemical impedance spectroscopy. influence redox polymeric dye investigated a significant increase peak currents...

Deep eutectic solvents have obtained growing interest in analytical chemistry due to opportunities related the green paradigm, i.e., substitution of organic solvents, application non-toxic ingredients and minimal quantities wastes formed their synthesis usage. In this work, advantages deep were shown development electrochemical sensor for epinephrine determination. Polythionine molecularly imprinted with (PTNMIP) was electrodeposited from natural solvent (NADES) consisted citric acid,...

A DNA sensor has been proposed on the platform of glassy carbon electrode modified with native implemented between two electropolymerized layers polyaniline. The surface layer was assembled by consecutive stages potentiodynamic electrolysis, drop casting, and second which required for capsulation molecules prevented their leaching into solution. Surface assembling controlled cyclic voltammetry, electrochemical impedance spectroscopy, atomic force, scanning electron microscopy. For...

A new voltammetric DNA sensor has been developed for doxorubicin determination on the platform of a glassy carbon electrode (GCE) covered with electropolymerized Azure B film and physically adsorbed native DNA. The redox properties polymeric were monitored at various pH scan rates. application decreased peak currents related to monomeric forms dye, whereas incubation in solution partially restored peaks accordance drug concentration. relative shift cathodic current caused by depended nominal...

A highly sensitive electrochemical DNA sensor for detection of the chemotherapeutic drug idarubicin mediated by Methylene blue (MB) has been developed. from fish sperm immobilized at electropolymerized layers Azure B. The incorporation MB into substantially increased sensitivity. concentration range determination cyclic voltammetry was 1 fM to 0.1 nM, with a limit (LOD) 0.3 fM. Electrochemical impedance spectroscopy (EIS) in presence redox probe ([Fe(CN)6]3−/4−) allowed widening linear 100...

Abstract Novel method of potentiometric detection DNA‐protein interactions has been proposed. For this purpose, polymeric phenothiazine dyes, methylene blue (MB) and green (MG), were electrochemically deposited onto the glassy carbon electrode covered with double stranded DNA (dsDNA) as a target for antibodies (DNA‐sensor) or aptamer specific to human α‐thrombin (aptasensor). The biosensors consecutively incubated at pH 7.5 3.0 difference in potentials, Δ E , was used measure protein...

Polyelectrolyte complexes based on electropolymerized phenothiazine dyes (Methylene Blue and Methylene Green), poly(allylamine hydrochloride), polystyrene sulfonate native DNA from salmon sperm have been for the first time obtained by self-assembling glassy carbon electrode using layer-by-layer assembly characterized direct current voltammetry electrochemical impedance spectroscopy. The changes in charge transfer resistance capacitance are attributed to separation regularity of layers...

Abstract Novel electrochemical DNA‐sensor based on glassy carbon electrode (GCE) modified with Ag nanoparticles, Neutral red covalently attached to its surface and native DNA adsorbed modifier coating was developed for the estimation of damage example model system Fenton reagent. As shown, oxidation process resulted in synchronous increase electron transfer resistance capacitance measured by impedance spectroscopy (EIS). The contribution each sensor component signal specified sensitivity...

Abstract The biosensors based on DNA aptamers immobilized by electrostatic adsorption onto electropolymerized Methylene Green (MG)) imprinted with have been developed and examined for thrombin detection in the range from 1 nM to μM using electrochemical impedance spectroscopy (EIS) potentiometry. participation of MG electropolymerization imprints formation was proved measurements EIS redox signals neutral charged indicators. Changes morphology layers were atomic force microscopy (AFM)....

We report on a new type of artificial receptor formed by hybridization two DNA aptamers for human thrombin (aptabody). This aptasensor based multiwalled carbon nanotubes allowed us to detect with detection limit 0.3 nM, which was 3 times better in comparison conventional aptamer. Keywords: aptamers, Hybridization, Human thrombin, Multiwalled nanotubes, Biosensor, Electrochemical quartz crystal microbalance