Abstract Enzyme‐based biofuel cells provide versatile means to generate electrical power from biomass or substrates, and use biological fluids as fuel‐sources for the activation of implantable electronic medical devices, prosthetic aids. This review addresses recent advances assembling based on integrated, electrically contacted thin film‐modified enzyme electrodes. Different methods communicate enzymes associated with anodes/cathodes cell elements are presented. These include: (i) The...

Electrochemical sensors for the analysis of TNT with enhanced sensitivities are described. The achieved by tailoring π-donor−acceptor interactions between and π-donor-modified electrodes or π-donor-cross-linked Au nanoparticles linked to electrode. In one configuration a p-aminothiophenolate monolayer-modified electrode leads sensitivity corresponding 17 ppb (74 nM). second configuration, cross-linking NPs oligothioaniline bridges yields functionalized that detects corresponds 460 ppt (2...

A bis-aniline-cross-linked Au nanoparticles (NPs) composite is electropolymerized on surfaces. The association of trinitrotoluene, TNT, to the bis-aniline bridging units via pi-donor-acceptor interactions allows amplified detection TNT by following surface plasmon resonance (SPR) reflectance changes as a result coupling between localized AuNPs and wave associated with gold surface. limit for analyzing this method approximately 10 pM. electropolymerization in presence picric acid results...

The hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme is assembled on Au electrodes. It reveals bioelectrocatalytic properties and electrocatalyzes the reduction of H2O2. functions are used to develop electrochemical sensors that follow activity glucose oxidase biosensors for detection DNA or low-molecular-weight substrates (adenosine monophosphate, AMP). Hairpin nucleic structures include G-quadruplex sequence in a caged configuration acid complementary analyte DNA, aptamer AMP,...

A three-dimensional composite consisting of the oxygen-insensitive flavin-dependent glucose dehydrogenase, GDH, and Au nanoparticles (NPs) is assembled on a surface using an electropolymerization process. The bis-aniline-cross-linked GDH/Au NPs reveals effective electrical contact with electrode (ket = 1100 s−1), bioelectrocatalyzed oxidation driven by enzyme/NPs matrix. NPs-functionalized implemented as amperometric sensor, it superior functions when compared to analogous oxidase/Au system....

The hemin/G-quadruplex nanostructure and the Pb(2+)-dependent DNAzyme are implemented to develop sensitive surface plasmon resonance (SPR) electrochemical sensing platforms for Pb(2+) ions. A complex consisting of sequence a ribonuclease-containing nucleic acid (corresponding substrate DNAzyme) linked G-rich domain, which is "caged" in structure, assembled on Au-coated glass surfaces or Au electrodes. In presence ions, cleaves substrate, leading separation self-assembly support. one...

Au nanoparticles (NPs) are functionalized with thioaniline electropolymerizable groups and (mercaptophenyl)boronic acid. The antibiotic substrates neomycin (NE), kanamycin (KA), streptomycin (ST) include vicinal diol functionalities and, thus, bind to the boronic acid ligands. electropolymerization of NPs in presence NE, KA, or ST onto surfaces yields bisaniline-cross-linked NP composites that, after removal ligated antibiotics, provide molecularly imprinted matrixes which reveal high...

An ultrasensitive SPR-detection of the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is achieved by composites Kemp's acid molecularly imprinted Au nanoparticles crosslinked bisaniline units on a surface (see figure).

A DNA construct consisting of a nucleic acid template, (1), on which acid-modified glucose oxidase (GOx), (3), was hybridized by cooperative bridging the T−Hg2+−T units, and acid-functionalized ferrocene, (5), directly Au electrode. The resulting nanostructure revealed bioelectrocatalytic activities, where ferrocene units mediated electron transfer between redox center enzyme functions system are regulated concentration Hg2+ ions, controls content associated with template means units. This...

The porous high surface area and conducting properties of mesoporous carbon nanoparticles, CNPs (<500 nm diameter NPs, pore dimensions ∼6.3 nm), are implemented to design electrically contacted enzyme electrodes for biosensing biofuel cell applications. relay units ferrocene methanol, Fc-MeOH, methylene blue, MB(+), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS(2-), loaded in the pores CNPs, capped with glucose oxidase, GOx, horseradish peroxidase, HRP, or bilirubin BOD,...

Abstract Layered assemblies of photosystem I, PSI, and/or II, PSII, on ITO electrodes are constructed using a layer‐by‐layer deposition process, where poly N,N ′‐dibenzyl‐4,4′‐bipyridinium (poly‐benzyl viologen, PBV 2+ ) is used as an inter‐protein “glue”. While the layered assembly PSI generates anodic photocurrent only in presence sacrificial electron donor system, such dichlorophenol indophenol (DCPIP)/ascorbate, PSII‐modified electrode leads, upon irradiation, to formation (while...

The self-assembly of labeled aptamer sub-units in the presence their substrates provides a method for optical (fluorescence) or electrochemical detection substrate. One is linked to CdSe/ZnS quantum dots (QDs), and dye-functionalized second sub-unit with modified QDs, cocaine, stimulates fluorescence resonance energy transfer (FRET). This enables cocaine limit corresponding 1 x 10(-6) M. Alternatively, fragments are pyrene units. formation supramolecular aptamer-substrate complex...

The anti-cocaine aptamer was fragmented into two nucleic acids, (1) and (2). acid tethered at its 5′-end to aminoethyl nicotinamide adenine dinucleotide, amino-NAD+, or horseradish peroxidase, HRP. (2) functionalized 3′-end with alcohol dehydrogenase, AlcDH, glucose oxidase, GOx. In the presence of cocaine, supramolecular NAD+/AlcDH/cocaine−aptamer complex is formed, biocatalytic oxidation ethanol activated. Similarly, in GOx/HRP/cocaine−aptamer this activates cascade where oxidized by GOx...

Molecularly imprinted Au nanoparticles (NPs) composites are generated on Au-coated glass surfaces. The imprinting process involves the electropolymerization of thioaniline-functionalized NPs (3.5 nm) a thioaniline monolayer-modified surface in presence carboxylic acid, acting as template analogue for respective explosive. exclusion from matrix yields composites. binding analyte explosives to matrixes is probed by plasmon resonance spectroscopy, SPR, where electronic coupling between...

Abstract Thiolated nucleic acid hairpin nanostructures that include in their stem region a “caged” G‐quadruplex sequence, and single‐stranded loop oligonucleotide recognition sequences for DNA, adenosine monophosphate (AMP), or Hg 2+ ions were linked to bare Au surfaces nanoparticles (NPs) surfaces. The opening of the associated with surface by complementary target AMP substrate, ions, presence hemin, led self‐assembly hemin/G‐quadruplexes on surface. resulting dielectric changes exhibited...

Photo-bioelectrochemical cells are devices that use biomolecule-modified electrodes for the conversion of solar light to electrical power. We present construction a layered assembly native photosynthetic reaction centers photosystem I (PSI) and II (PSII), crosslinked by polyvinyl pyridine/methyl pyridinium cytochrome c (Cyt. c) act as an electron transfer mediating layer. Electrostatic interactions glutaric dialdehyde crosslinking protein layers stabilize biomolecules on electrodes. The...

Pt nanocrystals are implanted into photosystem I (PSI) by a photochemical reaction. The PSI with the associated nanoclusters was modified thioaniline and electropolymerized thioaniline-functionalized nanoparticles (NPs) to yield bis-aniline-cross-linked PSI/Pt NPs composite. alignment of respect leads effective charge separation generation photocurrent, ϕ (λ = 420 nm) 2.6%, IPCE ∼ 0.35%. bis-aniline units cross-linking composite exhibit quasireversible redox features (E0′ 0.05 V vs Ag/AgCl,...

Au nanoparticles (NPs) functionalized with thioaniline and cysteine are used to assemble bis-aniline-bridged Au-NP composites on surfaces using an electropolymerization process. During the polymerization of NPs in presence different amino acids, for example, L-glutamic acid, L-aspartic L-histidine, L-phenylalanine, zwitterionic interactions between acids units linked particles lead formation molecularly imprinted sites electropolymerized composites. Following elimination template acid...

Abstract The native photosynthetic reaction centers photosystem I (PSI) and II (PSII) act as functional nanostructures for the assembly of photo‐biofuel cells. By electrical wiring PSI and/or PSII with electrodes, conversion light energy into power has been demonstrated. Different methodologies to electrically contact photosystems electrodes have developed, including reconstitution on relay units, application redox‐active polymers charge‐transport matrices, use metallic nanoparticles or...

An integrated platinum nanoparticles (NPs)/glucose oxidase (GOx) composite film associated with a Au electrode is used to follow the biocatalytic activities of enzyme. The assembled on by electropolymerization thioaniline-functionalized Pt NPs and thioaniline-modified GOx. resulting enzyme/Pt NPs-functionalized stimulates O 2 oxidation glucose gluconic acid H 2O 2. modified then implemented activity enzyme electrochemical monitoring generated effect composition NPs/GOx cross-linked...

Glucose oxidase, GOx, functionalized with Au nanoparticles is linked to a electrode. The biocatalytic enlargement of the yields matrix for immobilization electroactive ferrocene units and improved charge transport through assembly enhances ferrocene-mediated bioelectrocatalytic activation enzyme.

Abstract Imprinted polymer films for the selective analysis of D‐glucose and D‐mannose are prepared by co‐electropolymerization phenol with a 3‐hydroxyphenyl boronic acid‐monosaccharide complex containing or on Au support. The monosaccharides is based competitive electrochemical assay that employs ferrocene‐modified‐monosaccharides as redox labels. Similarly, enantioselectivity demonstrated imprint recognition sites in application redox‐active indicator.

Sweet sensor: A bis-aniline-cross-linked Au nanoparticles (NPs)/glucose oxidase composite has been electropolymerized on a electrode (see picture). The integrated NPs/enzyme provides an effective matrix for making electrical contact with the enzyme, and this yields specific amperometric glucose biosensor.Electropolymerizable (GOx) was synthesized by tethering of thioaniline units to protein. electropolymerization thioaniline-modified GOx in presence thioaniline-functionalized (NPs) yielded...