Publications by authors named "Dimitra G Georganopoulou"

The limb-girdle muscular dystrophies (LGMD) are a collection of genetic diseases united in their phenotypical expression of pelvic and shoulder area weakness and wasting. More than 30 subtypes have been identified, five dominant and 26 recessive. The increase in the characterization of new genotypes in the family of LGMDs further adds to the heterogeneity of the disease.

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Herein we report the development of a simple, rapid, homogeneous, and sensitive detection system for DNA based on the scattering properties of silver-amplified gold nanoparticle probes. The assay uses DNA-functionalized magnetic particle probes that act as scavengers for target DNA, which can be collected via a magnetic field. Once the DNA targets are isolated from the initial sample, they are sandwiched via hybridization by a second set of probes.

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Functionalized nanoparticles hold great promise in realizing highly sensitive and selective biodetection. We report a single disposable chip which is capable of carrying out a multi-step process that employs nanoparticles--a bio-barcode assay (BCA) for single protein marker detection. To illustrate the capability of the system, we tested for the presence of prostate specific antigen (PSA) in buffer solution and goat serum.

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The recently developed bio-bar-code assay for the PCR-less detection of protein and nucleic acid targets has been shown to be extraordinarily sensitive, exhibiting low attomolar sensitivity for protein targets and high zeptomolar sensitivity for nucleic acid targets. In the case of DNA detection, the original assay relies on three distinct oligonucleotide strands on a single nanoparticle for target identification and signal amplification. Herein, we report the development of a new nanoparticle probe that can be used in the bio-bar-code assay, which requires only one thiolated oligonucleotide strand.

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Background: Advances in nanoscience are having a significant impact on many scientific fields and are resulting in the development of a variety of important technologies. This impact is particularly large in the field of biodiagnostics, where a number of nanoparticle-based assays have been introduced for biomolecular detection, with DNA- or protein-functionalized gold nanoparticles used as the target-specific probes.

Methods: Assays provide an analysis of the unique biophysical properties displayed by gold nanoparticles and have advantages over conventional detection methods (e.

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The recently developed ultrasensitive bio-barcode assay was used to measure the concentration of amyloid-beta-derived diffusible ligands (ADDLs), a potential soluble pathogenic Alzheimer's disease (AD) marker, in the cerebrospinal fluid (CSF) of 30 individuals. ADDL concentrations for the subjects diagnosed with AD were consistently higher than the levels in the CSF taken from nondemented age-matched controls. Studies of ADDLs or for any other potential pathogenic AD markers in CSF have not been possible because of their low concentration in CSF (<1 pM).

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Article Synopsis
  • The study focuses on how electrons move through polymer films made of gold nanoparticles (MPCs) by a process called electron hopping, facilitated by surrounding molecular linkers.
  • An electrochemical method is introduced to measure the rates of electron hopping in these films, which are applied to a specific electrode setup involving a redox species called decamethylferrocene.
  • Results show that the apparent electron hopping rates depend on factors like concentration, film thickness, electrode potential, and temperature, falling within the range of 10^4 to 10^5 s^(-1), and are slower than the rates observed in dry films.
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The nucleation-growth-passivation Brust reaction has been modified so as to enrich the product in useful quantities of a 38-atom gold nanoparticle coated with a hexanethiolate monolayer. Two modifications are described, using -78 degrees C reduction temperature and a hyperexcess of thiol. Compositional evidence is presented that establishes the product as a Au38(C6)24 hexanethiolate monolayer protected cluster (MPC), based on transmission electron microscopy, laser ionization-desorption mass spectrometry, thermogravimetric analysis, and elemental analysis.

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