Ciara K O'Sullivan

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The current work describes the optimisation of a screen-printed electrode (SPE) system for measurement of a variety of seafood toxins, such as okadaic acid, brevetoxin, domoic acid and tetrodotoxin. A disposable screen-printed carbon electrode coupled with amperometric detection of p-aminophenol at +300 mV vs. Ag/AgCl, produced by the label, alkaline(More)
Aptamers are synthetic oligonucleotides specifically selected to bind a certain target. Thanks to their high affinity and sensitivity, aptamers appear as alternative candidates to antibodies for analytical devices and several assays have been reported. However, and contrary to what happens with DNA probes, the aptamers' ability to bind their targets depends(More)
A novel impedimetric aptasensor using a mixed self-assembled monolayer composed of thiol-modified thrombin binding aptamer and 2-mercaptoethanol on a gold electrode is reported. The changes of interfacial features of the electrode were probed in the presence of the reversible redox couple, Fe(CN)6(3-/4-), using impedance measurements. The electrode surface(More)
Aptamers are artificial nucleic acid ligands that can be generated against amino acids, drugs, proteins and other molecules. They are isolated from combinatorial libraries of synthetic nucleic acid by an iterative process of adsorption, recovery and reamplification. Aptamers, first reported in 1990, are attracting interest in the areas of therapeutics and(More)
Immense effort has been placed on the realization of immunoassays exploiting displacement of a suboptimum target, due to the ease of use and applicability to immunochromatographic strips and immunosensors. Most of the efforts reported to date focus on the use of a suboptimal target that is displaceable by the target toward which the antibody has higher(More)
The determination of antigliadin antibodies from human serum samples is of vital importance for the diagnosis of an autoimmune disease such as celiac disease. An electrochemical immunosensor that mimics traditional ELISA type architecture has been constructed for the detection of antigliadin antibodies with control over the orientation and packing of(More)
Detection of proteins that signal the presence or recurrence of cancer is a powerful therapeutic tool for effective early diagnosis and treatment. Carcinoembryonic antigen (CEA) has been extensively studied as a tumor marker in clinical diagnosis. We report on the development of an amperometric biosensor for the detection of CEA based on the immobilization(More)
Currently, prostate-specific antigen (PSA) is considered to be the most sensitive marker available for prostate cancer detection and for monitoring of disease progression. In addition to its importance as a tumor marker, PSA has a role in the biological activity of cancer growth and proliferation. Therefore, the inhibition or activation of its biological(More)
This report highlights the characteristics of an okadaic acid immunoassay with limits of detection in the subfemtomole range. Two different immunoassay formats were investigated and their characteristics compared in relation to linear ranges, limits of detection, and cross-reactivity with other seafood toxins present in water and/or mussel samples. The(More)
Aptamers are artificial nucleic acid ligands, specifically generated against certain targets, such as amino acids, drugs, proteins or other molecules. In nature they exist as a nucleic acid based genetic regulatory element called a riboswitch. For generation of artificial ligands, they are isolated from combinatorial libraries of synthetic nucleic acid by(More)