Elevated levels of transfer RNA (tRNA) fragments were recently identified in plasma samples from people with epilepsy in advance of a seizure, indicting a potential novel class of circulating biomarker. Current methods for detection and quantitation of tRNA fragments (tRFs) include northern blotting, RNA sequencing or custom Taqman-based PCR assays. The development of a simple, at home or clinic-based test, would benefit from a simple and reliable method to detect the tRFs using small volumes of biofluids.
View Article and Find Full Text PDFThe need for practical biomarkers for early diagnosis of Alzheimer's disease (AD) remains largely unmet. Here we investigated the use of blood-based microRNAs as prognostic biomarkers for AD and their application in a novel electrochemical microfluidic device for microRNA detection. MicroRNA transcriptome was profiled in plasma from patients with mild cognitive impairment (MCI) and AD.
View Article and Find Full Text PDFBackground: There are no blood-based molecular biomarkers of temporal lobe epilepsy (TLE) to support clinical diagnosis. MicroRNAs are short noncoding RNAs with strong biomarker potential due to their cell-specific expression, mechanistic links to brain excitability, and stable detection in biofluids. Altered levels of circulating microRNAs have been reported in human epilepsy, but most studies collected samples from one clinical site, used a single profiling platform or conducted minimal validation.
View Article and Find Full Text PDFDiagnosis of seizure disorders such as epilepsy currently relies on clinical examination and electroencephalogram recordings and is associated with substantial mis-diagnosis. The miRNA, miR-134 (MIR134 in humans), has been found to be elevated in brain tissue after experimental status epilepticus and in human epilepsy cells and their detection in biofluids may serve as unique biomarkers. miRNAs from unprocessed human plasma and human cerebrospinal fluid samples were used in a novel electrochemical detection based on electrocatalytic platinum nanoparticles inside a centrifugal microfluidic device where the sandwich assay is formed using an event triggered release system, suitable for the rapid point-of-care detection of low abundance biomarkers of disease.
View Article and Find Full Text PDFOligonucleotide hybridization to a complementary sequence that is covalently attached to an electrochemically active conducting polymer (ECP) coating the working electrode of an electrochemical cell causes an increase in reaction impedance for the ferro-ferricyanide redox couple. We demonstrate the use of this effect to measure, in real time, the progress of DNA polymerase chain reaction (PCR) amplification of a minor component of a DNA extract. The forward primer is attached to the ECP.
View Article and Find Full Text PDFSuspensions of electrocatalytic platinum nanoparticles with radii as small as 78.9 ± 3.5 nm that are functionalised with DNA only in one region have been created using templated electrodeposition.
View Article and Find Full Text PDFSelf-assembled monolayers (SAMs) of dodecanethiol have been formed on gold electrodes to produce nanoscale defects. These defects define nucleation sites for the electrodeposition of mushroom shaped platinum nanoparticles (PtNPs). The top surfaces of these PtNPs have been selectively functionalized with single stranded probe DNA.
View Article and Find Full Text PDFThe photochemistry of (η(6)-anisole)Cr(CO)(3) and (η(6)-thioanisole)Cr(CO)(3) was investigated by picosecond time-resolved infrared spectroscopy in n-heptane solution at 298 K. Two independent excited states are populated following 400 nm excitation of each of these complexes. An excited state with some metal-to-CO charge-transfer character is responsible for the CO-loss process, which is slow compared to CO-loss from Cr(CO)(6).
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