ORCID Profile
0000-0002-5481-1066
Current Organisation
Trinity College Dublin
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Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1SC01236C
Abstract: Exploration of potential-dependent, multi-colour co-reactant electrochemiluminescence from multiple luminophores at the working and counter electrodes reveals new pathways to emission.
Publisher: IEEE
Date: 2000
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CC03201K
Abstract: Monitoring emission and potentials at both the working and counter electrodes provides new insight into a proposed cathodic electrochemiluminescence system.
Publisher: Springer Science and Business Media LLC
Date: 04-05-2016
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.FORSCIINT.2015.03.014
Abstract: Current histological investigation of vaginal swabs after alleged sexual assault includes the scoring of spermatozoa (0, + to ++++) and the recording of visible tails. It is a method that is universally employed. Despite this method being used for 40 years, there has never been a study investigating its suitability for forensic science. Here, we investigate the reproducibility and subjectivity of sperm scoring among different investigators. Dilutions of seminal fluid were randomly distributed onto 20 slides, stained with haematoxylin/eosin and assessed by 37 investigators, over 2 years. Slides were assessed for levels of spermatozoa and the presence of tails. Each slide was scored by a minimum of 25 investigators. On no slide was there a consensus between all scores. Standard deviation remained below 1, but relative standard deviation (RSD) ranged from 6 to 105% in a positive correlation as the average score decreased. Spermatozoa were not observed 56 times (9.6%) and 27 investigators (73%) did not observe spermatozoa on at least one slide. Spermatozoa with tails were observed on every slide by at least 10 examiners, but as the average score of the slide decreased, so did the observation of tails. The current sperm scoring method is highly subjective with a particularly high %RSD in slides with low overall sperm counts. Moreover, the recording of tails does not add value to the current technique of sperm scoring. Further research might improve the objectivity of sperm scoring and the reliability of recording of tails.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JAIP.2019.09.008
Abstract: Guidelines recommend that patients treated with inhalers receive adherence counseling and device training. Digital technologies that assess both inhaler adherence and technique have been developed. Using these technologies community pharmacists, who have regular contact with patients, are well placed to deliver personalized inhaler education. To determine the impact of a pharmacist intervention, informed by digital technology, on inhaler technique and adherence of patients with asthma in the community. A cluster randomized, parallel-group, multisite pharmacy study was conducted over 6 months. All study groups had an electronic device (inhaler compliance assessment device) attached to their maintenance inhaler. A biofeedback group received personalized inhaler training informed by data recorded by the device. The demonstration group received inhaler training, by physical demonstration with a placebo inhaler. The control group received usual care. The primary outcome was inhaler adherence, which was classified as "actual adherence" and expressed as the proportion of expected drug accumulation if adherence and technique had been perfect. Secondary outcomes were quality-of-life scores as measured by the St George's Respiratory Questionnaire, symptoms, and exacerbations. A total of 152 participants (n = 74 biofeedback, n = 56 demonstration, and n = 22 control) were recruited. Asthma was the predominant condition among participants (n = 83), with chronic obstructive pulmonary disease (n = 55) and asthma/chronic obstructive pulmonary disease overlap also reported (n = 8). In intention-to-treat analysis, adherence in the biofeedback group during month 2 was 62%, 18% higher (95% CI, 6 to 30) than that in the demonstration group (P = .004) and 24% higher (95% CI, 9 to 40) than that in the control group (P = .003). During month 6, adherence was 14% higher (95% CI, -1 to 30 P = .07) in the biofeedback group than in the demonstration group and 31% higher (95% CI, 13 to 48 P = .001) than in the control group. At the end of the study, the biofeedback group had a sustained fall in St George's Respiratory Questionnaire from baseline, -6.1 (95% CI, -9 to -0.4 P = .04) and had significantly improved daily respiratory symptoms. Community pharmacist-delivered inhaler training informed by a digital technology improved adherence and health status.
Publisher: Public Library of Science (PLoS)
Date: 04-01-2016
Publisher: American Chemical Society (ACS)
Date: 18-03-2011
DOI: 10.1021/JA1114634
Abstract: An electroactive nitrospiropyran-substituted polyterthiophene, poly(2-(3,3''-dimethylindoline-6'-nitrobenzospiropyranyl)ethyl 4,4''-didecyloxy-2,2':5',2''-terthiophene-3'-acetate), has been synthesized for the first time. The spiropyran, incorporated into the polymer backbone by covalent attachment to the alkoxyterthiophene monomer units, leads to multiple colored states as a result of both photochemical and electrochemical isomerization of the spiropyran moiety to merocyanine forms as well as electrochemical oxidation of the polyterthiophene backbone and the merocyanine substituents. While electrochemical polymerization of the terthiophene monomer can take place without oxidation of the spiropyran, increasing the oxidation potential leads to complex electrochemistry that clearly involves this substituent. To understand this complex behavior, the first detailed electrochemical study of the oxidation of the precursor spiropyran, 1-(2-hydroxyethyl)-3,3-dimethylindoline-6'-nitrobenzospiropyran, was undertaken, showing that, in solution, an irreversible electrochemical oxidation of the spiropyran occurs leading to reversible redox behavior of at least two merocyanine isomers. With these insights, an extensive electrochemical and spectroelectrochemical study of the nitrospiropyran-substituted polyterthiophene films reveals an initial irreversible electrochemical oxidative ring-opening of the spiropyran to oxidized merocyanine. Subsequent reduction and cyclic voltammetry of the resulting nitromerocyanine-substituted polyterthiophene film gives rise to the formation of both merocyanine π-dimers or oligomers and π-radical cation dimers, between polymer chains. Although merocyanine formation is not electrochemically reversible, the spiropyran can be photochemically regenerated, through irradiation with visible light. Subsequent electrochemical oxidation of the nitrospiropyran-substituted polymer reduces the efficiency of the spiropyran to merocyanine isomerization, providing electrochemical control over the polymer properties. SEM and AFM images support the conclusion that the bulky spiropyran substituent is electrochemically isomerized to the planar merocyanine moiety, affording a smoother polymer film. The conductivity of the freestanding polymer film was found to be 0.4 S cm(-1).
Publisher: Springer Science and Business Media LLC
Date: 10-11-2016
DOI: 10.1007/S00414-016-1461-X
Abstract: Sexual assault s les are some of the most common s les encountered in forensic analysis. These s les can require a significant time investment due to differential extraction processes. We report on the first record of successful direct lification of semen for STR analysis. Neat seminal fluid, dilutions ranging from 1:5 to 1:160 and GEDNAP s les were successfully lified using a direct method. A mild differential isolation technique to enrich spermatozoa was developed and successfully implemented to separate and directly lify a mixture of semen and female epithelial cells. Aliquots of s les subjected to the differential isolation protocol were stained with Haemotoxylin and Eosin for sperm scoring. S les stained after PCR showed a complete lack of intact spermatozoa demonstrating that the cells are lysed during the PCR process. This paper demonstrates the potential to incorporate direct PCR in cases of sexual assault to more rapidly obtain results and achieve a higher sensitivity.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0CP00699H
Abstract: The properties of two forms of polyaniline (PAni) synthesised under acidic and basic conditions have been investigated both in idually and as combined complexes. The PAni polymerised within alkaline media was redox inactive and non-conducting while the PAni emeraldine salt (ES) was electroactive and conducting. Raman, electron spin resonance, UV-Vis and fluorescence spectroscopies were used to monitor the changes in electronic properties of these conducting polymer composites. Solution cast films of alkaline synthesised (A-PAni) with the PAni ES resulted in an increase in the high spin polaron population suggesting that it acts as a pseudodopant. The ability of the A-PAni to increase and maintain the population of the polaron charge carrier was confirmed by UV-vis and Raman spectroscopy. Significantly, the presence of the A-PAni in PAni ES helped to sustain higher electrical conductivities at loading levels that were well below the percolation threshold of an insulating polystyrene sulfonate polymeric oligomer model. Fluorescence studies indicated that the A-PAni was fluorescent. However, mixtures of A-PAni with the PAni ES resulted in quenching of the A-PAni emission. The quenching process was observed to involve both static and dynamic processes, with the static quenching being dominant. These results suggest that the two polymers are strongly associated with each other when in the solid state. In stark contrast, the alkaline synthesized PAni did not influence the electrochemical properties of the emeraldine salt. These results deviate significantly from the expected outcome of the addition of an insulating A-PAni additive and highlight the unusual interactions occurring between PAni and its alkaline analogue.
Publisher: American Chemical Society (ACS)
Date: 26-01-2006
DOI: 10.1021/AC0513919
Abstract: The effect of surface confinement on the electrochemiluminescence (ECL) properties of metallopolymer [Ru(bpy)2(PVP)10]2+, where bpy is 2,2'-bipyridyl and PVP is poly(4-vinylpyridine), is reported. Immobilizing a luminescent material on an electrode surface can substantially modulate its photophysical properties. Significantly, our study revealed that the overall efficiency of the ECL reaction for the metallopolymer film is almost four times higher, at 0.15%, than the highest value obtained for [Ru(bpy)2(PVP)10]2+ dissolved in solution, (phi(ECL) = 0.04%). Electrochemistry has been used to create well-defined concentrations of the quencher Ru3+ within the film. Analysis of both the steady-state luminescence and lifetimes of the film reveals that static quenching by electron transfer between the photoexcited Ru2+ and the Ru3+ centers is the dominant quenching mechanism. The bimolecular rate of electron transfer is (2.5 +/- 0.4) x 10(6) M(-1) s(-1). The implications of these findings for ECL-based sensors, in terms of optimum luminophore loading, is considered.
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B923921A
Abstract: The use of nanostructured carbon materials as electrodes for energy storage and conversion is an expanding area of research in recent years. Herein, platinum nanoparticles have been deposited onto both multi-walled and single-walled carbon nanotubes (CNTs) via a microwave assisted polyol reduction method. This interaction has been probed with electron paramagnetic resonance (EPR) and Raman spectroscopies to elucidate the charge/electron transfer interactions between the Pt nanoparticles and the CNTs. Observed shifts in the g factors of the CNTs are indicative of such an electronic interaction, strongly suggesting the covalent attachment of the nanoparticles to the carboxylic groups on the CNTs, formed during the microwave-assisted reduction process. The Pt decorated CNTs show a dramatic increase in electrochemical behaviour in terms of high reversible capacity and relatively stable cycle performance compared to unmodified CNTs increasing their applicability in energy storage devices. For instance, significant increases in the electrochemical double layer capacitance are observed for the CNT-NP composite electrode.
Publisher: American Chemical Society (ACS)
Date: 14-07-2009
DOI: 10.1021/LA901661V
Abstract: The electrochemical and photophysical properties of a luminescent metal center, [Os(bpy)(3)](2+), are significantly modified by encapsulation within a conducting polymer composite film. Cyclic voltammetry reveals that the encapsulation in an inherently conducting polymer, polyaniline (Pani) or polypyrrole (PPy), can dramatically influence the charge-transfer rates between the metal centers. The increased electron transport, most likely mediated through the conducting polymer backbone, significantly enhances the electrochemiluminescence (ECL) efficiency. The increased communication between adjacent metal centers can also result in other interesting properties, such as photoinduced electron-transfer processes. In situ electron spin resonance (ESR) spectroscopy has been used to probe the photo-oxidation of an osmium metal center encapsulated in a PPy composite film. The irradiation of PPy in the presence of the osmium metal center resulted in the photo-oxidation of the Os(2+) to Os(3+) state and the consequent reduction of the PPy polyelectrolyte. The degree of communication between luminescent metal centers allows the composite properties to be tuned for various applications including ECL sensor devices and light-switching and light-harvesting systems.
Publisher: American Chemical Society (ACS)
Date: 24-09-2008
DOI: 10.1021/JP804213R
Abstract: In situ electron spin resonance (ESR) studies have been performed on composite films consisting of a ruthenium tris(bipyridyl) complex and an inherently conducting polymer, poly(2-methoxyaniline-5-sulfonic acid) (PMAS). The composites were investigated under white light irradiation and potential control conditions to probe photoinduced electron transfer between the ruthenium metal center and the conducting polymer. PMAS exhibited a clear ESR signal, characteristic of the presence of mobile single spin polarons within the polymer structure. Irradiation of the PMAS in the presence of the ruthenium metal center resulted in the photo-oxidation of the Ru (2+) to the Ru (3+) state, as a result of which the PMAS ESR signal was replaced by a response typical of the Ru (3+) salt. Upon removal of the illumination, reversible photo switching occurred. This reversibility makes these novel composites promising for applications in areas such as chemical sensors, light switching, and light harvesting devices.
Publisher: Elsevier BV
Date: 07-2010
Publisher: Proceedings of the National Academy of Sciences
Date: 23-11-2020
Abstract: Proponents of the altered states of consciousness (ASC) model have argued that hallucinogens have influenced the prehistoric making of images in caves and rock shelters. However, the lack of direct evidence for the consumption of hallucinogens at any global rock art site has undermined the ASC model. We present the first clear evidence for the ingestion of hallucinogens at a rock art site, in this case, from Pinwheel Cave, California. Quids in the cave ceiling are shown to be Datura wrightii , a Native Californian entheogen, indicating that, rather than illustrating visual phenomena caused by the Datura , the rock paintings instead likely represent the plant and its pollinator, calling into question long-held assumptions about rock art and the ASC model.
Publisher: American Chemical Society (ACS)
Date: 05-2009
DOI: 10.1021/JP901808D
Abstract: Steady state luminescence and measurements of the luminescent lifetime as well as cyclic voltammetry have been used to elucidate the mechanism and dynamics of interaction between a luminescent ruthenium metal center and two different fractions of poly(2-methoxyaniline-5-sulfonic acid) (PMAS). The two fractions, high molecular weight (HMWT) PMAS and low molecular weight (LMWT) PMAS oligomer, showed significantly distinctive influences on the luminophore. The HMWT PMAS, confirmed to be an emeraldine salt by its characteristic redox chemistry, greatly impacted the diffusion coefficient of the Ru2+/3+ within the composite film, increasing the diffusion coefficient, DCT, by 2 orders of magnitude. The HMWT PMAS also resulted in quenching of the ruthenium-based emission. Significantly, these results indicate that quenching involves both static and dynamic processes, with the static quenching being the dominant process, suggesting that the metal center and polymer backbone were strongly associated. In stark contrast, the LMWT PMAS did not influence the electrochemical properties of the ruthenium metal center however, it did double the emission observed from the ruthenium metal center. The insensitivity of the luminescence lifetime does suggest that, as with the HMWT PMAS, LWMT PMAS is strongly associated with the ruthenium metal center. The enhanced luminescence may allow for many potential sensor developments based on the luminescent ruthenium metal center, while the HMWT PMAS quenching could be utilized within quenching-based strategies or electrochemical devices.
Publisher: Royal Society of Chemistry (RSC)
Date: 2009
DOI: 10.1039/B909709K
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA08450D
Abstract: The stepwise fabrication of the sensor is highlighted, scFv immobilization, binding of pentameric CRP followed by binding of metal labeled scFv fragments.
Publisher: Elsevier BV
Date: 05-2008
Publisher: The Electrochemical Society
Date: 23-11-2020
DOI: 10.1149/MA2020-02582881MTGABS
Abstract: Rapid and continuous appearance of novel psychoactive substances (NPS) onto the global drug market has highlighted the significant requirement for new and alternative screening methodologies. Current screening protocols, primarily consisting of the colorimetric NIK® tests, are not only inadequate for NPS but they are not compatible with any matrix other than the pure drug product. Here we discuss the potential power of electrochemiluminescence (ECL) as a simple tool for drug screening. The intrinsic advantages of ECL make it an ideal candidate as an alternative analytical technique for the rapid identification of drug species, within a range of complex matrices. NPS, often contain a mixture of substances, while analysis of complex matrices can be challenging due to a number of potential interfering species present. Traditional ECL systems typically employ a single ruthenium based luminophore. This single complex approach often prevents the successful differentiation of structurally similar compounds, which typically interact with the complex via analogous mechanisms producing emission within the same potential regions. Multiplexed sensors utilising several different metal luminophores as well as pH controlled emission offer viable mechanisms to tackle the limited specificity associated with ECL techniques. Utilising tropane alkaloids, atropine and scopolamine as model compounds, a straightforward ECL sensor based upon a portable screen printed electrode set up, offering rapid results at minimal cost in a variety of complex matrices has been developed. The sensors portability matches that of current screening protocols but utilises less hazardous materials and removed subjectivity. Two alternative methodologies to improve the specificity offered by ECL were investigated within this study. By exploiting the relationship between pH and ECL emission the ability to differentiate between the two structurally similar species, upon a simple ruthenium based sensor, such as shown in Figure 1, is possible. The use of pH controlled ECL, allows for emission from one species to be “switched off” within a mixed s le. With knowledge of the target species pKa this methodology can be used to tailor the sensor toward a variety of species, offering improved specificity without having to alter sensor fabrication. The employment of different metal luminophores, such as iridium and osmium, can offer the possibility to increase specificity, with different selectivity offered by each luminophore. By using a combination of different metal luminophores the ability to differentiate between structurally similar species becomes possible, something currently not attainable when utilising a single luminophore system. Furthermore, the opportunity to negate previously encountered interference effects due to matrix composition becomes viable. By utilising a combination of different metal complexes we have successfully demonstrated the ability to effectively negate the interference effect from naturally occurring amino acids present in biological matrices such as human serum, a previously noted limitation for the use of ECL within biological matrices. Here we provide a strong proof-of-concept for the development of multiplexed ECL sensors, utilising several luminophores to tackle the limited specificity currently offered by ECL. By tackling this limitation, the potential applications of current ECL based sensors could be expanded significantly. Whats more our sensor design offers the ability to analyse a variety of complex biological matrices without the requirement of s le preparation. The potential to utilise one portable technique for drug screening across a variety of matrices, with the ability to tailor emission toward a specific drug species, without the requirement of a full lab facility will not only benefit the wider sensing community but such sensors offer the potential to reduce cost, increase throughput and simplify drug screening procedures in a variety of fields. Finally, a key challenge of electroanalytical sensors is multiplexed detection and this study will facilitate understanding of ECL based sensors to overcome this hurdle. Figure 1
Publisher: IEEE
Date: 2000
No related grants have been discovered for Lynn Dennany.