Electrodeposited copper thiocyanate (CuSCN) thin films and nanowires have been investigated by X-ray photoelectron spectroscopy (XPS), Raman and optical spectroscopy. In addition, atomic force microscopy (AFM), together with scanning and transmission electron microscopy (SEM, TEM), have been employed for structural characterisation. The multiple technique approach allows the correlation between structural, chemical and electrical properties that are unique to the structure of this material. It has been found that CuSCN thin films and nanowires exhibit high crystalline quality with a close to stoichiometric composition. The XPS and Raman spectra suggest that the thiocyanate ion is bound to copper mainly through its Send , with approximately 12-14 % bound via the N-end. The applied absorption spectroscopy (Tauc and Urbach plots) points towards the possible coexistence of two large band gaps for the electrodeposited CuSCN. While its interpretation may be problematic from a purely physical perspective, we believe that this is a direct consequence of the occurrence of two CuSCN domains identified by XPS and Raman. A prominent absorption tail is observed that is assigned as either being due to the high concentration of the traps, or a result of coexisting CuSCN domains. This absorption tail should not be an obstacle for the use of the copper thiocyanate in electronic devices, as the traps density could be reduced by annealing. In addition, non-annealed electrodeposited CuSCN thin films and nanowires of this type have recently been integrated into polymer solar cells and high efficiency has been obtained.

Translating Raman spectroscopy for colorectal cancer diagnosis with a focus on high-throughput design, inter-user variability and sample handling considerations.

A generic electrochemical method of "bioreceptor" antibody attachment to phenyl amine functionalised graphitic surfaces is demonstrated. Micro-channels of chemically modified multi-layer epitaxial graphene (MLEG) have been used to provide a repeatable and reliable response to nano molar (nM) concentrations of the cancer risk (oxidative stress) biomarker 8hydroxydeoxyguanosine (8-OHdG). X-ray photoelectron spectroscopy, Raman spectroscopy are used to characterize the functionalised MLEG. Confocal fluorescence microscopy using fluorescent-labelled antibodies indicates that the anti-8-OHdG antibody selectively binds to the phenyl amine-functionalised MLEG's channel. Current-voltage measurements on functionalised channels showed repeatable current responses from antibody-biomarker binding events. This technique is scalable, reliable, and capable of providing a rapid, quantitative, label-free assessment of biomarkers at nano-Molar (less than 20 nM) concentrations in analyte solutions. The sensitivity of the sensor device was investigated using varying concentrations of 8-OHdG, with changes in the sensor's channel resistance observed upon exposure to 8-OHdG. Detection of 8-OHdG concentrations as low as 0.1ng/ml

Understanding the role of defects in graphene is the key to tailoring the properties of graphene and promoting the development of graphene-based devices. Defects can affect the electronic properties of a device while also offering a means by which to functionalize the local properties. Using tip-enhanced Raman spectroscopy (TERS), heightened defect sensitivity was demonstrated on graphene edges, folds, and overlapping regions. Measurements confirm that TERS can provide simultaneous structural and spectral information on a localized scale, hence offering defect characterization on a scale that is not obtainable using conventional Raman spectroscopy. This study observed preferential enhancement of the D band signal on multilayered graphene and ultrathin graphite; in addition, other key defect signatures were also enhanced and detected. We present our findings in relation to theoretical predictions of graphene defect signatures and an analysis of the sensitivity of TERS in measuring two-dimensional structures.

Adsorption of functional groups to the surface of plasmonic nanoparticles provides a platform for localised optical sensing. Over the past decade, nanoscale sensors for intracellular pH measurement based on surface-enhanced Raman spectroscopy (SERS) have been developed. However, the approaches by which pH-SERS measurements are made and analysed can greatly impact the precision and accuracy of pH calibration. To improve pH nanosensors, the sources of experimental variation must be determined and the data must be optimally analysed. Here we report the plasmon-induced decarboxylation of para-mercaptobenzoic acid (pMBA) pH reporters attached to gold nanoparticles and conclude a strong association with laser power. The detrimental decarboxylation of pMBA has profound implications on the sensitivity and reliability of the pH sensor. Decarboxylation spectral signatures map directly onto those that are typically used to record pH changes, and, hence, the greatest implication of decarboxylation of pH sensors is inaccurate or false pH reporting. Here a more robust spectral analysis for pH sensing based upon an optimal spectral region for pH calibration is presented together with a unique application of the multivariate statistical technique, principal component analysis (PCA). PCA interprets complex spectral dynamics, and by direct comparisons with the typically employed ratiometric analysis, a significant improvement in generating accurate pH sensing is demonstrated. An application of these methods in determining the pH of internalised nanosensors in macrophage cells further promotes these step changes in pH measurement methodology via the avoidance of disruptive spectral signatures that arise in real applications.