A series of benzothiazole heptamethine cyanine dyes have been synthesized and their photophysical properties evaluated in relation to their structural features. These have been compared against two classical probes of this type: Indocyanine Green (IGC) and New Indocyanine Green (IR-820). Growth inhibitory studies were also performed using a eukaryotic, unicellular organism, fission yeast Schizosaccharomyces pombe. Herein we highlight some potentially interesting candidates with improved fluorescence quantum yields when compared with ICG and IR-820.

The interaction between various novel naphthoquinones and glutathione was explored using a variety of electrochemical techniques. An adamantane derivatised quinone was found to adsorb strongly to carbon surfaces providing a robust film possessing a distinct and consistent voltammetric profile which is markedly different from solution based species. The anodic peak process was found to respond to increasing additions of glutathione and the analytical merits have been assessed. In contrast to conventional thiol–quinone electrochemistry, the detection pathway involves the solubilisation and removal of the hydrophobic quinone derivative through conjugation with glutathione. The peak potential (+0.2 V vs. Ag/AgCl) is such that an unambiguous response to glutathione can be achieved in the presence of a significant excess (1 mM) of common physiological components.

Conductive microneedle patches consisting of carbon nanoparticles embedded in a polystyrene matrix have been prepared using micro-moulding techniques. The interfacial properties of the structures before and after electrochemical etching have been characterised using X-ray photoelectron spectroscopy and contact angle. Anodisation of the needles leads to a significant increase in oxygen functionality and is shown to dramatically improve the electroanalytical capabilities of the microneedle array. The detection of uric acid in horse blood was used as a model system through which to assess the performance of the system. The composite approach is shown to lead to viable carbon-based sensors and can offer a rapid prototype option for the development of tailored microneedle systems.