β-Cyclodextrin-Modified CdSe/ZnS Quantum Dots for Sensing and Chiroselective Analysis

β-Cyclodextrin (β-CD)-functionalized CdSe/ZnS quantum dots (QDs) are used for optical sensing and chiroselective sensing of different substrates using a fluorescence resonance energy transfer (FRET) or an electron transfer (ET) mechanisms. The FRET between the QDs and Rhodamine B incorporated in the β-CD receptor sites is used for the competitive analysis of adamantanecarboxylic acid and of p-hydroxytoluene. Also, the dye-incorporated β-CD-modified QDs are used for the chiroselective optical discrimination between d,l-phenylalanine and d,l-tyrosine. The receptor-functionalized QDs are also implemented for the optical detection of p-nitrophenol using an ET quenching route

Following the Biocatalytic Activities of Glucose Oxidase by Electrochemically Cross-Linked Enzyme−Pt Nanoparticles Composite Electrodes

An integrated platinum nanoparticles (NPs)/glucose oxidase (GOx) composite film associated with a Au electrode is used to follow the biocatalytic activities of the enzyme. The film is assembled on a Au electrode by the electropolymerization of thioaniline-functionalized Pt NPs and thioaniline-modified GOx. The resulting enzyme/Pt NPs-functionalized electrode stimulates the O2 oxidation of glucose to gluconic acid and H2O2. The modified electrode is then implemented to follow the activity of the enzyme by the electrochemical monitoring of the generated H2O2. The effect of the composition of the Pt NPs/GOx cross-linked nanostructures and the optimal conditions for the preparation of the electrodes are discussed