Electroanalytical analysis of phenol oxidation using bacteria immobilized by a polycaprolactone coating on the copper electrode surface.

The copper electrode modified by bacteria immobilised by a polycaprolactone film was successfully developed by electropolymerisation for the purpose of determining the presence of phenol. Electrochemical techniques such as square-wave voltammetry (SWV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the electrochemical properties of the Cu-polymer/bacteria electrode. The results show that the intensity of the phenol oxidation peak increases with concentration, allowing us to obtain good analytical results with DL of 2.156 × 10-7 M and QL which is 7.2 × 10-7 M , confirming that the biosensor has excellent electroanalytical activity for phenol oxidation, with good stability and a wide linear range. Our electrode is based on a easily available and inexpensive material, as well as on its simple preparation, which has demonstrated high performance for phenol.

Recent advances in electrochemical sensors and biosensors for monitoring drugs and metabolites in pharmaceutical and biological samples.

Various applications of electrochemical sensors and biosensors have been reported in many fields. These include pharmaceuticals, drug detection, cancer detection, and analysis of toxic elements in tap water. Electrochemical sensors are characterised by their low cost, ease of manufacture, rapid analysis, small size and ability to detect multiple elements simultaneously. They also allow the reaction mechanisms of analytes, such as drugs, to be taken into account, giving a first indication of their fate in the body or their pharmaceutical preparation. Several materials are used in the construction of sensors, such as graphene, fullerene, carbon nanotubes, carbon graphite, glassy carbon, carbon clay, graphene oxide, reduced graphene oxide, and metals. This review covers the most recent progress in electrochemical sensors used to analyze drugs and metabolites in pharmaceutical and biological samples. We have highlighted carbon paste electrodes (CPE), glassy carbon electrodes (GCE), screen-printed carbon electrodes (SPCE) and reduced graphene oxide electrodes (rGOE). The sensitivity and analysis speed of electrochemical sensors can be improved by modifying them with conductive materials. Different materials used for modification have been reported and demonstrated, such as molecularly imprinted polymers, multiwalled carbon nanotubes, fullerene (C60), iron(III) nanoparticles (Fe3O4NP), and CuO micro-fragments (CuO MF). Manufacturing strategies and the detection limit of each sensor have been reported.

A water soluble fluorescent BODIPY dye with azathia-crown ether functionality for mercury chemosensing in environmental media.

A novel mercury chemosensor based on water soluble fluorescent BODIPY probe with an azathia-crown ether moiety has been synthesised through condensation of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene as a fluorophore coupled at the 3-position to an azathia macrocycle via an ethenylphenyl linker. Spectroscopic properties and complex formation with several metal ions are investigated in aqueous organic solvent and in water via colorimetric and fluorometric titrations. The binding ratio of chemosensor to Hg(2+) complex was determined to be 1 : 1 according to a Job plot. Hg(2+) binding in chemosensor was 8.19 × 10(3) M(-1). The fluorescence and colorimetric spectroscopic experiments in this study demonstrated that chemosensor can be used as a fluorescent and colorimetric probe for detecting Hg(2+) in water.

Efficient double glycoconjugation to naturalize high molecular weight disperse dyes.

Commercially available Disperse Orange 29 (1a) and Disperse Red 1 (2a) were elaborated to glycoconjugated species, following a new version of a previously-described 'naturalisation' procedure. Glutamic acid was chosen to achieve a double glycoconjugation, which is essential to give to the original disperse dye a water solubility suitable for reaching optimal dyeing conditions. UV-vis plot of the 'naturalised' species showed negligible differences when compared to those of the commercial dyes.

A novel glycoconjugated N-acetylamino aldehyde hydrazone azo dye as chromogenic probe for cyanide detection in water.

A new selective chemodosimeter probe of cyanide anions in aqueous media was developed by the introduction of a simple glyco-conjugated o-(carboxamido) aldehyde hydrazone into an azo dye as chemodosimeter that recognizes cyanide anions among other competing anions such as acetate, dihydrogen phosphate, fluoride through reversible covalent bonding. The sensing properties of the new materials were investigated in pure water and have demonstrated a very high selectivity toward the cyanide anions. The detection limit of the new chromogenic probe was measured to be 1.29 µM which is much lower than most recently reported chromogenic probes for cyanide determination.

'Naturalization' of textile disperse dyes through glycoconjugation: the case of a bis(2-hydroxyethyl) group containing azo dye.

A family of five strictly related glycoconjugated azo dyes (GADs), characterized by the presence of the same chromophore and a variable number (1-4) of deprotected hexose units, has been prepared by employing succinate bridges for connecting the azo dye and the sugar portions. The modulation of the hydrophilic portion determines the appreciable changes in the water solubility of GADs. In all the cases, however, hydrophobic fibres (polyester) were homogeneously dyed with GADs at temperatures lower than that used for original azo dyes, at atmospheric pressure, and avoiding the use of surfactants. Furthermore, GADs show an interesting multipurpose character leading to dyeing well also the natural fibres as, for instance, wool. The presence of a variable number of hexose units in the different GADs determines some changes in the colour intensity of dyed fabrics, but in all the cases an appreciable rubbing and water fastness were maintained.