Preparation of novel optical fibre-based Cocaine sensors using a molecular imprinted polymer approach

Novel chemical sensors using fibre optic-based techniques for the detection of Cocaine have been developed, utilising molecularly imprinted polymers (MIPs) containing fluorescein moieties as the signalling groups. The fluorescent MIPs were formed and covalently attached to the distal end of specially chosen optical fibres to create fibre optic probe-based sensors. These sensors exhibited are producible and quantifiable change in the intensity of the fluorescence signal received from the sensor in response to Cocaine in aqueous acetonitrile mixtures. High selectivity for Cocaine over Codeine and a range of known Cocaine interferants has been demonstrated for one of the sensors developed in this work

Development of a sensor for acetic acid based on fusarium solani

Electrochemical biosensors have become very important tools in analytical chemistry because of their advantages like accuracy, high sensitivity and easy handling. This article describes electrochemical detection of acetic acid based on the fungus Fusarium solani. The biosensor employed for the study of assimilation of substrates was fabricated by coupling the immobilized membrane with the DO probe using dialysis tubing. A microbial dispersion containing 0.2 g of wet weight of the organisms per mL was used for immobilization upon cellulose nitrate membrane. The membrane retaining the fungus was placed on the Teflon membrane of the oxygen electrode so that the fungus was trapped between the two membranes. The linear range was found to be between 2 and 70 ppm (v/v) of acetic acid. A polypropylene net increases the lifetime of the sensor due to its retention of humidity in the net. By dipping the electrochemical probe onto buffer (pH 7.2), the sensor was found to have an extended lifetime of 120 days with about 800 determination

Voltammetric studies of aspergillus niger. Assessment of their growth using electroactive extracellular production of metabolite

Large number of biochemical activities and electron behavior have a very close relationship with life forms and living cells [1], which makes the study of physiological and biochemical characteristics an important area in analytical chemistry. In recent years, researchers have developed rapid methods of assessment of cell proliferation [2–3], including reports on methods involving ATP bioluminescence [4], antibody-direct epifluorescent filter technique [5], enzyme immunoassays [6, 7], polymerase chain reaction [8], resonant mirror biosensor [9], quartz crystal microbalance biosensor [10], dielectric measurement [11], electron transfer in protein [12], and the electric impedance sensing systems [13]. The applications of direct voltammetry of cell cultures in the detection of viable microbes in biological samples have been reported [14–16]. Recent research has demonstrated that the live microbes, Tetrahymena shanghaiensis [17] and the Saccharomyces cerevisiae [18], could be monitored using cyclic voltammetry (CV). An attempt has been made here to extend this for fungal strains. The conventional method of the studies on the growth phases of fungi is cumbersome and time consuming because the time period required for the growth of the fungi is in terms of days, while for bacterial strains, all the phases of growth are completed in a few hours. This manuscript discusses the voltammeric behavior of the fungus, Aspergillus niger that was isolated from polyurethane waste scraps

The family Donacidae (Bivalvia: Tellinoidea) in Thai waters

The species belonging to the family Donacidae living in Thailand waters are herein revised. After an exhaustive bibliographical search, 29 nominal species were found from this area. Materials from several institutions and specimens collected during fieldwork in Phuket and the Gulf of Thailand were studied. All the type materials were illustrated and redescribed. Details of the type localities, repositories, habitats and biogeographical distribution are discussed. In addition, some collected specimens and the type materials of the valid species and synonyms are illustrated. Currently, eight valid species are confirmed as living in Thailand waters: Donax (Deltachion) spinosus Gmelin, 1791, Donax (Deltachion) semigranosus (Dunker, 1877), Donax (Dentilatona) incarnatus Gmelin, 1791, Donax (Hecuba) scortum (Linnaeus, 1758), Donax (Latona) cuneatus Linnaeus, 1758, Donax (Latona) faba Gmelin, 1791, Donax (Latona) solidus Spengler, 1798 and Donax (Paraserrula) introradiatus Reeve, 1855. The presence of Donax (Deltachion) semisulcatus Hanley, 1843, Donax brazieri Smith, 1892, Donax (Tentidonax) veruinus Hedely, 1913 and Donax victoris Fischer-Piette, 1942 in Thailand waters remains uncertain. These species have been reported in the study area in the literature, but they were not sampled during this study.Fil: Signorelli, Javier Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Printrakoon, Cheewarat. Kasetsart University; Tailandi