Development and characterization of novel biosensors utilizing plant tissue materials and intact chemoreceptor structures

Abstract

A biosensor is defined as a device which incorporates a biological component which is either intimately connected to or integrated within a transducer. Plant tissue materials and intact chemoreceptor structures are utilized as molecular recognition elements to construct biosensors with selectivity for various important analytes. The use of grape tissue as a source of catalase for the determination of hydrogen peroxide was demonstrated. A slice of grape tissue attached to the membrane of a Clark-type oxygen sensor was used to monitor the oxidation of hydrogen peroxide by catalase. Characterization of the novel sensor in terms of selectivity, sensitivity, reproducibility, linear response range and lifetime is reported. The use of pea seedlings as a source of diamine oxidase for the determination of enzymatic oxidation rates, which are important in evaluating the plant growth-regulating activity, of various amines was investigated. A mixed carbon paste-plant tissue amperometric sensor was constructed and characterized using spermidine as a substrate. Generation of hydrogen peroxide due to enzymatic oxidation of the amine was monitored at 0.9 V vs. Ag/AgCI under steady-state conditions using this sensor. Easy construction, reliability of the data, reusability and shorter response times are some of the advantages of this sensor. Receptor-based biosensors using chemosensing structures from fresh-water species (crayfish) are shown to give selective analytical responses to the antitubercular drug, pyrazinamide. The frequency of action potential responses evoked by chemical stimulation of nerve cells was measured using a conventional electrophysiological technique. The construction of such biosensors, in general, is facilitated through the use of a video imaging inverted biological microscope during the manipulation and assembly of the delicate structures involved. Characterization of the novel sensor in terms of selectivity, sensitivity, response time, dose/response relationship, and lifetime is reported. The advantages of using fresh-water versus salt-water species in constructing neuronal biosensors are also discussed. A reusable neuronal sensor selective to the neurotoxin 3-acetyl pyridine was constructed by using the antennular structure from crayfish. Reusability of the sensor was studied with emphasis on the reproducibility of action potential responses. Characterization of the novel sensor in terms of selectivity, response time and dose/response relationship is reported. The current status of attempts at lifetime extension of neuronal biosensors are discussed.