Piezoelectric biosensor detects seafood pathogen.Public concerns over the safety of seafood have become a significant obstacle, hindering growth of the industry. One of the most notorious types of contamination involves the pathogen V. parahaemolyticus. A simple, rapid detection technique is needed to minimize risk from this pathogen. Those same scientists at the University of Rhode Island HistoryThe University was first chartered as the state's agricultural school in 1888. The site of the school was originally the Oliver Watson Farm, and the original farmhouse still lies on the campus today. also have developed a rapid piezoelectric The property of certain crystals that causes them to produce voltage when a mechanical pressure is applied to them such as sound vibrations. This technique is used to build crystal microphones, phonograph cartridges and strain gauges, all of which turn mechanical movement into voltage. biosensor A device that detects and analyzes body movement, temperature or fluids and turns it into an electronic signal. See lab on a chip and data glove. Biosensor detection system that is specific to V. parahaemolyticus. The system combines the specificity of antibody recognition with the high sensitivity of a quartz crystal microbalance mi·cro·bal·ance n. A balance designed to weigh very small loads, up to 0.1 gram. Noun 1. microbalance - balance for weighing very small objects balance - a scale for weighing; depends on pull of gravity (QCM), which together make it possible to assay a sample almost in real time. The biosensor consists of an antibody-coated quartz crystal mounted in a flow cell. Researchers built a flow-injection analysis system. In tests, they immobilized anti-V. parahaemolyticus antibodies on the gold electrode of a 5 Mhz piezoelectric quartz crystal using a protein A coupling technique or polyethyleneimine adhesion with chemical crosslinking. A reaction of the protein-coupled biosensor with live cells of the bacteria produced a 19 Hz to 80 Hz decrease in frequency in 20 min. This corresponded to concentrations of up to 10(7) CFU/ml. The system with the adhesion and crosslinking technique yielded up to a 47 Hz decrease in frequency in 20 min, with same concentrations of bacteria. It appears that the protein-coupling approach is the best immobilization Immobilization Definition Immobilization refers to the process of holding a joint or bone in place with a splint, cast, or brace. This is done to prevent an injured area from moving while it heals. method. Scientists were able to regenerate the spent biosensor using an acid-ethylene glycol treatment. The biosensor performed several assays retaining more than 80% of its activity. The sensor had a detection range that is comparable with other rapid techniques. But its use does not require an enrichment step. On another front, the research team has developed a reusable piezoelectric crystal biosensor for determining toxic amines in seafood. In developing the biosensor, they used the enzymes diamine di·am·ine n. Any of various chemical compounds containing two amino groups, especially hydrazine. Noun 1. diamine - any organic compound containing two amino groups oxidase, monoamine oxidase and plasma amine oxidase as the specific biological recognition compounds in a continuous flow system. The specificity and selectivity provided by these enzymes were used along with the amplifying capacity of a quartz crystal transducer. Researchers placed the piezoelectric quartz crystal in an improved electrical oscillator oscillator Mechanical or electronic device that produces a back-and-forth periodic motion. A pendulum is a simple mechanical oscillator that swings with a constant amplitude, requiring the addition of energy at each swing only to compensate for the energy lost because of air circuit and monitored changes in the vibrational resonant frequency. The sensor has shown sensitivity to what are considered FDA FDA abbr. Food and Drug Administration FDA, n.pr See Food and Drug Administration. FDA, n.pr the abbreviation for the Food and Drug Administration. action levels. The system appears more sensitive to diamines than histamine. Further information. A. Garth Rand; phone: 401-874-4081; fax: 401-874-2994; email: enzyme@uriacc.uri.edu. |
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