Science Inventory

FIBER-OPTIC BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS. (R823663)

Citation:

Mulchandani, A., S. Pan, AND W. Chen. FIBER-OPTIC BIOSENSOR FOR DIRECT DETERMINATION OF ORGANOPHOSPHATE NERVE AGENTS. (R823663). BIOTECHNOLOGY PROGRESS. American Chemical Society, Washington, DC, 15:130-134, (1999).

Description:

A fiber-optic enzyme biosensor for the direct measurement of organophosphate nerve
agents was developed. The basic element of this biosensor is organophosphorus hydrolase
immobilized on a nylon membrane and attached to the common end of a bifurcated optical fiber
bundle. The enzyme catalyzes the hydrolysis of organophosphate compounds to form stoichiometric
amounts of chromophoric products that absorb light at specific wavelengths. The back-scattered
radiation of the specific incident radiation was measured using a photomultiplier detector and
correlated to the organophosphate concentration. The effects of buffer pH, temperature, and the units
of enzyme immobilized on the steady-state and kinetic response of the biosensor were investigated to
optimize the operating conditions for the fiber-optic enzyme biosensor. These conditions were then
used to measure parathion, paraoxon, and coumaphos selectively without interference from
carbamates and triazines. Concentrations as low as 2 mu M can be measured in less than 2 min using
the kinetic response. When stored in buffer at 4 degrees C the biosensor shows long-term stability.
(26 References)

Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Product Published Date: 01/01/1999
Record Last Revised: 12/22/2005
Record ID: 66786

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL CENTER FOR ENVIRONMENTAL RESEARCH