Detection of Organophosphorus Compounds by Covalently Immobilized Organophosphorus Hydrolase

摘要

As a consequence of organophosphorus (OP) toxins posing a threat to human life globally, organophosphorus hydrolase (OPH) has become the enzyme of choice to detoxify such compounds. Organophosphorus hydrolase was covalently immobilized onto a quartz substrate for utilization in paraoxon detection. The substrate was cleaned and modified prior to chemical attachment. Each modification step was monitored by imaging ellipsometry as the thickness increased with each modification step. Thechemically attached OPH was labeled with a fluorescent dye (7-isothiocyanato- 4-methylcoumarin) for the detection of paraoxon in aqueous solution, ranging from 1 nanomole to 10 micromole. UV- visible spectra were also acquired for the determination of the hydrolysis product of para-oxon, namely p-nitrophenol.