How can we use actually test for the presence of these opiates?

 

(from Peter-John Holt et al., Bioluminescent Assay for Heroin and Its Metabolites, Anal. Chem. 1996, 68, 1878.)

 

 When heroin is added to an enzyme solution containing appropriate proportions of heroin esterase, morphine dehydrogenase, luciferase and NADP+ (refer to diagram above), the heroin molecule is broken down into the products shown, and light will be emitted (see bottom right of diagram). By monitoring the amount of light produced, a quantitative description of the amount of heroin in the sample can be determined. It is through this procedure that more sensitive tests have been devised for measuring heroin and morphine contents in fluids.

 

If it is desired to test for morphine without heroin, an enzymatic assay would be created, but without heroin esterase, to degrade the morphine molecules into simpler structures and produce light.

 

This same procedure can be extended to immobilized enzyme assays. An enzyme solution is made up of NADP+, morphine dehydrogenase, sigma luciferase and FMN in a potassium phosphate buffer (see below). Square sections of crystal polystyrene are immersed in this solution and put on ice for one hour. The membrane squares are then moved to the edge of the dish and allowed to dry. Each square is then placed at one end of a polystyrene strip, at which time a small amount of decanal should be applied to the surface of each membrane square. This procedure bonds the membrane to the polystyrene substrate within seconds, and will evaporate to dryness in a few minutes. For the heroin test, 200 microliters of heroin esterase solution (50 units/mL) was included in the enzyme solution.

 

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