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Cocaine Biosensor
Aaron Rowe writes "The MIT Technology review reports that a lab at UC Santa Barbara has created a biosensor by attaching a special type of DNA called an aptamer to a gold electrode. When cocaine is present, the aptamer tightly hugs a cocaine molecule and leans over so that a metal tag can touch the gold surface. This causes a spike in a plot of current versus voltage when the electrode is attached to a machine called a cyclic voltmeter."
Gold being soft means less force is required to make a good low-resistance electrical contact. So gold is the king of conductors for contact applications. Add to that the fact that it doesn't corrode or oxidize under normal conditions, it beats the two better conductors (at room temperature), silver and copper.
You are thinking of codeine which is a morphine, i.e. opium, derivative.
Currently, the medicinal use of cocaine is limited to topical anesthesia of the upper respiratory tract and eye because the vasoconstrictive properties of cocaine are desirable during procedures.
Ref
Cocaine is a Schedule II controlled substance, it's illegal in ANY quantity with a license. Its uses are confined to a very limited number of surgeries since it's both a local anaesthetic and vasoconstrictor; that's it. It's not prescribed to patients for any reason. Your post would be true about 100 years ago, however.
Researchers can obtain a license from the DEA to acquire (from a company possessing a DEA license to manufacture/distribute, which every major chemical company like Mallinkrodt or Sigma Aldrich has) and possess controlled substances. It's not easy to get, they obsessively track what you purchase and you have to file paperwork accouting for every last bit of it, but many such licenses exist. For more information on obtaining such licenses, see: http://www.deadiversion.usdoj.gov/drugreg/index.ht ml
How they get the coke for testing?
It's simple. Somebody whips out a twenty dollar bill out of their pocket, because ten out of eleven bills have cocaine on them.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
Xanax isn't an antidepressant. It's a member of the benzodiazapine class of drugs (the most common one actually). Benzodiazapines are the "drug of the day" for Anti-anxiety and also for anaesthesia in high doses. It does the same thing as barbiturates (Qualudes) and Codeine/Morphine/Heroine did in their times respectively. Your employee was probably placed on Xanax temporarily as her medical provider put her on a regime of anti-depressants (Prozac, Paxil, or something else). The Xanax is there to serve essentially as a sedative. This is common practice, especially with patients considered a suicide risk by their Doctors (As sedated people generally don't kill themselves) alhough at the same time is something of risk itself, as it is possible to commit suicide through Benzodiazapine overdose, just as it is possible with Barbiturates, or Opiates. But the medical community has weighed this risk, and generally sedates mild suicide risk patients, while those considered at high risk are generally hospitalized.
There are several properties that make gold suitable for these medicinal applications. I'll give a few that I took from chem rev 2005, 105, 1103(*).:
There are alternatives available, e.g. Palladium, Platinum, but gold is so versatile that it will be the mostly used metal for quite some time I would say.
(*) the article is mostly about self-assembled monolayers, so not very general and most of it will not be useful to you, but it contains a very good explanation of the reason why people choose gold in any of these applications.
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