Editing Fingerprint (section)

== Detection of drug use ==
The secretions, skin oils and dead cells in a human fingerprint contain residues of various chemicals and their [[metabolite]]s present in the body. These can be detected and used for forensic purposes. For example, the fingerprints of [[tobacco smoking|tobacco smokers]] contain traces of [[cotinine]], a [[nicotine]] metabolite; they also contain traces of nicotine itself. Caution should be used, as its presence may be caused by mere contact of the finger with a tobacco product. By treating the fingerprint with gold [[nanoparticle]]s with attached [[cotinine]] [[antibody|antibodies]], and then subsequently with a fluorescent agent attached to cotinine antibodies, the fingerprint of a smoker becomes fluorescent; non-smokers' fingerprints stay dark.{{citation needed|date=June 2019}} The same approach, as of 2010, is being tested for use in identifying heavy [[coffee]] drinkers, [[cannabis smoking|cannabis smokers]], and users of various other drugs.<ref>Paul Marks (May 18, 2007) [https://www.newscientist.com/article/dn11887-new-fingerprint-analysis-identifies-smokers.html "New fingerprint analysis identifies smokers"] {{webarchive|url=https://web.archive.org/web/20150610205620/http://www.newscientist.com/article/dn11887-new-fingerprint-analysis-identifies-smokers.html |date=June 10, 2015 }}, ''New Scientist'' (on-line version).</ref><ref>Tom Simonite (April 3, 2006) [https://www.newscientist.com/article/dn8938-fingerprints-reveal-clues-to-suspects-habits.html "Fingerprints reveal clues to suspects' habits"] {{webarchive|url=https://web.archive.org/web/20150610200655/http://www.newscientist.com/article/dn8938-fingerprints-reveal-clues-to-suspects-habits.html |date=June 10, 2015 }}, ''New Scientist'' (on-line version).</ref>