Non-enzymatic optical sensor for penicillins.
We report on the first penicillin-sensitive fluorosensor not based on the use of an enzyme. Rather, the recognition process relies on the use of an anion carrier (which carries the penicillin anion from the aqueous sample into the membrane), a proton receptor (lipophilic nile blue which accepts the proton, thereby undergoing a change in fluorescence intensity), and a new lipophilic hydroxylic plasticizer material (which facilitates ion transport). All materials are contained in a dyed poly(vinyl chloride) membrane whose fluorescence is monitored. The optical sensor fully reversibly responds to penicillin V over the 0.01-10mM concentration range, and to penicillin G from 0.03 to 10mM. Potential interferences by about 20 other anions have been investigated. Nitrate, salicylate, and ascorbate were found to interfere significantly. These species are, however, usually not present in penicillin bioreactors or drug formulations where penicillin sensing is most important. The sensor does not respond to penicillins containing an aliphatic amino group (such as amoxicillin). The method has been applied for determination of penicillin G in pharmaceutical formulations.
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Institute of Organic Chemistry, Karl-Franzens University, A-8010 Graz, Austria.
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Uray
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Wolfbeis
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