Abstract: The invention relates to an optical resonator biosensor for the detection of butyrylcholinesterase comprising two optical resonator biosensor systems in which in the first optical resonator biosensor system a probe is attached to the resonator wherein said probe is able to bind butyrylcholinesterase. Preferably said probe is able to bind uninhibited butyrylcholinesterase. In the second optical resonator biosensor system preferably an antibody is attached to the resonator, wherein said antibody is able to bind butyrylcholinesterase, preferably wherein said antibody is able to bind both inhibited and uninhibited butyrylcholinesterase.

Abstract: The invention concerns derivatives of drosocin which have an increased half-life in mammalian serum by substituting one or more of the amino acid residues of wild type drosocin with another amino acid or a peptidomimetic moiety capable of replacing said amino acid. These derivatives can be used for antibiotic therapy or in a bacteriocidal composition.