Nitration: A selective electrochemical label for the determination of activated aromatics

The use of nitration as a method of derivatising activated aromatic species such that the resulting nitro functionality can serve as an electroactive label has been examined. The nitration reaction is conducted so as to minimise oxidative degradation of the target analyte. The nature of the resulting assay protocol has been characterised using phenol as a model analyte and the products resulting from the assay procedure and the subsequent electrochemical investigations identified. The applicability of the protocol was evaluated through the determination of tyrosine and the selectivity of the approach assessed through the recovery of the amino acid within a compositionally complex tissue culture medium. Reduction of the nitro functionality is shown to provide a versatile label through which the parent analyte can be reliably quantified with a high degree of selectivity.