Electrochemical Biosensor Powered by Pre‐concentration: Improved Sensitivity and Selectivity towards Lactate

Abstract

Abstract We report on the flow‐injection (FIA) electrochemical system coupling with ion‐exchange pre‐concentration column. The response of the FIA system is provided by the advanced lactate biosensor based on Prussian Blue as an electrocatalyst. The FIA system powered by pre‐concentration is characterized by improved selectivity avoiding influence of non‐anionic interfering compounds. The attractive performance characteristics of the system with pre‐concentration which are advantageous over conventional FIA combined with a similar biosensor are: (i) the 50 times improved sensitivity (7.0 A cm −2 M −1 ) and (ii) the calibration range shifted by almost two orders of magnitude towards lower analyte concentrations. The developed FIA system was tested for lactate detection in exhaled breath condensate samples collected from pulmonary patients and sportsmen.