High-performance amperometric biosensor for flow injection analysis consisting of a replaceable lactate oxidase-based mini-reactor and a silver amalgam screen-printed electrode

•Electrochemical biosensor for L-lactic acid determination in flow injection analysis.•Biosensor is based on the spatially separated biorecognition and detection parts.•Monitoring of oxygen consumption at silver amalgam screen-printed electrode.•Covalent immobilization of lactate oxidase at a mesoporous silica powder.•No significant changes in the biosensor response were observed after 350 measurements.