An amperometric lactate biosensor using H2O2 reduction via a Prussian Blue impregnated poly(ethyleneimine) surface on screen printed carbon electrodes to detect anastomotic leak and sepsis

Lactate detection by biosensors is of increasing importance in clinical applications to provide rapid, point of care, serial measurements for early diagnosis of disorders such as intra-abdominal sepsis to reduce morbidity and mortality. We present a method for the detection and quantification of lactate using pre-impregnated Prussian Blue screen printed carbon electrodes and polyethyleneimine polymer. The resulting amperometric lactate biosensor exhibited a reproducible response to lactate. Data was validated using cyclic voltammetry, and key parameters for sensor fabrication were systematically evaluated. The biosensor showed little response to possible interferents, including ascorbic acid. Biosensor results using clinical peritoneal drain fluid samples demonstrated significant concordance with a commercial lactate assay (rs = 0.891, P = 0.001). We therefore present a robust and sensitive lactate biosensor using a simple adsorption based methodology which has the capacity to be a potentially valuable diagnostic test for intra-abdominal sepsis and anastomotic leak.