Analyst (2020).
Exhaled breath condensate (EBC) based breath analysis has gained significant interest in pulmonary disease diagnostics over the past few years due to the non-invasiveness and simplicity of the technique. Most approaches to date have separated EBC collection from the subsequent lab-based analysis. Here we report a low-cost disposable hydrogen peroxide (H2O2)sensor modified with a new composite consisting Prussian Blue (PB), PEDOT:PSS, and crosslinker ethylene glycol (EG) and divinyl sulfone (DVS) combined with a thermoelectric EBC collection device. Theoretical modelling suggests that previously reported large variations between analyte concentrations arise from poor control of the condensation process. Experimental data confirm the model predictions and proof-of-principle human samples were analysed showing good agreement with fluorometric methods.)