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, more notably, integrated EBC collector and analyser do not exist. Under current suggested protocol EBC samples for hydrogen peroxide analysis needs freezing at -70 C immediately after collection but still exhibit instabilities in concentration. To address those difficulties and to provide easy-to-use devices for patients, we have proposed a portable integrated EBC analyser, which gives measurement results within 3 minutes. The device incorporates Peltier cooling for sample collection; electronics control system and a disposable chemically modified amperometric sensor. Cooling system and device architecture were designed based on thermofluidic analysis of Falkner-Skan solution. Theoretical modelling and experimental evidence suggest that previously reported large variations between analyte concentrations arise from poor control of the condensation process. Fundamental studies suggest higher condensation temperature favours more concentrated analyte collection, relieving the burden on electrochemical sensor limit of detection (LOD). Low hydrogen peroxide in EBC presents another challenge. We have developed a modified Prussian blue (PB) sensor, by blending PB in conducting polymer matrix to increase PB density on electrode as well as cross linking matrix to improve the mechanical properties and enhance processability. Full mechanistic investigation using rotation disk electrode and chronoamperometry experiments reveal the kinetics of the sensor and informed subsequent development. The sensor has been demonstrated to measure hydrogen peroxide in EBC.