Fast Degradation of Hydrogen Peroxide by Immobilized Catalase to Enable the Use of Biosensors in Extraterrestrial Bodies.

Hydrogen peroxide has been postulated to be present on the surface of Europa and Enceladus. While it could represent a potential source of energy for possible life-forms, H2O2 may also interfere with a number of current detection technologies, including biosensors. To take advantage of the selectivity and portability of these devices, simple and reliable routes to degrade the potential H2O2 present should be developed and implemented to prepare for this possibility. Unfortunately, most of the current approaches for removing H2O2 are slow, may affect the sample, or could interfere with the performance of biosensors. To address these limitations, catalase was immobilized onto silica particles and used as a means to selectively decompose H2O2 prior to the analysis of common biomarkers with a biosensor. For these experiments, glucose, l-leucine, and lactic acid were used as representative examples of biomolecules such as carbohydrates, amino acids, and organic acids, respectively, which could be used as biomarkers on extraterrestrial bodies. While the decomposition reaction between catalase and H2O2 is well known, to our knowledge this is the first instance where catalase has been used in combination with a microfluidic paper-based analytical device (µPAD) to implement selective sample pretreatment.