Highly enhanced sensitivity of optical oxygen sensors using microstructured PtTFPP/PDMS-pillar arrays sensing layer

In this work, we presented a facile and cost-effective approach to fabricate novel PtTFPP/PDMS micro-pillar array (MPA) sensor film with I 0 /I 100 for gaseous oxygen and dissolved oxygen are 288 and 84, respectively. The sensitivity of the sensor film exhibited over ∼30-fold increment when compared with contemporary PtTFPP/PDMS-based oxygen sensors. The detection limit was as low as 0.10   μmol/L, which means that the ultrasensitive sensor films enable reliable monitoring of dissolved oxygen (DO) within nanomolar concentration ranges that are particularly difficult to achieve in previous works. Furthermore, the remarkably light intensity-changing characteristic of the sensing film under lower O 2 partial pressures facilitates convenient identification of O 2 concentrations even with the naked eye. We believe that the proposed device could be a promising candidate in various oxygen sensing fields such as nearly anoxic systems, unsteady pressure measurement and unsteady flow visualization, etc.