Diatom frustules based dissolved oxygen sensor with superhydrophobic surface

Dissolved oxygen (DO) sensors for the practical application usually require good resistance to complex and extreme environments, such as acidic or alkaline corrosion, seawater sediment erosion, protein or bacteria adhesion, etc. Diatom frustules (DFs) are protective shell structures extracted from diatoms, which have delicate hierarchical pores and a large specific surface area, showing their utilization potential as oxygen sensing materials. Herein, we developed a superhydrophobic DO sensor which use the DFs as matrix materials. The sensor was fabricated by spraying the mixture of 1 H,1 H,2 H,2 H-perfluorooctyltriethoxysilane (PFOTS) modified DFs and oxygen-sensitive probe platinum (II)− 5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorophenyl)-porphyrin (PtTFPP) on the bonding substrate. In the DO sensor, DFs provides a tough micro/nano surface structures and PFOTS offers low surface energy, both of which led to a robust superhydrophobic surface of the sensor. Because of the porous structure of DFs and the diffusion enhancement effect of fluorine on oxygen, the sensor has high DO sensitivity, I/I which represents for oxygen sensitivity reaches up to 129. Additionally, the sensor showed good tolerance on mechanical abrasion, acidic or alkaline corrosion and biofouling. Owing to these good performances, the use of DFs is expected to provide a new strategy for the rational design of high performance DO sensing devices.