42. Highly sensitive dissolved oxygen sensor with sustainable anti-fouling, anti-abrasion and self-cleaning superhydrophobic surface

Long-term sensing of dissolved oxygen in aqueous solution always suffers from adherence of algae, barnacles and clams, and formation of biofilm on sensor surface, which strongly influences the diffusion of oxygen into sensor film. Metabolism of these adhered species consumes oxygen and causes bias on sensor readout. Therefore, commercial sensors are equipped with mechanical brushes to constantly clean sensor surface, which significantly complicates sensor design and causes damage on sensor surface. In addition, extra energy storage and mechanical structure are required, which makes optical sensor bulky and limits its service life. We have developed a robust and highly sensitive dissolved oxygen sensor with good mechanical stability and self-cleaning capability. The sensor was fabricated by doping oxygen-sensitive probe PtTFPP into superhydrophobic coating. The micro/nanostructure formed from 3-5 nm silica sol was solidified with silicone resin, which gave the sensor film excellent mechanical stability. The sensor film exhibits anti-fouling, anti-abrasion and self-cleaning properties. There is no need of mechanical brush to clean sensor surface, which greatly simplifies sensor design. Owing to the porous structure, the sensor shows a high quenchability, with I0/I100 of 77. All these features guarantee the sensor could be used in harsh and dirty conditions for long-term monitoring dissolved oxygen concentration.

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