High responsivity, ultra-flexible, self-driven solar-blind fibrous photoelectrochemical detector for seawater antibiotic detection

The detection of antibiotics in seawater is essential for ensuring the safety and sustainability of the marine environment. However, existing detection methods are hindered by limitations such as slow response times, complex operations, or high costs. In this study, we propose the omnidirectional growth of high-quality α-Ga₂O₃ nanopillar arrays on a flexible carbon nanotube fiber (CNTF) substrate to construct a self-powered fibrous photoelectrochemical sensor for antibiotic detection. Importantly, the device effectively mitigates signal interference from ambient light and seawater fluctuations due to its ultra-flexibility and solar-blind photoresponse characteristics. Specifically, a significant photoresponsivity of 61.6 mA/W, a detectivity of 3.03 × 10¹¹ Jones, and an external quantum efficiency of 30.1 % are obtained, which are surpassing the performance of most fibrous photodetectors. Moreover, the device with 360° omnidirectional detection capability exhibits no significant degradation of photoresponse during 2000 bending cycles or long-term continuous operation. Notably, under combined effects of enhancing the separation efficiency of photogenerated carriers by organic ions and competing for solar-blind UV light absorption between antibiotic molecules and Ga₂O₃, the α-Ga₂O₃@CNTF detector demonstrates the capability to detect sulfonamides, quinolones, and tetracyclines at various concentrations in seawater. This work provides valuable insights into developing high-performance, cost-effective, and user-friendly devices for advanced seawater antibiotic detection technology.