In situ and rechargeable generation of silver nanoparticles on polymeric membrane ion-selective electrodes for marine biofouling mitigation

Biofouling is a great challenge for polymeric membrane ion-selective electrodes applied in environmental monitoring. Herein, we propose a simple and universal approach to immobilize silver nanoparticles (Ag NPs) on ISEs for biofouling mitigation. As a proof-of-concept, a PVC-based carbonate-selective electrode is chosen as a model sensor. Ag NPs can be readily formed on the surface of electrode membrane by immersion of the electrode into an AgNO 3 solution, followed by immersion in a NaBH 4 solution. Experimental results show that the Ag NPs modification does not impair the electrode’s analytical performance (i.e., selectivity, sensitivity, response time, and detection limit), but provides the electrode with excellent antibacterial properties and improved analytical stability when exposed to a high concentration marine bacterial suspension of 10 8 CFU mL −1 . The Ag NPs show a low release rate and excellent rechargability on the electrode, thus ensuring sustainable biofouling resistance. Moreover, the proposed method demonstrates good applicability to other electrodes based on polymeric membranes, such as chloride-selective electrode and lead-selective electrode.