Keluli Tahan Karat SS304L Terubahsuai Permukaan untuk Sensor Elektrokimia Mikrob dalam Pemantauan Semasa Kualiti Air

Microbial Electrochemical Sensor (MES) is classified as a self-powered electrochemical biosensor and utilising biofilm electrode used as a sensor. Conventional techniques such as ion chromatography (IC), highperformance liquid chromatography (HPLC), and chemical oxygen demand (COD) require large, expensive, and non-portable equipment. Therefore, MES has gained significant attention due to its advantages, including low cost, easy operation, and portability. Stainless steel (SS404L) is widely used in various applications but exhibits lower biocompatibility compared to carbon-based materials when used as an anode. This MES is constructed using modified electrodes through techniques such as carbon coating, electrochemical reduction, flame oxidation, and graphene coating. A nutrient medium stock is periodically supplied daily to enrich the electroactive microbes and maintain the biosensor’s performance at a stable level. Samples are collected and analyzed during pollutant testing to determine pH, conductivity, IC, and COD values. These parameter values are correlated with MES signal data to assess each biosensor’s performance in terms of reaction rate. FESEM-EDX and RAMAN analysis indicated an increase in O content from 2.4% to 19.9% for flame oxidation. For carbon and graphene coatings, carbon content increased from 4.1-9.1% to 48.4-78.6%. The carbon coating exhibited an R² value of 0.7023 for tests using 4-nitrophenol. Meanwhile, for potassium nitrate, the graphene coating demonstrated the highest R² value of 0.8785. A higher R² value indicates a stronger correlation and suggests better performance in electrode modification within MES. This highlights the significance of MES results in water quality monitoring, which can be understood and applied more effectively.