Electrochemical Strategies for Urea Quantification in Wastewater and Biological Fluids

This PhD thesis focuses on the development of innovative electrochemical strategies for the quantification of urea in complex matrices, with particular emphasis on wastewater and biological fluids. Urea is a key compound in both biomedical diagnostics and environmental monitoring, but conventional analytical methods are often unsuitable for rapid, on-site analysis. To address these limitations, the research explores electrochemical sensors and biosensors as cost-effective, sensitive, and portable alternatives. Two complementary approaches are developed and compared. The first is a urease-based biocatalytic flow system designed for continuous and real-time monitoring, optimized through experimental design methodologies and validated on real wastewater samples. The second approach involves non-enzymatic sensors based on nanostructured nickel materials, which provide enhanced stability and catalytic performance without the limitations associated with enzymes. Overall, the thesis demonstrates the potential of both enzymatic and non-enzymatic electrochemical platforms for reliable urea detection, highlighting their applicability in environmental, industrial, and clinical contexts, and outlining future perspectives involving miniaturization, microfluidics, and data-driven optimization.