Modified urease-based protocol for trace urea quantification in photoelectrochemical/electrocatalytic C-N coupling systems.

Photoelectrochemical/electrocatalytic urea synthesis through C-N coupling between CO2 and nitrate represents a transformative strategy for sustainable nitrogen fixation. However, current research is hindered by the lack of reliable quantification protocols that can operate in complex electrolytic environments, where pervasive chemical interference and dynamic system instability induce profound inaccuracies in conventional methodologies. Metrological failures caused by nitrite-induced chromophore degradation in colorimetric assays and pH-dependent enzyme suppression distort catalyst evaluation. This has hindered the integration of advanced catalytic materials sensitive to electrolyte composition, limiting mechanistic studies and material innovation. To address this fundamental challenge, we engineered a universally applicable urease-based protocol that integrates pH-stabilized phosphate buffer and nitrite background calibration to establish an interference-resistant quantification cascade that ensures sustained enzymatic fidelity under electrolytic extremes. This optimized workflow delivers robust trace-urea detection with minimized error, enabling trustworthy catalyst benchmarking and accelerating the translation of electrocatalytic urea synthesis from fundamental discovery to scalable implementation.