Development of CP/Fe-MOF electrochemical sensor for sensitive detection of uric acid in biological fluids

Uric acid (UA) concentrations serve as pivotal health indicators. This study developed a novel carbon paper (CP) and Fe-MOF composite and utilized it as an efficient electrochemical sensor for the detection of UA. SEM, XRD and FT-IR confirms the successful in-situ growth of Fe-MOF on the carbon paper substrate. The sensor exhibits a linear response to UA concentrations ranging from 3 to 400 μM, with a high correlation coefficient (R 2  = 0.998) and a LOD of 2.798 μM. The sensor demonstrates excellent reproducibility, with an RSD of less than 5%, and notable long-term stability, retaining 96.4% of its initial current response after one month. Furthermore, it exhibits selectivity in UA detection even in the presence of interfering species such as ascorbic acid and dopamine. The feasibility of using the CP/Fe-MOF sensor to detect UA in a typical biological fluid, bovine serum, was also evaluated by the standard addition method. The enhanced sensing performance can be attributed to the preservation of the carbon paper's superior electron transport properties within the composite material, combined with the increased specific active sites by the Fe-MOF components, which significantly boost the electrochemical sensing capabilities.