We reported the fabrication of an electrochemical sensor for uric acid (UA) monitoring using metal-free electrode based on heteroatoms (S, N, P, and O) doped carbon (HADC) nanoparticles, derived from polyphosphazene, synthesized via precipitation polymerization reaction between hexachlorocyclotriphosphazene (HCCP) and 1,4-dithiane-2,5-diol (DD) under sonication irradiations at 40 °C, following its modification with benzimidazolium-1-acetate ionic liquid (BIL). The developed HADC-BIL electrode showed a highly sensitive and selective response toward UA even in the presence of highly electroactive interferences such as ascorbic acid (AA), dopamine (DA), glucose (Glu), and hydrogen peroxide (H2O2). Our results demonstrated that the as-fabricated HADC-BIL electrode allows us to detect UA over a linear range of 2–1050 μM with a detection limit of 1.27 μM. Further, we were able to monitor the amount of UA level in the blood of a gout patient using the developed HADC-BIL electrode, which ensures the effectiveness of the developed sensor for the sensitive and selective detection of UA from real samples.