Metal-organic framework-derived porous Cu2O/Cu@C core-shell nanowires and their application in uric acid biosensor

Uric acid (UA) is an important indicator for human metabolism, therefore it is of great significance to develop a sensitive and selective biosensor for monitoring UA and diagnosing relevant disorders. In this paper, porous Cu2O/Cu@C core-shell nanowires (NWs) are synthesized by thermal decomposition of HKUST-1 NWs. Subsequently the nanowires are used as electrode materials to fabricate UA biosensors. By controlling the conditions of calcination, we obtain composite particles consisting of cuprous oxide and copper nanoparticles which are wrapped within the nanowire shell formed by non-graphitic carbon material. These nanowires exhibit excellent electrocatalytic capability at low working potential that is beneficial for improving the anti-interference ability of UA biosensors. Furthermore, carbon and copper in the substrate accelerate electron transfer to substantially improve the sensitivity of the UA biosensors. Sensitivity of 330.5 mu A.mM(-1).cm(-2) and a linearity range from 0.05 to 1.15 mM (R-2 = 0.997) at a working potential of -0.5 V vs SCE are achieved. We also demonstrate the practicality of our biosensors for clinical applications by measuring the concentration of UA in diluted human urine.