Sea-urchin-like cobalt-MOF on electrospun carbon nanofiber mat as a self-supporting electrode for sensing of xanthine and uric acid

The early detection of abnormal levels of purine derivatives such as xanthine (XA) and uric acid (UA) in thebodyfluid could be helpful to prevent various diseases. A novel free-standing biosensor electrode was fabri-cated by solvothermal deposition of sea-urchin-like cobalt(benzene 1,3,5-tricarboxylic acid)MOF (Co(TMA)MOF) on the surface of electrospun porous carbon nanofibers (CNFs) and explored for the electrochemicaldetection of XA and UA in the alkaline medium (pH similar to 13). The morphological and textural features of theas-fabricated Co(TMA)MOF@CNF hybrid mat were evaluated. The electrochemical investigation of the Co(TMA)MOF@CNF electrode demonstrated an excellent electrocatalytic response toward the selective detectionof XA and UA. The diffusion-controlled electrooxidation reactions of XA and UA were identified. The calibra-tion plots of amperometric current response vs analyte concentration were found linear over a broad concen-tration range 25-700 mu M, along with low detection limits (LOD, S/N = 3) of 96.2 nM and 103.5 nM for the XAand UA, respectively. The sensor sensitivity is calculated to be 14.28 mu A mu M-1cm-2for XA and 5.78 mu A mu M-1cm-2for UA. The present hybrid sensor was investigated to monitor XA and UA in blood serum and urine ofgout patients, and the results were satisfactory with recovery values around 99 %.

Automated summary

A novel free-standing biosensor electrode was fabricated for the selective detection of xanthine and uric acid in body fluids. The electrode showed low detection limits, good sensitivity, and satisfactory performance in monitoring xanthine and uric acid in blood serum and urine.