Mucin/carbopol matrix to immobilize oxalate oxidase in a urine oxalate amperometric biosensor

The use of a sulphonated membrane as internal membrane allowed rejection of the most important electrooxidable urine interferents. The recovery assays were highly satisfactory. The wide linear response in the range 2-400 μM after 1/10 urine dilution (corresponding to 20-4000 μM) made it suitable for clinical range. High correlation with the standard spectrophotometric method was obtained (r2 = 0.98, y = 0.89x, n = 25).