A direct enzyme biosensor for rapid determination of ethanol in plasma

A columnar electrode probe was prepared using platinum Pt and silver Ag as the positive and negative pole. The surface of the probe was coated by graphene oxide nanoparticles to construct a novel nano modified columnar electrode. Ethanol oxidase was directly immobilized on the electrode probe to make ethanol direct biosensor for the determination. The results showed that the detection time was 12 s. The direct test conditions including pH 2-11 and a temperature of 15℃-40℃ . The linear range was 0. 01-2 mg / mL and the limit of detection was 10 μg / mL. The enzyme biosensor showed a good stability with the relative standard deviation RSD of 0. 7% . After the first calibration the enzyme electrode activity remained stable within 33 days with the RSD of 1. 1% . The recoveries were 99. 3%-101% . There was no significant difference between the detection results obtained from this method and the gas chromatography. The new method was expected to be used for the online determination based on the benifits like real time rapid and accurate. © 2021, Youke Publishing Co.,Ltd. All rights reserved.