One-Pot electrochemical fabrication of high performance amperometric enzymatic biosensors using polypyrrole and polydopamine

We report a novel strategy to offer a high-performance biosensor platform by fabricating an electrically conductive and adhesive electrode composed of polypyrrole (PPy)/polydopamine (PDA) with enzymes (i.e., glucose oxidase (GOx) or lactate oxidase (LOx)) by one-step electrochemical coating. We focused on electrochemical glucose sensing using PDA/PPy and GOx as a model biosensor. PDA/PPy/GOx biosensor was highly sensitive (28 times higher) compared to the PPy/GOx, which appeared to result from enhanced GOx immobilization and efficient signal transduction by PDA/PPy. A selective layer of polyphenol (PPh) on the PDA/PPy/GOx successfully eliminated possible interference. Finally, the GOx biosensor displayed a good sensitivity of 22.15 mu A mM(-1)cm(-2), a short response time of 5-6 s, a linear range up to 5.0 mM, and a detection limit of 138 mu M glucose (R-2 = 0.995). Human blood serum tests accurately measured glucose concentration. PPh-layered PDA/PPy/GOx biosensor maintained exceptional stability over 90 days (93.9%). Furthermore, we fabricated a lactate biosensor (PDA/PPy/LOx) by electrochemical PDA/PPy deposition with LOx and demonstrated the significant improvement of a lactate sensing ability compared to PPy/LOx. This facile fabrication strategy involving PDA/PPy and enzymes will serve as an attractive platform for highly sensitive and stable biosensors, such as urate and bilirubin detection. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.