Highly sensitive glucose biosensors based on organic electrochemical transistors using platinum gate electrodes modified with enzyme and nanomaterials

摘要

Organic electrochemical transistors with glucose oxidase-modified Pt gate electrodes are successfully used as highly sensitive glucose sensors. The gate electrodes are modified with nanomaterials (multi-wall carbon nanotubes or Pt nanoparticles) for the first time, which results in a dramatic improvement in the sensitivity of the devices. The detection limit of the device modified with Pt nanoparticles on the gate electrode is about 5 nM, which is three orders of magnitude better than a device without the nanoparticles. The improvement of the device performance can be attributed to the excellent electrocatalytic properties of the nanomaterials and more effective immobilization of enzyme on the gate electrodes. Based on the same principle, many other types of enzyme sensors with high sensitivity and low cost are expected to be realized by modifying the gate electrodes of organic electrochemical transistors with specific enzymes and nanomaterials. Glucose sensors based on organic electrochemical transistors are suitable for disposable applications. The sensitivity of the device is dramatically improved by modifying the Pt gate electrode with glucose oxidase, chitosan, and Pt nanoparticles, or multiwall carbon nanotubes. The glucose sensor shows a detection limit down to 5 nM and relatively high selectivity and stability.