Highly sensitive and stable zwitterionic poly(sulfobetaine-3,4-ethylenedioxythiophene) (PSBEDOT) glucose biosensor

Abstract

A zwitterionic poly(sulfobetaine-3,4-ethylenedioxythiophene) (PSBEDOT)-based glucose biosensor was fabricated via encapsulating glucose oxidase (GOx) in a one-step electropolymerization method. Integrating conductivity and hydrophilic properties, PSBEDOT provides a great framework for GOx immobilization and stabilization. The anti-fouling, high-sensitivity, and long-term stability properties of PSBEDOT-GOx make it a promising platform for long-term and continuous glucose monitoring.

Scheme 1. Zwitterionic poly(sulfobetaine-3,4-ethylenedioxythiophene) (PSBEDOT) glucose biosensor.

Fig. 1. eQCM frequency shift of fibrinogen (a) and human blood plasma adsorption (b) on the PSBEDOT–GOx (red) and PEDOT–GOx (black) surfaces.

Fig. 2. Amperometric response of the PSBEDOT–GOx (red) and PEDOT–GOx (black) biosensors to the successive addition of glucose in PBS; the concentration of glucose was increased from 0.1 mM to 50 mM.

Fig. 3. Corresponding calibration plot showing amperometric response vs. glucose concentration: (a) 0.1 mM to 0.5 mM; (b) 1 mM to 20 mM. Replicates = 3.

Fig. 4. Response of PSBEDOT–GOx (a) and PEDOT–GOx (b) sensors to glucose from 0.1 mM to 50 mM after long-term storage under dry conditions. The response of PSBEDOT–GOx (c) and PEDOT–GOx (d) sensors to glucose from 0.1 mM to 50 mM after long-term storage under wet conditions. Current response of PSBEDOT–GOx (e) and PEDOT–GOx (f) glucose sensors incubated in 100% human blood plasma at 0, 7, 14, 21, 28 and 35 days until the current signal was lost completely as a function of glucose concentration (0.1–50 mM). Replicates = 3.