Flexible and Highly Sensitive Nitrite Sensor Enabled by Interconnected 3D Porous Polyaniline/ Carbon Nanotubes Conductive Hydrogels
Conducting polymer hydrogels with superior electrical responsiveness, adjustable chemical property, and high electrical conductivity are highly desired for electrode materials in assembling flexible and wearable sensors. Herein we have synthesized PANI-CNTs composite hydrogels through self-assembly strategy for nitrite detection. High-density CNTs are tightly absorbed into PANI hydrogels’ 3D porous hierarchical microstructure through π-π interaction to form PANI-CNTs hydrogels. PANI hydrogels’ 3D porous network and CNTs’ high conductivity largely benefits for electrolyte ions’ diffusion and transfer. PANI-CNTs hydrogels’ hydrophilic nature provides outstanding interface between electrolyte and electrode. The PANI-CNTs hydrogels modified electrode shows high sensitivity (271.48 μA•mM-1•cm-2), with an average response time of 3 s, a linear range from 20 μM to 1.8 mM, and a low detection limit of 7.8 μM. Moreover, a flexible electrochemical sensor for nitrite detection was successfully prepared by coating PANI-CNTs hydrogels onto printed electrode plate, exhibiting good sensitivity of (254.54 μA•mM-1•cm-2). This PANI-CNTs hydrogels present giant potential in designing flexible and wearable sensors, in which the composite hydrogels can be applied as sensor part and electrolyte storage part simultaneously.
- This article is part of the themed collection: Bioanalytical sensors for real world applications