Flexible polyaniline@carbon nanofiber membrane pH electrode for health care

[Display omitted] •A low-cost flexible PANI@CNM electrode was fabricated by chemical in situ polymerization of aniline on the flexible CNM for pH detection.•The PANI@CNM electrode exhibited a high sensitivity of 76.2 mV/pH.•The PANI@CNM electrode maintained a stable sensing performance under mechanical deformation in the temperature range of 25-40℃ for long time use.•The PANI@CNM electrode presented excellent biocompatibility for biomedical application. A low-cost flexible polyaniline@carbon nanofiber membrane (PANI@CNM) electrode was fabricated by chemical in situ polymerization of aniline monomer for pH detection. The preparation condition, morphology, chemical structure and the electrochemical properties of the PANI@CNM electrode were investigated. The result showed that PANI@CNM electrode with high sensitivity of 76.2 mV/pH was prepared with 0.3 M aniline solution and hydrochloric acid as the doping acid at 0℃ for 6 h. FTIR and Raman analysis suggested that the pH sensibility of PANI is attributed to the super-Nernstian behavior of the PANI in the emerald imine form. The PANI@CNM working electrode performs a stable electrochemical property without interference by the common metal iron and biochemical, and has an outstanding reversible pH response in the pH range of 6.32–8.34 without interference of deformation. It also maintained a stable sensing performance in the temperature range of 25-40℃ for long time use and presented excellent biocompatibility. Generally, the PANI@CNM working electrode exhibits great potential in flexible biomedical and wearable pH detection application.