Table 2 The comparison of pH sensing sensitivity among different flexible pH sensors in the literature.

Our sample

− 74.45

2–12

This work

Flexible PANI membrane

− 58.57

5.45–8.62

³⁸

Flexible IrO_x/AgCl electrode

− 51.7

1.5–12.1

²⁸

Polyaniline nanopillar sensor

− 60.3

2.09–12.0

³⁹

Flexible graphene pH sensor

− 62

5–8

⁴⁰

Au composite strip-based sensor

− 57

3–8

⁴¹