Neutral‐pH Electropolymerization of Aniline on Hierarchically Porous Laser‐Induced Graphene Electrodes for Dual Biosensing

This study investigates the electrochemical polymerization of aniline on hierarchically porous electrodes based on laser‐induced graphene (LIG) in various pH conditions. Neutral pH electropolymerization on LIG platforms is successful contrary to screen‐printed electrodes. It is found that graphene structures in LIG can assist aniline polymerization even under neutral pH. The influence of polymerization conditions, and dopant selection on the electrochemical, morphological, and structural properties of the resulting polyaniline‐coated LIG (PANI‐LIG) electrodes is systematically examined. Distinct fiber‐like PANI morphologies are successfully formed on LIG substrates under both acidic and neutral pH conditions, preferentially localized at the edges of LIG grooves. The obtained fibrous structure, significantly enhanced the electroactive surface area and facilitated efficient charge transfer. The findings highlight the potential of LIG as a superior substrate for fabricating PANI‐enhanced electrochemical platforms. The developed PANI‐LIG electrodes exhibited excellent potentiometric pH sensing across a broad pH range (1.6–13.2), achieving near‐Nernstian sensitivity. Furthermore, the platform is effectively applied for the electrochemical detection of β‐blockers, including propranolol and metoprolol, indicating superior analytical performance compared to unmodified LIG. This dual functionality highlights the potential of PANI‐LIG system as a versatile and robust sensing platform suitable for point‐of‐care (POC) diagnostics and environmental surveillance of pharmaceutical pollutants.