Evaluation of mesoporous polyaniline for glucose sensor under different pH electrolyte conditions

Objectives: Nonenzymatic biosensor-based-conductive polymers like polyaniline are highly electrochemically stable, cheap, and easy to synthesize biosensors, which is the main objective of research as well as testing applied in different pH conditions to get optimum sensitivity.

Methods: A nonenzymatic glucose biosensor based on polyaniline was electrochemically deposited on a glassy carbon electrode; the cyclic voltammetry under range applied voltage -0.2 to 1.2 V vs. Ag/AgCl was employed to synthesize the biosensor electrode.

Results: The polyaniline biosensor electrode properties were characterized, and the morphology surface photographic confirmed mesoporous architecture with many accessible pores, while chemical bonding analysis confirmed the synthesis of polyaniline. The initial investigation examined the pH levels of phosphate-buffered saline, including 5, 5.5, 6, and 6.5. The cyclic voltammetry measurement revealed that the pH=5.5 provides excellent sensitivity toward glucose detection. The sensitivity of pH=5.5 is 68.7 μA mM^-1 cm^-2, and the low detection limit is 1 µM.

Conclusions: The findings above indicate that the biosensor could be an excellent candidate for application in electrochemical glucose sensing under pH=5.5 conditions of phosphate-buffered saline.