Flexible light-addressable electrochemical sensor using one-step synthesized PTEB organic semiconductors

The light-addressable electrochemical sensor (LAES) enables spatially resolved electrochemical measurements without the need for physical interconnects and fixed electrode geometries. However, current LAES constructions predominantly rely on rigid inorganic semiconductors, limiting their compatibility with flexible electronics. Herein, we present a novel LAES platform based on the organic semiconductor poly(1,3,5-triethynylbenzene) (PTEB), synthesized via a mild copper-catalyzed Glaser coupling reaction. The resulting PTEB film exhibits an interconnected porous network morphology and a direct bandgap of 2.15 eV, along with strong photoelectrochemical responsiveness, high pH sensitivity, and microscale imaging resolution. Particularly, PTEB films deposited on conductive polyester substrates retained 95 % of their photocurrent response under mechanical bending, underscoring excellent mechanical stability. This work addresses key limitations of conventional inorganic semiconductor-based LAES and provides a promising material platform for the development of next-generation flexible and wearable LAES devices.