Chemically Treated Polyimide Film Modified by Liquid Phase Epitaxially Grown HKUST-1 MOFs for Electrochemical Sensing Applications

The development of flexible and high-performance electrochemical sensors is essential for applications in fields such as environmental monitoring, healthcare, and wearable electronics. Conventional electrode materials often face limitations in flexibility, surface area, and conductivity, making it necessary to explore innovative materials and fabrication techniques. In this work, we present a novel strategy to enhance EC sensor performance by combining the layer-by-layer growth of HKUST-1 metal-organic frameworks (MOFs) with laserinduced graphene (LIG) on a flexible Kapton substrate. The LBL method was employed to grow uniform HKUST-1 MOF films on chemically treated Kapton, followed by the LIG process to convert the MOFs into a conductive graphene structure, with uniformly distributed metal oxide nanoparticles. This approach resulted in flexible electrodes with increased surface area and improved charge transfer properties. Cyclic voltammetry measurements demonstrated a significant enhancement in the electrochemical performance of the HKUST-1 modified Kapton electrodes compared to untreated Kapton, particularly in the higher voltage range. The results indicate that this hybrid fabrication method effectively addresses the challenges of electrode flexibility and conductivity while improving sensor sensitivity. The integration of MOFs with LIG provides a scalable and efficient approach for creating advanced flexible electrodes that hold great potential for the development of nextgeneration EC sensors.