In situ synthesis of dye-modified laser induced graphene/Cu3(HHTP)2 composite for glucose detection

The advancement of non-enzymatic glucose sensors is essential for enhancing the cost-effectiveness and continuous monitoring capabilities of glucose detection systems. Employing innovative materials and device structures constitute key strategies to achieve this objective. Herein, an in-situ growth method of laser-induced graphene (LIG) using dye-stained polyimide colloids formed films on various substrates was introduced. The cost-efficient, rapid, and portable glucose sensor was developed based on LIG patterned via direct laser writing (DLW), combining with a layer-by-layer growth method to deposit Cu 3 (HHTP) 2 (HHTP, 2,3,6,7,10,11-hexahydroxytriphenylene) onto the surface of LIG. By utilizing the first-principles density functional theory (DFT) calculations, the results shows that the LIG result in an upward shift of the d-band of Cu 3 (HHTP) 2 , hindering electrons from filling into the anti-bonding orbitals and improving the adsorption ability of the intermediate product on the surface, enhancing electrode catalytic activity. The glucose sensor has achieved a wide detection range (0.01–22 mM), a low detection limit (3 μM) and an excellent sensitivity (5276 μA mM −1 cm −2 ) in the low concentration range. This work provides novel insights into the growth of LIG on various substrates and offers a non-enzymatic sensor capable of accurate glucose measurements, while demonstrating exceptional reliability, stability and precision.