Selfi, Dewi Anggraeni, Dionysius J D H Santjojo, Wildan Panji Tresna, Sulaiman Wadi Harun, Masruroh
High sensitivity is crucial for fiber-optic surface plasmon resonance biosensors. This study presents an enhanced Au-coated SPR sensor functionalized with a TiO₂/Carbon Quantum Dots (CQDs) nanocomposite thin film. The CQDs were sustainably synthesized from sugarcane bagasse using an eco-friendly hydrothermal method. By employing Ultrasonic Spray Pyrolysis, the TiO₂/CQDs nanocomposite optimizes both the plasmonic layer and the evanescent-field distribution. Sensor performance for the human IL-17 isolate showed significant improvements: sensitivity increased significantly from 2947.49 nm/RIU (single Au) to 4244.38 nm/RIU Au–TiO₂/CQDs, achieving a Figure of Merit (FOM) of 38.75 RIU⁻¹. This environmentally friendly approach promises highly sensitive SPR sensor development. © 2026 The Author(s).
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Brawijaya, Malang, 65145, Indonesia; Research Center for Photonics, Nanotechnology and Materials Research Organization, National Research and Innovation Agency (BRIN), South Tangerang, Indonesia; Department of Electrical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, 50603, Malaysia; Research Center for Advanced System and Material Technology, Universitas Brawijaya, Jl Veteran 12-16, Malang, 65145, Indonesia
