[17a-A34-1~9] 4.1 Plasmonics and Nanophotonics

11:15 AM - 11:30 AM JST(2:15 AM - 2:30 AM UTC)English Presentation

[17a-A34-7] High-Sensitivity Plasmonic Sensors Probe for Uric Acid Detection using Surface Funtionalized Gold-Graphene Quantum Dotes stacked Nanocomposites

〇AHMAD SHUKRI MUHAMMAD NOOR^1,2, Olabisi Abdullahi Onifade^1,2, Muhammad Hafiz Abu Bakar^1,2, Mohd Adzir Mahdi^1,2 (1.Department of Computer and Communication Systems Engineering, Faculty of Engineering, Universiti Putra Malaysia, 2.Wireless and Photonics Research Centre of Excellence, Faculty of Engineering, Universiti Putra Malaysia)

Keywords:

Plasmonic Sensor,Uric Acid,Gold-Graphene Quantum Dots

This study introduces a surface-functionalized sensor probe incorporating 3-aminopropyltriethoxysilane (APTES) self-assembled monolayers (SAM) on a Kretschmann-configured plasmonic sensor. The probe employs stacked nanocomposites of gold deposited through sputtering and graphene quantum dots (GQD) deposited via spinning, enabling highly sensitive and accurate uric acid (UA) detection within the physiologically relevant concentration range. Comprehensive characterization of the sensor probe was conducted and validated through field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) techniques. Surface functionalization yielded a 60.64% increase in sensitivity for the sensor probe, resulting in values of 0.0221°/(mg/dL) for gold–GQD probe and 0.0355°/(mg/dL) for gold–APTES–GQD probe, accompanied by linear correlation coefficients of 0.8249 and 0.8509, respectively. The highest sensitivity achieved was 0.0706°/(mg/dL), exhibiting a linear correlation coefficient of 0.993 and a low limit of detection (LOD) of 0.2 mg/dL. Furthermore, surface functionalization significantly enhanced binding affinity, as evidenced by Langmuir constants of 14.29 μM^-1 for the gold–GQD probe and 0.0001 μM^-1 for the gold–APTES–GQD, probe representing a remarkable 142,900-fold increase. The functionalized sensor probe demonstrated notable reproducibility and repeatability, with relative standard deviations of 0.166% and 0.013%, respectively, along with exceptional temporal stability of 99.66%. These findings represent a transformative leap in plasmonic UA sensors, delivering a marked enhancement in precision, reliability and substancial increase in sensitivity.