Work

Tunable Optical–Chemical Coupling in PVA/WO 3 Nanocomposite Guided-Mode Resonance Sensors for Flexible VOC Detection

Year: 2026

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Flexible optical gas sensors that combine scalable fabrication with chemically tunable sensing layers remain underdeveloped for volatile organic compound (VOC) monitoring. Here, we report a poly(vinyl alcohol)/tungsten oxide (PVA/WO 3 ) nanocomposite guided-mode resonance (GMR) platform that enables tunable optical–chemical coupling for enhanced VOC vapor sensing. The device is fabricated on a polydimethylsiloxane (PDMS) substrate through a simple mold-casting process, forming a fully polymeric grating–waveguide architecture without requiring complex lithographic fabrication. Systematic composition control reveals that incorporating WO 3 nanoparticles increases the refractive index of the PVA matrix while simultaneously introducing optical loss, thereby establishing a structure–property trade-off that governs resonance performance. An optimal WO 3 loading of 10 wt % preserves distinct resonance characteristics while maximizing sensing sensitivity. Upon VOC exposure, the nanocomposite GMR sensor exhibits significantly enhanced optical responses, including an approximately 8-fold increase in resonance wavelength shift toward n -butanol compared with the pristine PVA-based device. This enhancement originates from coupled optical–chemical interactions, in which VOC adsorption and diffusion within the PVA/WO 3 grating–waveguide layer induce simultaneous changes in the effective refractive index and film thickness. Furthermore, oxygen-rich WO 3 surfaces promote stronger polar interactions and hydrogen bonding with alcohol molecules, thereby enhancing analyte uptake and amplified resonance shifts. This work demonstrates that nanocomposite-enabled optical–chemical coupling provides an effective and generalizable strategy for simultaneously tailoring optical transduction and analyte affinity in flexible photonic sensors, offering a pathway toward low-power, scalable, and application-specific VOC sensing platforms.

Source: ACS Applied Nano Materials

DOI: 10.1021/acsanm.6c01229

Authors: Shu-Han Hsu, Luqman Hakim, Chao-An Jong, Paiboon Sreearunothai, Sakoolkan Boonruang

Institutions: Thammasat University, TCI (Taiwan), National Institutes of Applied Research, National Science and Technology Development Agency, National Electronics and Computer Technology Center

Language: English

Topic: Advanced Fiber Optic Sensors

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: Thailand Science Research and Innovation, Sirindhorn International Institute of Technology, Thammasat University