Light-Activated Gas Sensors for Next-Generation Sensing Platforms: Materials Engineering, System-Level Integration, and AI-Assisted Analysis

Light-activated gas sensors have attracted considerable attention as a promising room-temperature alternative to conventional thermally activated chemiresistive sensors for low-power, miniaturized sensing platforms. However, their practical implementation remains challenging because of inefficient light utilization, UV-dependent photoactivation, cross-sensitive responses, and signal variations under real-world environmental conditions. This review summarizes recent advances in light-activated gas sensors from the perspectives of materials engineering, system-level integration, and AI-assisted analysis. Materials engineering strategies, including three-dimensional nanostructure design, functional overlayers, and photosensitizer engineering, are discussed for improving light utilization, selective gas transport, and visible-light activation. Ambient-light-driven and micro-light-emitting diode-integrated sensing platforms are further introduced for low-power, real-time monitoring with wireless signal readout. In addition, AI-assisted approaches based on time-varying light modulation and environmental compensation are discussed for selective gas recognition under practical operating conditions. Collectively, these advances highlight the importance of integrating materials, device engineering, and analytical strategies to develop reliable and low-power light-activated gas-sensing platforms for environmental monitoring, wearable electronics, and mobile sensing applications.