Zhouyu Chen, Leyi Tang, Jiancheng Zhou, Ruijuan Wen, Jianfei Ma, Chi Zhang, Helan Zhang, Zhi-Hao Zhao, Yanyan Luo*, Yu Fang*. Sens. Actuators B Chem. 2026, DOI: 10.1016/j.snb.2025.138996

BTEX (benzene, toluene, ethylbenzene, and xylenes) are common volatile pollutants in the environment that pose significant health risks due to their acute toxicity. Long-term exposure to these compounds can lead to severe health issues, including leukemia and neurological disorders. Therefore, there is an urgent need to develop highly sensitive on-site real-time monitoring technologies. However, existing detection methods often struggle to balance sensitivity at the parts per billion (ppb) level, rapid response time, and long-term stability.

Figure 1. Film device optimization.

Figure 2. Sensing performance of the BTEX sensor.

In this study, we used a highly fluorescent perylene bisimide derivative (P-PBI) as our sensing material. By systematically optimizing the thin-film device structure and optical unit, we successfully addressed several key technical challenges, including the uniformity of the sensing film, mass transfer efficiency, and signal-to-noise ratio. As a result, we developed a high-performance thin-film fluorescent sensor. This sensor exhibits ultra-high sensitivity for BTEX components, achieving a detection limit of 8.6 ppb for benzene and 1.2 ppb for o-xylene. It has a response time of under 4 seconds and a recovery time of within 10 seconds. The sensor demonstrated excellent performance over an eight-month stability test and sustained 1000 fatigue cycles, outperforming traditional gas chromatography-flame ionization detectors (GC-FID) and portable photoionization detectors (PID). Successful validation of the sensor in real-world scenarios, such as gas stations and adhesive workshops, further confirms its exceptional reliability in complex environments, providing an effective solution for rapid on-site BTEX monitoring.

First Author: Chen Zhouyu, master’s student, Shaanxi Normal University

Correspondence Authors: Prof. Fang Yu, R&D Engineer Luo Yanyan, Shaanxi Normal University

Full Text Link: https://www.sciencedirect.com/science/article/pii/S0925400525017721