An Affordable Amperometric Gas Sensor Based on Polyvinylidene Fluoride Solid-State Electrolyte for Highly Selective Detection of ppm-Level H<sub>2</sub> at Room Temperature
Yue Zhang, Yangjuan Lin, Zheng Yang, Rong Qian, Dongting Yao, Kun Li, Chuanhui Zhang, Jun Zheng, Chunchang Wang, Youmin Guo
Abstract
Currently, the assessment of irritable bowel syndrome (IBS) through the detection of H 2 levels in exhaled breath using commercial gas sensors remains a challenging task. In this work, we presented a cost-effective amperometric gas sensor capable of monitoring parts per million-level H 2 at room temperature by grafting polystyrene sulfonic acid onto polyvinylidene fluoride (PVDF- g -PSSA), creating a thermal stable and highly adaptable solid polymer electrolyte. This PVDF- g -PSSA exhibited a high tensile stress value of 9.72 MPa and ionic conductivity of 2.73 × 10 –2 S cm –1, which is comparable with that of the Nafion N115 membrane. The amperometric gas sensor based on the PVDF- g -PSSA membrane exhibited preferable sensing performance, including a response current of 174.3 nA to 50 ppm of H 2 at room temperature and 50% relative humidity. Additionally, it also displayed an acceptable response–recovery time of 96 and 54 s, limit of detection (LOD) of 1 ppm H 2, and selectivity for H 2 over other interfering gases. Remarkably, this sensor demonstrated a highly linear relationship (4.6 nA/ppm H 2 ) with a correlation coefficient of 0.9998. Furthermore, we also applied this sensor to distinguish parts per million-level H 2 concentrations in simulated exhaled breath. These findings demonstrated an affordable amperometric H 2 gas sensor for detecting ppm-level H 2 at room temperature, even without requiring a bias, thereby promising for biomarker detection in exhaled breath.