Branch Enhanced Photoacoustic Sensor for Comprehensive Sevoflurane Monitoring

• DOI: 10.1021/acssensors.4c03063
• Publication Date: 2025-02-10T13:32:56Z
• Authors: Xueshi Zhang; Yufeng Yang; Lixian Liu; Jialiang Sun; Yi Zeng; Zhifu Yang; Xukun Yin; Xiaoming Zhao; Huiting Huan; Xiaopeng Shao; Andreas Mandelis

Comprehensive sevoflurane monitoring (CSM, concentrations from parts per billion to percent) is essential for the therapeutic diagnosis of anesthetized patients and occupational exposure monitoring. Photoacoustic spectroscopy, with its advantages high sensitivity, wide dynamic range, miniaturization, real-time, holds unique potential CSM. A highly sensitive resonator a small volume an optimal choice regarding limited exhaled gas amount. Wavelength modulation not suitable detecting trace broad absorption lines because depth far optimal. Sensitive detection can be achieved using chopper-based amplitude modulation; therefore, relatively low resonance frequency critical. By introduction flexible polyurethane tubes, branched photoacoustic cell (BPAC) was developed compensate contradiction between miniaturized requirement. The BPAC as 1036 Hz at compact capacity only 2.7 mL. Taking advantage replaceable branches, geometry, frequency, sensitivity could optimized. decoupling excitation paths, avoided degradation thermal-acoustic coupling concentrations. results demonstrated that Branch Enhanced Spectroscopy (BEPAS) sensor yielded 1σ limit 1.61 ppb 3 s integration time, corresponding normalized noise equivalent coefficient 2.2 × 10-9 cm-1 WHz-1/2. With 1 cm long path coupling, BEPAS provided range 8% (154 dB). Continuous on-site testing CSM issues performed, which stability reliability this sensor. may open new avenues ultrasensitivity, large-molecule detection.