Dual-Channel Microfluidic Photoionization Detector

Microfluidic photoionization detectors (μPIDs) have long served as a highly sensitive gas sensor in a microgas chromatography (μGC) device. However, their high electrical impedance renders them susceptible to various noise sources, often hindering their performance and bandwidth. Here, we developed a silicon-based, microfluidic differential dual-channel photoionization detector (μDPID) to reject common-mode noises and enhance operational reliability under varying environmental conditions. Comprehensive analyses of the μDPID were conducted by benchmarking its performance against the corresponding μPID configuration for different noise sources. Experimental results demonstrate that the μDPID significantly enhances noise immunity, providing a linear dynamic range of ∼2 × 10⁵ (from 38.5 nA to 0.21 pA) at a large bandwidth of 106 Hz. These advancements underscore the μDPID's potential for developing high-performance μGC systems such as portable ultrafast GC and comprehensive 2-dimensional GC for rapid, in situ trace vapor detection.