Lab-on-a-Fiber: Building a fiber-optic sensing platform for low-cost and high-performance trace vapor TNT detection

摘要

By depositing an amplifying fluorescent polymer (AFP) directly onto the core side wall of an optical fiber near the fiber tip, a functional fiber-optic sensing platform is created at a scale of a mere 0.8×0.8×1.6 mm3, including the second fiber tip for excitation light delivery. The device integrates several functional optical components, a chemical sensory film and the necessary laboratory procedures on a minute scale. Here the Lab-on-a-Fiber (LOF) platform is conceptually introduced and proven to be a high-performance and low-cost approach to detection of trace vapors of TNT explosives. The low-cost potential is achieved by straightforward system construction and simple procedures for the AFP film deposition. The high performance is achieved by a dramatic increase of fluorescence emission signal collection, virtually complete suppression of excitation stray light and the fast response to the presence of TNT vapor, which is illustrated by 30% of quenching percentage occurring within 10 seconds.