Aerosolized Fentanyl Electrochemical Nano-Sensor for Field Detection

The intentional or accidental aerosolization of chemical and biological agents, such as fentanyl, fentanyl analogs, and other opioids, represents a growing and asymmetric threat to US military operations and homeland security. In operational settings, these threats compromise force readiness and border protection, especially for warfighters or first responders who encounter unknown airborne substances. Current detection technologies face serious limitations. For example, benchtop laboratory tools like GC-MS offer high sensitivity and selectivity but are impractical in field operations and time-sensitive environments. On the other hand, portables methods (e.g., colorimetric strips and ELISA) are susceptible to environmental interference. They often require 3-10 minutes to produce positive results, which could prove fetal when dealing with ultra-potent agents like fentanyl. In addition, most research has focused on gas or liquid-phase samples containing fentanyl or its metabolites. The study of aerosolized fentanyl requires significantly more attention. Therefore, there is a pressing need for an electrochemical sensing platform that detects aerosolized fentanyl in a real-time, ultrasensitive, selective, and affordable manner. Such a platform must also address operational constraints including shelf life and reusability for field applications. Recent advances in single-walled carbon nanotube (SWCNT)-based field-effect transistors (FETs) offer a promising foundation to meet this pressing need. Prior studies have shown femtomolar sensitivity for norfentanyl and fentanyl by functionalizing SWCNTs with corresponding antibodies. However, adaptation for aerosolized fentanyl detection remains unexplored. To address this, we propose leveraging these sensor technologies in a novel configuration customized for aerosol applications. Our proposed solution integrates a fentanyl antibody-functionalized, gold nanoparticle (AuNP)-decorated SWCNT FET device with a compact aerosol-to-liquid collection module. The complex sensor platform directly captures aerosolized fentanyl into a buffered solution, followed by FET measurements. Data from these specific SWCNT-base FET sensors will be coupled with AI/ML algorithms for signal discrimination. Additionally, this low-SWaP and low-cost sensor can be handheld or integrated into drones, aimed for dual-use in law enforcement and public health. Last, our sensing technology can be easily adapted to other opioids and drugs by customizing the antibody functionalization and nanoparticle decoration. The core Phase I goal is to develop a electrochemical sensor system that detects airborne fentanyl in liquid aerosols with (1) rapid response time, (2) high sensitivity, (3) high selectivity and accuracy (against structurally similar opioids), and (4) great reproducibility. Full system miniaturization and mobile integration are anticipated in a subsequent development phase.