While many methods can detect drug precursors at a very low concentration in a lab, a portable field system is yet to be developed. A recent project focused on creating such an affordable, sensitive and specific sensing system, which can screen over a large number of compounds. The EU-funded project CUSTOM (Drugs and precursor sensing by complementing low cost multiple techniques) developed a portable optical sensing device for chemical compounds. The sensor can detect traces of drug precursors (ephedrine, safrole, acetic anhydride and benzyl methyl ketone) in air. CUSTOM's sensor is modular, including a microfluidic circuit and a pre-concentrator unit to improve the sensitivity of detection. An incorporated microprocessor handles advanced data processing algorithms and a database. All sensor modules and a power supply are managed by a master control board. A touch screen display provides an easy-to-use machine/user interface. The project's device uses two complementary sensing techniques. One is the rapid and highly sensitive spectroscopic technique based on photoacoustic transduction of infrared absorption. The second is a highly selective fluorescence method, enhanced by special organic macromolecules, binding the analytes through specific antibody-antigen interactions. CUSTOM's developed sensor prototype was tested, with a reliability of detection of 98 % and limit of detection below the parts per million range. Successful commercialisation would significantly reduce trafficking of narcotics and counterfeit drugs across borders through detection capabilities in the micrograms per litre range. Law enforcement and customs officials would have a portable, user-friendly device for on-site inspection. Other areas of application include gas analysis, quality control, and safety and security monitoring systems.
Chemical sensor, drug precursors, optical sensing, chemical compounds