Luminescence-based detection and identification of illicit drugs

Abstract

This perspective describes current state-of-the-art solution and vapour phase detection of illicit drugs using luminescent sensing technologies, including materials and mechanisms.

Trifluoromethyl‐Substituted Perylene Diimides for Rapid and Sensitive Film‐Based Fluorescence Detection of Methamphetamine and Cocaine Hydrochloride

“…Film‐based luminescence sensors are promising for identifying chemical threats as they can combine rapid, trace and even reversible vapor detection in a portable device that is easy for first responders and law enforcement agencies to use. [ 10–12 ] Luminescence‐based sensing for trace level detection of explosive vapors is well advanced and has been commercialized. However, the development of luminescence‐based sensors for detecting illicit drugs is at an earlier stage.…”

Perylene Diimide Based Fluorescent Sensors for Drug Simulant Detection: The Effect of Alkyl-Chain Branching on Film Morphology, Exciton Diffusion, Vapor Diffusion, and Sensing Response

“…Such an approach has the advantages of high sensitivity, fast response, portability, and in some cases noncontact detection. − The luminescence detection of explosive analytes is based on a photoinduced electron transfer (PET) mechanism because many nitro-containing analytes have sufficiently high electron affinities (EAs) to oxidize the photoexcited sensing materials. , However, PET is unsuitable for detecting most illicit drugs, as they have low EAs due to the absence of strong electron withdrawing groups. In contrast, photoinduced hole transfer (PHT) can in principle be employed to detect drugs through luminescence quenching. − In this case, the sensing mechanism relies on the ionization potential (IP) of the photoexcited sensing material being sufficiently high to oxidize the drug, which leads to quenching of the luminescence. Physical interactions between the sensing and drug molecules are also critical in the quenching process because they need to be close enough to enable PHT to occur. , The role of analyte diffusion has been explored in the context of explosive vapor detection.…”

Utilizing Different Diffusion Mechanisms for Thin Film Fluorescence-Based Detection and Discrimination of Illicit Drug Vapors

“…Rather, illicit drugs tend to be composed of moieties with electrondonating groups, e.g., amines, and therefore, the small number of reports that use fluorescence-based detection to detect illicit drugs use the reverse detection process, namely, photoinduced hole transfer (PHT). 11 That is, the photoexcited sensing material oxidizes the illicit drug, which leads to the formation of a radical anion on the sensing material and a radical cation on the drug. The excited electron on the sensing material then transfers to the illicit drug, leaving the sensing material in the ground state.…”