Photoluminescent carbon nanomaterials for sensing of illicit drugs: focus

Abstract

The growth of illicit drugs is a serious social problem, putting great pressure on law enforcement officers to screen numerous suspicious samples at crime scenes. Although commercial colorimetric kits are available, they are limited to common illicit drugs. With increasing numbers of new psychoactive substances in the market, accurate and rapid screening assays are highly demanded. Carbon dots (C-dots) are photoluminescent (PL) carbon nanomaterials with unique properties of excellent stability against salt and photo-irradiation, low blinking, and biocompatibility. They can be prepared easily through various routes from numerous precursors.This Focus provides examples of C-dots based PL assays for screening illicit drugs. The drugs induce PL changes of C-dots mostly through electron transfer and energy transfer. Liquid-and solid-phase PL assays of C-dots can be applied for in-field screening, with advantages of rapidity, low cost, selectivity, and minimum color interference showing their great commercial potential.

Electrochemical Sensors, Biosensors, and Optical Sensors for the Detection of Opioids and Their Analogs: Pharmaceutical, Clinical, and Forensic Applications

“…This advancement effectively addresses the challenges of identifying illicit drugs in intricate biological samples, presenting enhanced functionality and dependability. Incorporation of nanomaterials, such as metal nanoparticles [133][134][135], carbon nanomaterials [136,137], and quantum dots [138], has dramatically enhanced the sensitivity of colorimetric sensors. Nanomaterials provide a large surface area for interactions with target analytes, leading to increased signal amplification and improved sensor response at lower concentrations of opioids.…”

Luminescence-based detection and identification of illicit drugs

“…40,41 Luminescence-based sensors have been widely studied for the detection of explosives, 40,42 hazardous chemicals, 43,44 and biological species, 45,46 with the chemical of interest being in solution, solid, or vapour phase. Luminescent sensors composed of small molecules, [47][48][49] aptamers, [50][51][52][53][54][55][56] and nanomaterials, [57][58][59][60][61] developed for sensing and differentiating illicit drugs in solutions such as drinks 47,62 and biofluids. 48,55 In contrast, the development of luminescence-based detection of illicit drug vapours is still at an early stage for several reasons: (1) the low vapour pressures of most drugs, especially in salt form creates an issue of sensitivity; 12,13 (2) the difficulty of discriminating an illicit drug from potential interferants in the vapour phase gives rise to issues relating to selectivity; 8,63 and (3) the lack of understanding of the process behind the sensing response (turn-on, turn-off, colour change) of the luminescent materials (usually a film) when exposed to drug vapours, and the physical interactions between the drug and the sensing material.…”

Advances in the application of novel carbon nanomaterials in illicit drug detection

“…One is fluorescent chemical sensors, which detect substances through changes in their fluorescence signals. Because of the presence of many hydrophilic functional groups (including hydroxyl, amino, and carboxylic acid groups) on the surface of the bare C-dots, C-dots are highly dispersible in aqueous solutions, 31 and can interact with drug-specific groups to achieve the analytical screening of illicit drugs. The second category is fluorescent biosensors based on the principle that bioactive substances have selective recognition functions, usually combined with molecularly imprinted polymer, antibody, and aptamer technologies to achieve drug-specific recognition.…”