Photoluminescent carbon nanomaterials for sensing of illicit drugs: focus.

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.