Nanomaterials for the sensing of narcotics: Challenges and opportunities

In recent years, nanomaterials have become a rapidly developing material technology due to their numerous advantages (e.g., high surface area, tunable surface structures, and advanced optical/electrical/mechanical features) and tremendous potential in biomedical, environmental, and energy applications. Here, we offer a comprehensive review on the advances, challenges, and opportunities of nanomaterial-based sensing technology for narcotics. To this end, the synthesis and applicability of nanomaterials (e.g., carbon-based nanostructures, semiconductor nanoparticles, metal nanoparticles, and polymer nanostructures) for narcotics sensing are described in detail along with their diverse principles/mechanisms (e.g., electrochemical, colorimetric, fluorescent, surface plasmon resonance (SPR), and surface enhanced Raman spectroscopy (SERS)). Recent progress in the development of nanomaterials has been evaluated based on sensing performance (and operational conditions) including parameters related to efficiency, sensitivity, accuracy, precision, reusability, and economic viability. At last, this review offers prospects for the future research and development needed for nanomaterial-based sensing technology for the detection of narcotics.