Quantum cascade lasers (QCLs) operate in the mid-infrared range of the electromagnetic (EM) spectrum spanning wavelengths of approximately 3–15 micrometres. This range is of particular interest for gas detection and spectroscopy given that most chemical compounds exhibit so-called fundamental vibrational modes in this range. Typical semiconductor lasers exhibit a gap in the range of three to five micrometres. QCLs that cover this gap are thus particularly applicable for detection of hazardous substances and explosives in mass transit systems, airports and other public places. QCLs are compact, cost-effective devices operating at room temperature that exhibit fast response properties and high sensitivity. EU-funded researchers of the ‘Artificial nanomaterials for short wavelength emission in the infrared’ (Answer) project set out to develop a new class of materials to produce a continuous wave (CW) double channel QCL operating at wavelengths less than five micrometres for applications in homeland security. Industrial development and commercialisation of Answer concepts for novel nanomaterials to be used in QCLs have important implications not only for detection of hazardous substances potentially related to terrorist or other human threats in public places, but also to environmental detection of pollutants and even breath analysis for medical or law enforcement purposes. Answer results should advance Europe’s position in QCL technology and stimulate industrial development, spurring the EU economy while increasing the health and safety of its citizens.