Advances in nanomaterials applied to crime combat and prevention

The field of nanomaterials has experienced an unprecedented development within the past few years, with applications expanding across multiple fields such as medicine, agriculture, or energy. One of the most crucial applications is crime combat and prevention, where the new advances in nanotechnology can offer an effective prevention, as well as fast identification of criminals. However, the number of reported works in this field has been limited due to the intrinsic multidisciplinary nature of crime prevention, which requires field-specific knowledge of criminal processes and technical expertise in material and chemical sciences. This manuscript reviews for the first time the current advances of nanomaterials applied to crime combat and prevention. Despite the wide range of potential applications of nanomaterials, we focused on five main fields: sensors for illegal substances, anti-graffiti coatings, UV-taggants, fingerprint recovery and protective vests. In the case of sensors for illegal substances, the detection of multiple compounds ranging from DNA, toxins and explosives working on different principles (i.e. electrochemical, optical) have been described. These fields were chosen given their high relevance in current crime activities. Initially, an overview of the different types of nanomaterials that have been incorporated in the field (i.e. metallic, ceramic, or 2D materials) is provided. The relevance of their use on the different applications is then explained from a practical point of view, and a comparison with current gold standards is offered. For each application, the latest developments in nanotechnology were described, and the advantages of the nanomaterials compared to standard approaches have been studied. Limitations and opportunities of current approaches are also discussed, to offer an overview of the current landscape, and indicate future directions of the field.