Mechanistic Insights Into Nano-Enabled Forensic Sensing: Advanced Nanomaterial Platforms for Trace Evidence Detection

Forensic science relies on sensitive, selective, and reliable detection of trace evidence, often present in minute quantities within complex matrices. Traditional techniques, despite being well-established, are costly, time-consuming, and poorly suited for on-site analysis. Nanotechnology leverages unique physicochemical properties-high surface-to-volume ratio, quantum confinement, tunable optical/electronic behavior, and surface functionalization-to enhance forensic detection of drugs, explosives, gunshot residues, toxicants, DNA, and latent fingerprints. This review critically evaluates the mechanistic foundations, comparative performance, and translational potential of noble metal nanoparticles, carbon-based nanostructures, semiconductor quantum dots, metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and hybrid nano-composites. We discuss their roles in optical, electrochemical, catalytic, and surface-enhanced Raman scattering (SERS)-based systems, emphasizing field-deployable platforms, microfluidic integration, and portable devices. Key challenges including reproducibility, stability, safety, and legal admissibility are highlighted, providing a roadmap for next-generation forensic tools that bridge laboratory innovation with real-world applicability.