<p>Recent advances in forensic science highlight the emerging role of nanotechnology and sensor-based systems in enhancing diagnostic accuracy and sensitivity. These two techniques, though complementary, offer distinct mechanisms of action that innovate the forensic investigations. Advances in nanomaterial-based assays for biological fluid analysis enable rapid, reliable molecular-level detection, thereby improving the accuracy of forensic diagnostics. Carbon-based nanomaterials, including graphene, carbon dots, and carbon nanotubes, are increasingly exploited for their tunable optical, electrochemical, and surface properties, which enable ultrasensitive detection of illicit drugs, explosive residues, toxic metals, and trace biomolecules, while also enhancing latent fingerprint visualisation. Parallel advances in sensor engineering have enabled highly selective optical, electrochemical, and biosensing systems capable of detecting minute forensic evidence directly at crime scenes. Carbon nanomaterial-based sensing platforms have significantly advanced forensic science by addressing the limitations of conventional analytical techniques, particularly in terms of sensitivity, portability, and response time. The incorporation of these nanomaterials with miniaturised, digitally integrated sensing devices has shifted forensic analysis toward real-time, on-site decision making, reducing reliance on centralised laboratories and minimising sample degradation and handling errors. This review examines recent progress in materials, such as carbon and its derivatives, sensing strategies, and application-specific performance metrics, and highlights current challenges and unmet needs in forensic applications. Collectively, these developments underscore the growing role of nanomaterials-based sensing technologies in strengthening evidentiary reliability and advancing modern forensic investigations.</p> Graphical abstract