AIEE-Active Green Fluorescence Imaging Technique for Latent Fingerprint Application.

Latent fingerprint imaging is a crucial tool for national security and crime recognition, requiring environmentally sustainable, nontoxic materials. To address this need, we have developed a green fluorescence-emitting material, THCHO, that binds effectively to latent fingerprints, enabling clear, high-resolution visualization. The solution produces strong green fluorescence that highlights fingerprint imprints with exceptional detail and contrast. The material is applicable across various substrates, making it efficient for on-site visualization. The synthesized organic conjugated material THCHO rapidly visualizes precise fingerprint substructures within 5 s using a simple spray method. It maintains high contrast and low interference across different substrates, such as glass, aluminum foil, plastic, and ironware, even in diverse backgrounds. Additionally, the THCHO material demonstrates high stability, retaining its fluorescence imaging capabilities for up to 35 days and after water washing. This is the first report of using a conjugated organic thiophene material for latent fingerprint fluorescence imaging, suggesting potential applications in other fields.