Aptamer functionalization and high-contrast reversible dual-color photoswitching fluorescence of polymeric nanoparticles for latent fingerprints imaging

Exploiting the intelligent stimuli-responsive fluorescent materials, which can selectively recognize lysozyme in fingerprints and enable high-contrast imaging, is still a challenge in latent fingerprints (LFPs) detection. Herein, based on Fluorescence Resonance Energy Transfer (FRET) mechanism, aptamer functionalization and high-contrast reversible dual-color photoswitching fluorescence of polymeric nanoparticles (LBA-RPFPNs) have been successfully constructed for efficient imaging of LFPs. Experiments results showed that LBA-RPFPNs displayed good water dispersibility, fast photo-responsiveness, favorable photoreversibility and good long-term stability. Of note, the aptamer possessed the ability of LBA-RPFPNs to target lysozyme in LFPs, thus realizing the selectivity of LFPs. Furthermore, the fluorescence of LBA-RPFPNs was reversibly switched between green and red through UV/visible light, achieving for high-contrast imaging of LFPs. This strategy provides good potential in disclosing the valuable information within LFPs.