Preparation of Aptamer-functionalized Au@pNTP@SiO2 Core-Shell Surface-enhanced Raman Scattering Probes for Raman Imaging Study of Adhesive Tape Transferred-Latent Fingerprints

Abstract The core-shell SERS nanoprobe combined with adhesive tape was used to recognize the latent fingerprints on the surface of the object, which provides an effective solution for the imaging of latent fingerprints on the surface of large immobile or curved objects. First, the Au@pNTP@SiO 2 SERS probes modified by aptamers specific to lysozyme were prepared, and characterized by TEM/EDS, and its SERS effects were also tested. Then the probe was incubated with the aged-latent fingerprints on the surface of different objects. Afterwards, the dried latent fingerprint with modified SERS probes was transferred to the adhesive tape and imaged under the confocal Raman microscope. The results showed that the size distribution of the core-shell SERS probe was uniform, which was mostly concentrated in 60 nm, leading to excellent stability and dispersity. The SERS probe also had strong SERS intensity and reproducibility with the characteristic peaks at 723, 855, 1081, 1343 and 1572 cm −1 , which were consistent with the previous reports. When applying such SERS probe into the tape-transferred latent fingerprint's imaging, not only the primary structure (pattern) but also the secondary structure (forking and ring points) and the third-level structure of fingerprint (sweat pore) could be clearly observed. The successful development of the SERS imaging of transferred latent fingerprint on adhesive tapes combined with the aptamer-functionalized SERS probe provides an effective method for recognizing latent fingerprints in forensic science, which also has the potential applications in the other areas such as food safety and public safety testing.