Time-Gated Imaging of Latent Fingerprints and Specific Visualization of Protein Secretions via Molecular Recognition

Persistent nanophosphors can remain luminescent after excitation ceases; thus, they offer a promising way to avoid background fluorescence interference in bioimaging. In this work, Zn₂GeO₄:Ga,Mn (ZGO:Ga,Mn) persistent luminescence nanoparticles were developed and they were employed for time-gated imaging of latent fingerprints (LFP). The nanoparticles were functionalized with a carboxyl group and utilized to label LFP through reacting with the amino group in the LFP. Results proved the potent ability of ZGO:Ga,Mn in eliminating background fluorescence to afford highly sensitive LFP imaging. Moreover, LFP aged for 60 days were successfully detected due to the presence of highly stable amino acids. After being functionalized with concanavalin A, the nanoparticles achieved visualization of glycoproteins in LFP. This strategy provides great versatility in LFP imaging and good potential in uncovering the chemical information within LFP, making it valuable in forensic investigations and medical diagnostics

Autofluorescence-Free Targeted Tumor Imaging Based on Luminous Nanoparticles with Composition-Dependent Size and Persistent Luminescence

Optical bioimaging is an indispensable tool in modern biology and medicine, but the technique is susceptible to autofluorescence interference. Persistent nanophosphors provide an easy-to-perform and highly efficient means to eliminate tissue autofluorescence. However, direct synthesis of persistent nanophosphors with tunable properties to meet different bioimaging requirements remains largely unexplored. In this work, zinc gallogermanate (Zn_1+<i>x</i>Ga_{2–2<i>x</i>}Ge_<i>x</i>O₄:Cr, 0 ≤ <i>x</i> ≤ 0.5, ZGGO:Cr) persistent luminescence nanoparticles with composition-dependent size and persistent luminescence are reported. The size of the ZGGO:Cr nanoparticles gradually increases with the increase of <i>x</i> in the chemical formula. Moreover, the intensity and decay time of persistent luminescence in ZGGO:Cr nanoparticles can also be fine-tuned by simply changing <i>x</i> in the formula. <i>In vivo</i> bioimaging tests demonstrate that ZGGO:Cr nanoparticles can efficiently eliminate tissue autofluorescence, and the nanoparticles also show good promise in long-term bioimaging as they can be easily reactivated <i>in vivo</i>. Furthermore, an aptamer-guided ZGGO:Cr bioprobe is constructed, and it displays excellent tumor-specific accumulation. The ZGGO:Cr nanoparticles are ideal for autofluorescence-free targeted bioimaging, indicating their great potential in monitoring cellular networks and construction of guiding systems for surgery

One-Dimensional Luminous Nanorods Featuring Tunable Persistent Luminescence for Autofluorescence-Free Biosensing

Persistent luminescence nanoparticles (PLNPs), which can remain luminescent after cessation of excitation, have emerged as important materials in biomedicine due to their special ability to eliminate tissue autofluorescence. Even though significant advances have been made in bioimaging, studies on controlled synthesis of PLNPs with tunable properties are lacking. Until now, only a few studies have reported the synthesis of quasi-spherical ZnGa₂O₄:Cr PLNPs, and direct synthesis of PLNPs with other shapes and chemical compositions has not been reported. Herein, we report the direct synthesis of Zn₂GeO₄:Mn (ZGO:Mn) persistent luminescence nanorods (NRs). The length and persistent luminescence of ZGO:Mn NRs can be fine-tuned by simply changing the pH of the hydrothermal reaction system. Moreover, ZGO:Mn NRs exhibit rapid growth rate, and NRs with strong persistent luminescence can be obtained within 30 min of hydrothermal treatment. Aptamer-guided ZGO:Mn bioprobes were further constructed and applied to serum lysozyme analysis. Serum samples from patients with lung cancer, gastric cancer, and colorectal cancer were collected, and the concentrations of lysozyme in these samples were determined. Since the bioprobes displayed long persistent luminescence, serum autofluorescence interference was completely eliminated. The lysozyme quantification results were in good agreement with those obtained using a clinical method, suggesting the good potential of the bioprobes in the analysis of clinical samples. The developed ZGO:Mn NRs possess tunable length and persistent luminescence, and they are ideal for eliminating autofluorescence interference in biosensing, making them valuable in research areas such as studying the functions of biomolecules and monitoring of molecular/cellular networks in their native contexts