Highly Stable and NIR Luminescent Ru-LPMSN Hybrid Materials for Sensitive Detection of Cu2+ in Vivo

Herein, new near-infrared (NIR) luminescent ruthenium complexes were prepared for detecting Cu²⁺ ions. Then, ruthenium complex hybrid nanomaterials (Ru-LPMSNs) were fabricated successfully by imbedding the ruthenium complex into mesoporous silica nanoparticles. Benefiting from the novel large-pore mesoporous structure and good adsorbility of LPMSNs, Ru-LPMSN hybrid materials showed a significantly enhanced fluorescence intensity and stability. NIR fluorescence of Ru-LPMSNs was rapidly quenched by Cu²⁺ ions. Ru-LPMSNs also showed high Cu²⁺ ion selectivity and sensitivity as a sensor. The detection limit of Cu²⁺ ions was 10 nM with a wide linear relationship between the fluorescence intensity of Ru-LPMSNs and the concentration of Cu²⁺ ions. The mechanism of fluorescence quenching might be that the combination of the ruthenium complex and Cu²⁺ ions constrained the photoinduced electron-transfer process. Furthermore, Ru-LPMSNs dramatically increased the fluorescence signals in cells and achieved Cu²⁺-ion detection. Ru-LPMSNs had different tissue affinities and could monitor distribution of exogenous Cu²⁺ ions in vivo. Moreover, Ru-LPMSNs realized direct and rapid detection of Cu²⁺-ion content in serum. These results indicated the potential applications of the prepared nanomaterials as Cu²⁺ detection agents.

Mitochondria Targeted Protein-Ruthenium Photosensitizer for Efficient Photodynamic Applications

Organelle-targeted photosensitization represents a promising approach in photodynamic therapy where the design of the active photosensitizer (PS) is very crucial. In this work, we developed a macromolecular PS with multiple copies of mitochondria-targeting groups and ruthenium complexes that displays highest phototoxicity toward several cancerous cell lines. In particular, enhanced anticancer activity was demonstrated in acute myeloid leukemia cell lines, where significant impairment of proliferation and clonogenicity occurs. Finally, attractive two-photon absorbing properties further underlined the great significance of this PS for mitochondria targeted PDT applications in deep tissue cancer therapy.

Fluorescence Sensing of Circulating Diagnostic Biomarkers Using Molecular Probes and Nanoparticles

The interplay of photonics, nanotechnology, and biochemistry has significantly improved the identification and characterization of multiple types of biomarkers by optical biosensors. Great achievements in fluorescence-based technologies have been realized, for example, by the advancement of multiplexing techniques or the introduction of nanoparticles to biochemical and clinical research. This review presents a concise overview of recent advances in fluorescence sensing techniques for the detection of circulating disease biomarkers. Detection principles of representative approaches, including fluorescence detection using molecular fluorophores, quantum dots, and metallic and silica nanoparticles, are explained and illustrated by pertinent examples from the recent literature. Advanced detection technologies and material development play a major role in modern biosensing and consistently provide significant improvements toward robust, sensitive, and versatile platforms for early detection of circulating diagnostic biomarkers.