Water-dispersed luminescent quantum dots for miRNA detection

This review targets valuable insight into the application of water dispersed luminescent quantum dots (QDs) for detection of microRNA (miRNA). Recently, considerable efforts have been devoted to obtain QDs for biosensing and bioimaging. Quantum dots with bright stable photoluminescence, synthesized directly in the water phase, offered an unparalleled advantage for the assay development involving small size, high colloidal stability, and presence of groups for bioconjugation. In this review we have delineated the fundamental principles guiding the rational design, synthesis, and application of photoluminescent water-dispersed QDs. Diverse analysis methods for miRNA detection based on the photoluminescence,electrochemiluminescence, Forster resonance energy transfer and electrochemiluminescence energy transfer with different enhancement strategies are discussed

Luminescent Composite Carbon/SiO2 Structures: Synthesis and Applications

Luminescent carbon nanostructures (CNSs) have attracted great interest from the scientific community due to their photoluminescent properties, structural features, low toxicity, and a great variety of possible applications. Unfortunately, a few problems hinder their further development. These include the difficulties of separating a mixture of nanostructures after synthesis and the dependence of their properties on the environment and the aggregate state. The application of a silica matrix to obtain luminescent composite particles minimizes these problems and improves optical properties, reduces photoluminescence quenching, and leads to wider applications. We describe two methods for the formation of silica composites containing CNSs: inclusion of CNSs into silica particles and their grafting onto the silica surface. Moreover, we present approaches to the synthesis of multifunctional particles. They combine the unique properties of silica and fluorescent CNSs, as well as magnetic, photosensitizing, and luminescent properties via the combination of functional nanoparticles such as iron oxide nanoparticles, titanium dioxide nanoparticles, quantum dots (QDs), and gold nanoclusters (AuNCs). Lastly, we discuss the advantages and challenges of these structures and their applications. The novelty of this review involves the detailed description of the approaches for the silica application as a matrix for the CNSs. This will support researchers in solving fundamental and applied problems of this type of carbon-based nanoobjects