Super-resolution imaging and statistical analysis of CdSe/CdS Core/Shell semiconductor nanocrystals

Core/shell nanoparticles in biomedical applications

Nanoparticles have several exciting applications in different areas and biomedial field is not an exception of that because of their exciting performance in bioimaging, targeted drug and gene delivery, sensors, and so on. It has been found that among several classes of nanoparticles core/shell is most promising for different biomedical applications because of several advantages over simple nanoparticles. This review highlights the development of core/shell nanoparticles-based biomedical research during approximately past two decades. Applications of different types of core/shell nanoparticles are classified in terms of five major aspects such as bioimaging, biosensor, targeted drug delivery, DNA/RNA interaction, and targeted gene delivery.

Super-resolving single nitrogen vacancy centers within single nanodiamonds using a localization microscope

In this paper, we show super-resolving single nitrogen vacancy (NV) centers with a sub-20 nanometer resolution in a wide-field localization microscope based on the discovery of photoluminescence blinking in high-pressure high-temperature nanodiamonds (NDs). The photon statistics reveals that NDs containing not only single but also multiple NV centers show photoluminescence blinking. The combination of an atomic force microscope and an optical localization microscope built on the blinking feature enables the optically resolved two NV centers within single NDs for the first time. Our method establishes new avenues for studying nanoscale photon dynamics associated with single NV centers within NDs together with ND-based ultra-sensitive bioimaging devices.

Luminescent nanoparticles and their applications in the life sciences

Nanoparticles have recently emerged as an important group of materials used in numerous disciplines within the life sciences, ranging from basic biophysical research to clinical therapeutics. Luminescent nanoparticles make excellent optical bioprobes significantly extending the capabilities of alternative fluorophores such as organic dyes and genetically engineered fluorescent proteins. Their advantages include excellent photostability, tunable and narrow spectra, controllable size, resilience to environmental conditions such as pH and temperature, combined with a large surface for anchoring targeting biomolecules. Some types of nanoparticles provide enhanced detection contrast due to their long emission lifetime and/or luminescence wavelength blue-shift (anti-Stokes) due to energy upconversion. This topical review focuses on four key types of luminescent nanoparticles whose emission is governed by different photophysics. We discuss the origin and characteristics of optical absorption and emission in these nanoparticles and give a brief account of synthesis and surface modification procedures. We also introduce some of their applications with opportunities for further development, which could be appreciated by the physics-trained readership.