Self-Assembly of Nanodiamonds and Plasmonic Nanoparticles for Nanoscopy

Nanodiamonds in biomedical research: Therapeutic applications and beyond

Nanodiamonds (NDs) comprise a family of carbon-based nanomaterials (i.e. diameter <100 nm) with the same sp3 lattice structure that gives natural diamonds their exceptional hardness and electrical insulating properties. Among all carbon nanomaterials-e.g. carbon nanotubes, nanodots, and fullerenes-NDs are of particular interest for biomedical applications because they offer high biocompatibility, stability in vivo, and a dynamic surface chemistry that can be manipulated to perform a seemingly limitless variety of ultra-specific tasks. NDs are already deepening our understanding of basic biological processes, while numerous laboratories continue studying these nanomaterials with an aim of making seismic improvements in the prevention, diagnosis, and treatment of human diseases. This review surveys approximately 2,000 the most recent articles published in the last 5 years and includes references to more than 150 of the most relevant publications on the biomedical applications of NDs. The findings are categorized by contemporary lines of investigation based on potential applications, namely: genetics and gene editing, drug delivery systems, neural interfacing, biomedical sensors, synthetic biology, and organ and tissue regeneration. This review also includes a brief background of NDs and the methods currently developed for their synthesis and preparation. Finally, recommendations for future investigations are offered.

Multiple Bioimaging Applications Based on the Excellent Properties of Nanodiamond: A Review

Nanodiamonds (NDs) are emerging as a promising candidate for multimodal bioimaging on account of their optical and spectroscopic properties. NDs are extensively utilized for bioimaging probes due to their defects and admixtures in their crystal lattice. There are many optically active defects presented in NDs called color centers, which are highly photostable, extremely sensitive to bioimaging, and capable of electron leap in the forbidden band; further, they absorb or emit light when leaping, enabling the nanodiamond to fluoresce. Fluorescent imaging plays a significant role in bioscience research, but traditional fluorescent dyes have some drawbacks in physical, optical and toxicity aspects. As a novel fluorescent labeling tool, NDs have become the focus of research in the field of biomarkers in recent years because of their various irreplaceable advantages. This review primarily focuses on the recent application progress of nanodiamonds in the field of bioimaging. In this paper, we will summarize the progress of ND research from the following aspects (including fluorescence imaging, Raman imaging, X-ray imaging, magnetic modulation fluorescence imaging, magnetic resonance imaging, cathodoluminescence imaging, and optical coherence tomography imaging) and expect to supply an outlook contribution for future nanodiamond exploration in bioimaging.

Paper-Based Substrate for a Surface-Enhanced Raman Spectroscopy Biosensing Platform-A Silver/Chitosan Nanocomposite Approach

Paper is a popular platform material in all areas of sensor research due to its porosity, large surface area, and biodegradability, to name but a few. Many paper-based nanocomposites have been reported in the last decade as novel substrates for surface-enhanced Raman spectroscopy (SERS). However, there are still limiting factors, like the low density of hot spots or loss of wettability. Herein, we designed a process to fabricate a silver-chitosan nanocomposite layer on paper celluloses by a layer-by-layer method and pH-triggered chitosan assembly. Under microscopic observation, the resulting material showed a nanoporous structure, and silver nanoparticles were anchored evenly over the nanocomposite layer. In SERS measurement, the detection limit of 4-aminothiophenol was 5.13 ppb. Furthermore, its mechanical property and a strategy toward further biosensing approaches were investigated.