Shingo Sotoma

Abstract Measuring temperature at or far from equilibrium at the nanoscale is important in many fields of science and engineering. A variety of luminescent nanothermometers have been developed in the past decade for the measurements. Fluorescent nanodiamonds (FNDs) stand out from the rest in terms of biological use, because the nanomaterials contain negatively charged nitrogen‐vacancy (NV − ) centers as photostable fluorophores and possess a number of remarkable properties including chemical ine

The physical/chemical states and properties of nanodiamonds subjected to thermal annealing and air oxidation, which are indispensable processes for the preparation of fluorescent nanodiamonds, were investigated.

The development of sensors to estimate physical properties, and their temporal and spatial variation, has been a central driving force in scientific breakthroughs. In recent years, nanosensors based on quantum measurements, such as nitrogen-vacancy centres (NVCs) in nanodiamonds, have been attracting much attention as ultrastable, sensitive, accurate and versatile physical sensors for quantitative cellular measurements. However, the nanodiamonds currently available for use as sensors have diamet

Highly stable lipid-encapsulated fluorescent nanodiamonds (FNDs) are produced by photo-crosslinking of diacetylene-containing lipids physically attached to the FND surface. Not only is this coating method simple and fast, but also it gives the FND-lipid hybrids favorable properties for bioapplications. The hybrids are useful as fluorescent biolabels as well as fiducial markers for correlative light and electron microscopy.

Abstract Applications of nanodiamonds (NDs) to bioimaging are restricted because of the nonspecific adsorption of biomolecules on the surface of NDs. Here, we show that hyperbranched polyglycerol-modified nanodiamond realizes both excellent dispersibility and marked suppression of nonspecific adsorption to proteins. Moreover, selective targeting to the proteins of interest, and the measurement of optically detected magnetic resonance from this nanodiamond on living cells are demonstrated.

The impeccable photostability of fluorescent nanodiamonds (FNDs) is an ideal property for use in fluorescence imaging of proteins in living cells. However, such an application requires highly specific labeling of the target proteins with FNDs. Furthermore, the surface of unmodified FNDs tends to adsorb biomolecules nonspecifically, which hinders the reliable targeting of proteins with FNDs. Here, we combined hyperbranched polyglycerol modification of FNDs with the β-lactamase-tag system to devel

Measuring physical quantities in the nanometric region inside single cells is of great importance for understanding cellular activity. Thus, the development of biocompatible, sensitive, and reliable nanobiosensors is essential for progress in biological research. Diamond nanoparticles containing nitrogen-vacancy centers (NVCs), referred to as fluorescent nanodiamonds (FNDs), have recently emerged as the sensors that show great promise for ultrasensitive nanosensing of physical quantities. FNDs e

We demonstrate that using hyperbranched polyglycerol, the surface modification of detonation-synthesized nanodiamonds produces stable monodispersed colloids in water. This colloid shows strong resi...

Nanoparticles play an active role in biomedical science due to their unique properties, which cannot be obtained from bulk materials. Therefore, understanding and controlling the physicochemical properties of nanoparticles are gaining increasing importance for their practical applications. Surface coating is an important technique that controls the physical properties of nanoparticles since the coating is the first part of the nanoparticle that is in contact with the environment. Additionally, t

Cathodoluminescence (CL) and correlative light‐electron microscopy (CLEM) are two useful analytical tools in diverse research areas. Recently, fluorescent nanodiamonds (FNDs) have emerged as promising imaging agents for both CL and CLEM owing to their exceptional photophysical and chemical properties. However, to realize their practical applications in the life sciences, surface modification and functionalization of the nanomaterials with bioactive molecules are critical and essential. Here we p

Gold nanoparticles (GNPs) are promising nanomaterials for various biomedical applications owing to their remarkable optical properties and biocompatibility. However, their interfacial properties require modification for practical use in such applications. Herein, a simple method for modifying the surface of GNPs with polydopamine (PDA) to serve as a scaffold for the subsequent polymerization of hyperbranched polyglycerol (HPG) is reported. GNPs were first coated with PDA (GNP-PDA), and then ring

Cationic polymers are often employed in conjugation with nanomaterials, and the resultant hybrids are useful for various bioapplications. Here, a single-step metal-free method for the synthesis of fluorescent nanodiamonds (FNDs) conjugated with cationic polymer brushes is reported. Distinct from the common methods such as atom transfer radical polymerization and reversible addition fragmentation chain transfer, our ring-opening-polymerization-based method is simple and less time consuming and ha

We report that carbon quantum dots (CQDs) synthesized via a hydrothermal process using anthraquinone derivatives and l-cysteine provide versatile detection modes, making them suitable for various experimental setups. By modification of the precursor structures, these CQDs can function as different types of fluorescent nanothermometers, including those based on fluorescence intensity, ratiometrics, and fluorescence lifetime. Notably, fluorescence lifetime-based CQDs demonstrate robust performance

Quantum sensors based on fluorescent nanodiamonds (FNDs) have emerged as potential nanosensors for measuring the physical parameters inside single cells due to their remarkable photostability and unique magneto-optical properties. Owing to the physicochemical inertness of FNDs, they can be hybridized with gold nanoparticles (FND–GNPs). This hybrid has unique applications, which cannot be realized by FNDs alone, such as two-in-one nanoheaters/thermometers. Nevertheless, the development of FND–GNP