サブマイクロメートルスケール細胞膜研究の基盤技術

京都大学0048新制・課程博士博士(工学)甲第22464号工博第4725号新制||工||1738(附属図書館)京都大学大学院工学研究科分子工学専攻(主査)教授 梅田 眞郷, 教授 水落 憲和, 准教授 菅瀬 謙治学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDGA

Nanodiamonds for bioapplications - specific targeting strategies

Background: Nanodiamonds (NDs) provide a unique multitasking system for drug delivery and fluorescent imaging in biological environments. Owing to their quantum properties, NDs are expected to be employed as multifunctional probes in the future for the accurate visualization of biophysical parameters such as temperature and magnetic fields. However, the use of NDs for the selective targeting of the biomolecules of interest within a complicated biological system remains a challenge. One of the most promising solutions is the appropriate surface design of NDs based on organic chemistry and biochemistry. The engineered NDs have high biocompatibility and dispersibility in a biological environment and hence undergo cellular uptake through specific pathways. Scope of review: This review focuses on the selective targeting of NDs for biomedical and biophysical applications from the viewpoint of ND surface functionalizations and modifications. These pretreatments make possible the specific targeting of biomolecules of interest on or in a cell by NDs via a designed biochemical route.Major conclusions: The surface of a ND is covalently or noncovalently modified with silica, polymers, or biomolecules to reshape them, control their size, and enhance the colloidal stability and biomolecular selectivity toward biomolecules of interest. Electroporation, chemical treatment, injection, or endocytosis are the methods generally adopted to introduce a ND into living cells. The pathway, efficiency, and the cell viability depend on the selected method.General significance: In the biomedical field, surface modification facilitates specific delivery of a drug, leading to a higher therapeutic efficacy. In biophysical applications, surface modification paves the way for the accurate measurement of physical parameters to gain a better understanding of various cell functions

Non-contact Measurement of Internal Body Temperature Using Subcutaneously Implanted Diamond Microparticles

We constructed a highly sensitive fluorescence wide-field imager system with a microwave source, implanted fluorescent diamond microparticles (“microdiamonds”) subcutaneously into the dorsal skin of a mouse after sacrifice, and demonstrated the feasibility of using optically detected magnetic resonance (ODMR) to measure internal body temperature in a mammal

The Anomalous Formation of Irradiation Induced Nitrogen-Vacancy Centers in 5-Nanometer-Sized Detonation Nanodiamonds

Nanodiamonds containing negatively-charged Nitrogen-Vacancy (NV-) centers are versatile room-temperature quantum sensors in a growing field of research. Yet, knowledge regarding the formation mechanism in very small particles is still limited. Here, the study was focused on the formation of the smallest NV--containing diamonds, 5 nm detonation nanodiamonds (DNDs). As a reliable method to quantify NV- centers in nanodiamonds, half-field signals in electron paramagnetic resonance (EPR) spectroscopy are recorded. By comparing the NV- concentration in a series of nanodiamonds (5 - 100 nm), it was shown that the formation process in DNDs is unique in several aspects. NV- centers in DNDs are already formed during electron irradiation, without the need for high-temperature annealing. The effect was interpreted in terms of “self-annealing”, where size and type dependent effects enable vacancy migration at lower temperature. Although NV- concentration increases with particle size, the NV- concentration in NDs surpasses that of 20 nm-sized nanodiamonds. Using Monte-Carlo simulations, we show that the higher substitutional Nitrogen concentration compensates the vacancy loss induced by the large particle surface. Upon 1.5 × 1019 e-/cm2 electron irradiation, DNDs show a 12.5-fold NV- increment with no sign of saturation. These findings can be of interest for the creation of defects in other very small semiconductor nanoparticles

Investigation of irradiation induced nitrogen-vacancy centers in 5-nanometer-sized Detonation nanodiamonds

添付関連ファイル参照The 4th International Forum on Quantum Metrology and Sensin

Formation of Nitrogen-Vacancy centers in nanodiamonds: Dependence on Size and Type

ナノダイヤモンド中のNVセンターの形成に関する研究であり、ナノダイヤモンドの粒形と種類の依存性を調べた結果を発表する。ISMR APNMR NMRSJ SEST 202

Anomalous Formation of Irradiation-Induced Nitrogen-Vacancy Centers in 5 nm-Sized Detonation Nanodiamonds

Nanodiamonds containing negatively charged nitrogen-vacancy (NV−) centers are versatile room-temperature quantum sensors in a growing field of research. Yet, knowledge regarding the NV− formation mechanism in very small particles is still limited. This study focuses on the formation of the smallest NV−-containing diamonds, 5 nm detonation nanodiamonds (DNDs). As a reliable method to quantify NV− centers in nanodiamonds, half-field signals in electron paramagnetic resonance (EPR) spectroscopy are recorded. By comparing the NV− concentration with a series of nanodiamonds from high-pressure high-temperature (HPHT) synthesis (10−100 nm), it is shown that the formation process in 5 nm DNDs is unique in several aspects. NV− centers in DNDs are already formed at the stage of electron irradiation, without the need for high-temperature annealing, an effect related to the very small particle size. Also, the NV− concentration (in atomic ratio) in 5 nm DNDs surpasses that of 20 nm-sized nanodiamonds, which contradicts the observation that the NV− concentration generally increases with particle size. This can be explained by the 10 times higher concentration of substitutional nitrogen atoms in the studied DNDs ([NS ≈ 1000 ppm]) compared to the HPHT nanodiamonds ([NS ≈ 100 ppm]). Upon electron irradiation at a fluence of 1.5 × 10^19 e−/cm2, DNDs show a 12.5-fold increment in the NV− concentration with no sign of saturation reaching 1 out of about 80 DNDs containing an NV− center. These findings can be of interest for the creation of defects in other very small semiconductor nanoparticles beyond NV-nanodiamonds as quantum sensors.ISSN:1932-7455ISSN:1932-744

The Anomalous Formation of Radiation Induced Nitrogen-Vacancy Centers in 5-Nanometer-SizedDetonation Nanodiamonds

熱処理をすることなく電子線照射だけで5nmサイズのデトネーションダイヤモンド中にNVセンターが形成される現象について報告する。量子生命科学会 第3回大