Diverse Nanoassemblies of Graphene Quantum Dots and Their Mineralogical Counterparts

Complex structures from nanoparticles are found in rocks, soils, and sea sediments but the mechanisms of their formation are poorly understood, which causes controversial conclusions about their genesis. Here we show that graphene quantum dots (GQDs) can assemble into complex structures driven by coordination interactions with metal ions commonly present in environment and serve a special role in Earth’s history, such as Fe3+ and Al3+. GQDs self- assemble into mesoscale chains, sheets, supraparticles, nanoshells, and nanostars. Specific assembly patterns are determined by the effective symmetry of the GQDs when forming the coordination assemblies with the metal ions. As such, maximization of the electronic delocalization of Ï - orbitals of GQDs with Fe3+ leads to GQD- Fe- GQD units with D2 symmetry, dipolar bonding potential, and linear assemblies. Taking advantage of high electron microscopy contrast of carbonaceous nanostructures in respect to ceramic background, the mineralogical counterparts of GQD assemblies are found in mineraloid shungite. These findings provide insight into nanoparticle dynamics during the rock formation that can lead to mineralized structures of unexpectedly high complexity.Komplexe Strukturen aus Nanopartikeln sind in Gesteinen, Böden und Meeressedimenten zu finden, aber die Mechanismen ihrer Entstehung sind kaum verstanden. Es wird gezeigt, dass sich Graphenquantenpunkte (GQDs) zu komplexen Strukturen zusammenfügen können, angetrieben durch Koordinationswechselwirkungen mit Metallionen wie Fe3+ and Al3+, die in der Umwelt häufig vorkommen und eine besondere Rolle in der Erdgeschichte spielen.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155470/1/ange201908216.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155470/2/ange201908216_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155470/3/ange201908216-sup-0001-misc_information.pd

Diverse Nanoassemblies of Graphene Quantum Dots and Their Mineralogical Counterparts

Complex structures from nanoparticles are found in rocks, soils, and sea sediments but the mechanisms of their formation are poorly understood, which causes controversial conclusions about their genesis. Here we show that graphene quantum dots (GQDs) can assemble into complex structures driven by coordination interactions with metal ions commonly present in environment and serve a special role in Earth’s history, such as Fe3+ and Al3+. GQDs self- assemble into mesoscale chains, sheets, supraparticles, nanoshells, and nanostars. Specific assembly patterns are determined by the effective symmetry of the GQDs when forming the coordination assemblies with the metal ions. As such, maximization of the electronic delocalization of Ï - orbitals of GQDs with Fe3+ leads to GQD- Fe- GQD units with D2 symmetry, dipolar bonding potential, and linear assemblies. Taking advantage of high electron microscopy contrast of carbonaceous nanostructures in respect to ceramic background, the mineralogical counterparts of GQD assemblies are found in mineraloid shungite. These findings provide insight into nanoparticle dynamics during the rock formation that can lead to mineralized structures of unexpectedly high complexity.Complex structures from nanoparticles are found in rocks, soils, and sea sediments but the mechanisms of their formation are poorly understood. It is shown that graphene quantum dots (GQDs) can assemble into complex structures driven by coordination interactions with metal ions commonly present in the environment and play a special role in Earth’s history, such as Fe3+ and Al3+.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155475/1/anie201908216_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155475/2/anie201908216.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155475/3/anie201908216-sup-0001-misc_information.pd

Emergence of complexity in hierarchically organized chiral particles

The structural complexity of composite biomaterials and biomineralized particles arises from the hierarchical ordering of inorganic building blocks over multiple scales. Although empirical observations of complex nanoassemblies are abundant, the physicochemical mechanisms leading to their geometrical complexity are still puzzling, especially for nonuniformly sized components. We report the self-assembly of hierarchically organized particles (HOPs) from polydisperse gold thiolate nanoplatelets with cysteine surface ligands. Graph theory methods indicate that these HOPs, which feature twisted spikes and other morphologies, display higher complexity than their biological counterparts. Their intricate organization emerges from competing chirality-dependent assembly restrictions that render assembly pathways primarily dependent on nanoparticle symmetry rather than size. These findings and HOP phase diagrams open a pathway to a large family of colloids with complex architectures and unusual chiroptical and chemical properties

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Frontispiz: Diverse Nanoassemblies of Graphene Quantum Dots and Their Mineralogical Counterparts

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155477/1/ange202082262.pd

Frontispiece: Diverse Nanoassemblies of Graphene Quantum Dots and Their Mineralogical Counterparts

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155530/1/anie202082262.pd

Colorimetric Detection of Carcinogenic Aromatic Amine Using Layer-by-Layer Graphene Oxide/Cytochrome <i>c</i> Composite

Graphene and its derivatives were found to be efficient modulators of enzymes in various systems. However, the modulating mechanism was not well discussed for long time. Inspired by the artificial enzyme-enhancing property of graphene oxide (GO) toward cytochrome <i>c</i> (cyt. <i>c</i>), we have successfully fabricated a protein/GO hybrid structure via a layer-by-layer (LbL) strategy. The obtained LbL assemblies showed great enhancement in peroxidase activity of cyt. <i>c</i>, as well as excellent stability, resistance to extreme environment change, and also possibility for recycling by simple centrifugation without any obvious activity loss. The LbL cyt. <i>c</i>/GO hybrids were expanded to a colorimetric sensing system for the detection of carcinogenic aromatic amines. The probe showed high sensitivity and selectivity for aromatic amines over various competing soluble aromatic compounds and could be determined by the naked eye or portable devices. The working mechanism was well studied through kinetic evaluation, experimental characterization, and molecular dynamics simulations. This work does not only introduce a new graphene/protein hybrid material or a rapid and sensitive visualization of carcinogenic aromatic amines, but also spread the practical application of biomolecule–graphene interface strategy and further give a better understanding of the interaction of graphene and protein

Metal‐Bridged Graphene–Protein Supraparticles for Analog and Digital Nitric Oxide Sensing

Self- limited nanoassemblies, such as supraparticles (SPs), can be made from virtually any nanoscale components, but SPs from nanocarbons including graphene quantum dots (GQDs), are hardly known because of the weak van der Waals attraction between them. Here it is shown that highly uniform SPs from GQDs can be successfully assembled when the components are bridged by Tb3+ ions supplementing van der Waals interactions. Furthermore, they can be coassembled with superoxide dismutase, which also has weak attraction to GQDs. Tight structural integration of multilevel components into SPs enables efficient transfer of excitonic energy from GQDs and protein to Tb3+. This mechanism is activated when Cu2+ is reduced to Cu1+ by nitric oxide (NO)- an important biomarker for viral pulmonary infections and Alzheimer’s disease. Due to multipronged fluorescence enhancement, the limit of NO detection improves 200 times reaching 10 Ã 10- 12 m. Furthermore, the uniform size of SPs enables digitization of the NO detection using the single particle detection format resulting in confident registration of as few as 600 molecules mL- 1. The practicality of the SP- based assay is demonstrated by the successful monitoring of NO in human breath. The biocompatible SPs combining proteins, carbonaceous nanostructures, and ionic components provide a general path for engineering uniquely sensitive assays for noninvasive tracking of infections and other diseases.Graphene quantum dots (GQDs) can assemble into self- limited supraparticles when van der Waals forces are supplemented by coordination bonds with Tb3+ ions. Superoxide dismutase (SOD) is incorporated into supraparticles, which enables a selective assay for nitric oxide (NO) with ultrahigh sensitivity. Practical for NO detection in exhaled breath, a rapid non- invasive test is approached for pulmonary inflammation, such as coronavirus pneumonia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/168383/1/adma202007900_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/168383/2/adma202007900.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/168383/3/adma202007900-sup-0001-SuppMat.pd