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Utilizing metal nanoprobes with unique K‐edge identities to visualize complementary biological activities simultaneously can provide valuable information about complex biological processes. This study describes the design and preparation of an innovative pair of K‐edge metal nanoprobes and demonstrates the feasibility of their simultaneous quantitative detection using spectral photon‐counting computed tomography (SPCCT). Glycosaminoglycan (GAG) capped nanoparticles (ca. 15–20 nm) targeting two distinct components of the cartilage tissue, namely, aggrecan (acan) and aggrecanase (acanase) are designed and synthesized. These targeted nanoparticles comprised of praseodymium (Pr) and hafnium (Hf), with well‐separated K‐edge energies, enable simultaneous and ratiometric imaging of dual biomarkers in cartilage tissue. Following extensive physico‐chemical characterization of the ligand‐targeted particles, the feasibility of homing dual biomarkers in vitro is demonstrated. The material discrimination and simultaneous quantification of these targeted particles are also achieved and corroborated with inductively coupled plasmon spectroscopy. For the first time, the use of praseodymium is reported as a contrast agent for SPCCT imaging and demonstrates the ability to pair it with hafnium nanoprobes for multicontrast imaging of diseases. Importantly, the potential for ratiometric molecular imaging and tracking of osteoarthritis (OA) progression is shown with SPCCT K‐edge based imaging approach. [ABSTRACT FROM AUTHOR]

In recent years, emerging two-dimensional (2D) materials, such as molybdenum diselenide (MoSe2), have been at the center of attention for many researchers. This is due to their unique and fascinating physicochemical properties that make them attractive in space and defense applications that include shielding harsh irradiation environments. In this study, we examined the effects of gamma (γ) rays at various doses on the structural, chemical, and optical properties of MoSe2 layers. After the samples were exposed to intense gamma radiation (from a 60Co source) with various exposure times to vary the total accumulated dosage (up to 100 kGy), Raman and photoluminescence spectroscopies were used to study and probe radiation-induced changes to the samples. When compared to pristine materials, very few changes in optical properties were typically observed, indicating good robustness with little sensitivity, even at relatively high doses of gamma radiation. The imaging using scanning electron microscopy revealed a number of nano-hillocks that were connected to substrate alterations. X-ray photoelectron spectroscopies revealed that Mo's binding energies remained the same, but Se's binding energies blueshifted. We associated this shift with the decrease in Se vacancies that occurred after irradiation as a result of Mo atoms creating adatoms next to Se atoms. When compared to pristine materials, very few changes in optical, chemical, and structural properties were typically observed. These findings highlight the inherent resilience of MoSe2 in hostile radioactive conditions, which spurs additional research into their optical, electrical, and structural characteristics as well as exploration for potential space, energy, and defense applications. [ABSTRACT FROM AUTHOR]

This report entails the syntheses of morpholgically different silver molybdates by simple manipulation of experimental conditions (concentration variation and stirred/unstirred condition) using a stoppered glass vial under mild heat (-80 °C) treatment. We have elucidated for the first time the etching of robust hexagonal ammonium phosphomolybdate (APM) by silver nitrate (AgNO3) in an aqueous solution. Here meticulous manipulation of the experimental condition brings about three different morphologies: nanoflower (NF), nanowire (NW), and nanorod (NR) due to different recrystallization strategies and eventually identified an efficient catalyst. Among them, the last two also exhibit high morphological stability. In identical experimental conditions, while a lower APM concentration always (stirred/unstirred) yields NRs, a higher APM concentration, owing to slow diffusion, produces NFs from an unstirred solution and NWs from a well-stirred solution. The morphology is reliant on the concentration gradient of the Ag+ and the facile contact of the ions while etching APM. All the three different morphologies, once obtained, remain stable and are capable of acting as a nanocatalyst. But the tuned NF morphology as expected, owing to its hierarchical structure, showed the highest catalytic efficiency toward 3,3',5,5'-tetramethylbenzidine (TMB) oxidation. Explicit examination of the structures, stability, growth mechanism, and catalytic activity of the morphologically different molybdates along with their comparative colorimetric properties toward TMB oxidation in the presence of H2O2 is reported. Insightful investigation on the catalysis was executed with the representative NF which revealed efficient sulfide sensing capability in the presence of other common interfering anions and the result is significant. Syntheses of silver molybdates with different morphology and their application as a peroxidase mimic along with sulfide sensing ability. [ABSTRACT FROM AUTHOR]

Ultrathin 2D Co3O4 and Co3V2O8 nanosheets have been produced from our modified hydrothermal technique (MHT). Both the materials have been proved to be extraordinary electrode materials for pseudocapacitors. The neat nanosheets of Co3O4 and Co3V2O8 exhibit a record specific capacitance value of 1256 F g−1 and 4194 F g−1 at 1 A g−1 current density, respectively. [ABSTRACT FROM AUTHOR]

Modified hydrothermal route (MHT)-evolved Mn3O4 nanoparticles of ∼60 nm diameter were anchored onto a conductive multiwalled carbon nanotubes (MWCNTs) backbone (again under MHT) to produce an energy storage composite. To obtain the benefits of a low cost and stable MWCNT/Mn3O4 composite as a supercapacitor, cyclic voltammetry (CV) and galvanostatic charge–discharge measurements (GCD), as well as cycling stability and electrochemical impedance studies (EIS) have been performed. The electrochemical measurements reveal the suitability of the as-synthesized MWCNT/Mn3O4 composite as an electrode material with a highest specific capacitance of 441 F g−1 at 2 mV s−1 scan rate, which is 1.4 times higher than the specific capacitance (312 F g−1 at a scan rate of 2 mV s−1) of the bare Mn3O4 nanoparticle. MWCNT/Mn3O4 shows an excellent rate capability, outstanding long-term cyclic stability (98% capacity retention after 1000 consecutive cycles) and better power density and energy density. Due to the synergistic effect operating between the pseudocapacitor Mn3O4 nanoparticle and the conductive MWCNT, the capacitive performance of the composite electrode was considerably improved, and we perceive that the composite effect could have benefit in terms of supercapacitor application. These interesting improved material properties of the as-synthesized material indicate that the material is a suitable candidate for use in future energy storage applications. [ABSTRACT FROM AUTHOR]

In this work, we have disclosed the facile syntheses of morphologically diverse Cu 2 O nanoparticles using our laboratory designed modified hydrothermal reactor employing low-cost copper (II) acetate precursor compounds. The reaction conditions dovetail the effect of ethylene glycol (EG) and glucose to exclusively evolve the morphology tuned Cu 2 O nanomaterial at different pHs. The morphology tuning produces octahedron (Oh), dwarf hexapod (DHP), and elongated hexapod (EHP) Cu 2 O structures only with the optimized reagent concentrations. Interestingly, all of them were bestowed with a (111) facet, a superlative facet for facile nitroarene reduction. Thus, the morphology reliant catalytic reaction becomes evident. However, when used individually, EG and glucose evolve ill-defined CuO/Cu 2 O and Cu 2 O structures, respectively. We have observed that a change in pH of the medium at the onset of the reaction is obligatory for the evolution of tailor-made morphologically diverse Cu 2 O nanoparticles. However, preformed Cu 2 O particles do not suffer further structure/morphology changes under deliberate pH (6.0-9.0) change. With the as-obtained Oh, DHP, and EHP Cu 2 O structures, we further delve into the realm of catalysis to understand the splendor of the nanocatalyst, morphology and surface area dependence, facet selective reactivity, and other factors affecting the catalytic efficiency. The remarkable rate of catalysis of 4-nitrophenol (4-NP), evident from the catalyst activity parameter ( k a = 123.6 g -1 s -1 ), to produce 4-aminophenol in the presence of a reducing agent like sodium borohydride (NaBH 4 ) of the as-prepared catalysts is evidence of the collaborative effects of the effective surface area, surface positive charge, and active (111) facet of the Cu 2 O nanocatalyst. We have also studied the effect of other common anions, namely, Cl - , NO 2 - , NO 3 - , CO 3 2- , and SO 4 2- on the reduction process. To obtain a general consensus about facets, we compared (100) and (111) faceted Cu 2 O nanocatalysts not only for 4-NP reduction but also for the reduction of toxic chromium Cr(VI) in the presence of formic acid to further emphasize the importance of facet selectivity in catalysis and the versatility of the morphology tuned as-prepared Cu 2 O., Competing Interests: The authors declare no competing financial interest.