Publications by authors named "Bohan Shan"

The complexity of serum constituents and the lack of knowledge on biomarkers bring obstacles for reliable cancer screening with the limited information obtained by surface-enhanced Raman scattering (SERS) on a single substrate. We report here an extremely high-accurate approach for cancer screening by biomarker-free serum-SERS technique which employs three principal SERS substrates that are of specially designed surface properties. With three substrates rich information on serum can be obtained from SERS spectra, of which quadratic discriminant analysis (QDA) yields excellent classifications of serum samples independently.

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A modulated bi-phase synthesis towards large-scale manganese 1,4-benzenedicarboxylate (MnBDC) MOFs with a precise control over their morphology (bulk vs. layered) is presented. Metal precursors and organic ligands are separated to reduce the kinetic reaction rates for better control over the crystallization process.

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The application of high pressure allows control over the unit cell and interatomic spacing of materials without any need for new growth methods or processing while accessing their materials properties in situ. Under these extreme pressures, materials may assume new structural phases and reveal novel properties. Here, unusual phase transition and band renormalization effects in 2D van der Waals Ruddlesden-Popper hybrid lead halide perovskites, which have shown extraordinary optical properties and immense potential in light emission and conversion technologies, are reported.

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Large-scale synthesis of van der Waals (vdW) metal-organic framework (MOF) nanosheets with controlled crystallinity and interlayer coupling strength is one of the bottlenecks in 2D materials that has limited its successful transition to large-scale applications. Here, scalable synthesis of mBDC (m = Zn and Cu) 2D MOFs at large scales through a biphase method is demonstrated. The results show replacing water molecules with pyridine eliminates hydrogen bond formation at metal cluster sites.

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The quality of nanoparticle dispersion in a polymer matrix significantly influences the macroscopic properties of the composite material. Like general polymer-nanoparticle composites, electrospun nanofiber nanoparticle composites do not have an adopted quantitative model for dispersion throughout the polymer matrix, often relying on a qualitative assessment. Being such an influential property, quantifying dispersion is essential for the process of optimization and understanding the factors influencing dispersion.

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Developing electrospun nanofiber/nanoparticle composites (ENNCs) is an emerging strategy for immobilizing functional particles for a variety of applications. The radial location of the particle along the fiber, either at the surface or in the bulk, has implication into the resulting properties. To explore particle location along fibers, ZIF-8 impregnated poly(ethylene oxide) (PEO) nanofibers are formed by electrospinning particle suspensions.

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Systematic studies of key operating parameters for the sonochemical synthesis of the metal organic framework (MOF) HKUST-1(also called CuBTC) were performed including reaction time, reactor volume, sonication amplitude, sonication tip size, solvent composition, and reactant concentrations analyzed through SEM particle size analysis. Trends in the particle size and size distributions show reproducible control of average particle sizes between 1 and 4μm. These results along with complementary studies in sonofragmentation and temperature control were conducted to compare these results to kinetic crystal growth models found in literature to develop a plausible hypothetical mechanism for ultrasound-assisted growth of metal-organic-frameworks composed of a competitive mechanism including constructive solid-on-solid (SOS) crystal growth and a deconstructive sonofragmentation.

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