Jiechao Ge

A New Nanobiosensor for Glucose with High Sensitivity and Selectivity in Serum Based on Fluorescence Resonance Energy Transfer (FRET) between CdTe Quantum Dots and Au Nanoparticles

A novel assembled nanobiosensor QDs-ConA-beta-CDs-AuNPs was designed for the direct determination of glucose in serum with high sensitivity and selectivity. The sensing approach is based on fluorescence resonance energy transfer (FRET) between CdTe quantum dots (QDs) as an energy donor and gold nanoparticles (AuNPs) as an energy acceptor. The specific combination of concanavalin A (ConA)-conjugated QDs and thiolated beta-cyclodextrins (beta-SH-CDs)-modified AuNPs assembles a hyperefficient FRET nanobiosensor. In the presence of glucose, the AuNPs-beta-CDs segment of the nanobiosensor is displaced by glucose which competes with beta-CDs on the binding sites of ConA, resulting in the fluorescence recovery of the quenched QDs. Experimental results show that the increase in fluorescence intensity is proportional to the concentration of glucose within the range of 0.10-50 muM under the optimized experimental conditions. In addition, the nanobiosensor has high sensitivity with a detection limit as low as 50 nM, and has excellent selectivity for glucose over other sugars and most biological species present in serum. The nanobiosensor was applied directly to determine glucose in normal adult human serum, and the recovery and precision of the method were satisfactory. The unique combination of high sensitivity and good selectivity of this biosensor indicates its potential for the clinical determination of glucose directly and simply in serum, and provides the possibility to detect low levels of glucose in single cells or bacterial cultures. Moreover, the designed nanobiosensor achieves direct detection in biological samples, suggesting the use of nanobiotechnology-based assembled sensors for direct analytical applications in vivo or in vitro.

Sol–solvothermal synthesis and microwave evolution of La(OH)3 nanorods to La2O3 nanorods

Solvothermal synthesis of La(OH)3 sol and microwave radiation drying of La(OH)3 nanorods were employed for the first time to synthesize La2O3 nanorods with diameters around 10 nm and lengths up to 200 nm. The resulting products were characterized with XRD, TEM and HRTEM. Microwave radiation drying was found to be more effective to maintain the morphologies of nanorods than conventional drying.

A rapid hydrothermal route to sisal-like 3D ZnO nanostructures via the assembly of CTA+ and Zn(OH)42−: growth mechanism and photoluminescence properties

A 3D ZnO nanostructure with sisal-like morphology has been synthesized in the temperature range 120–220u2009°C by a rapid hydrothermal route (30xa0min) via the assembly of CTA+ and Zn(OH)42−. The obtained samples are hexagonal wurtzite structures and they exhibit special optical properties with a red-shift of about 20xa0nm compared to the corresponding nanorods and nanowires. The sisal, constructed of many nanorods, possesses typical tapering features with tip size 80–100xa0nm. The effects of CTAB, NaOH, reaction time and temperature were investigated. Results show that the concentration of CTAB and Zn2+/OH− molar ratio play important roles in the fabrication of uniform and pure ZnO samples. On the basis of structural information provided by XRD, SEM, TEM, and HRTEM, a growth mechanism is proposed for the formation of sisal-like 3D ZnO nanostructures.

The fabrication of La(OH)3 nanospheres by a controllable-hydrothermal method with citric acid as a protective agent

La(OH)3 nanospheres have been synthesized with La(NO3)3 and KOH as the starting materials and citric acid as a protective agent through a facile controllable hydrothermal method. The obtained products were analysed with x-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The formation mechanism of the La(OH)3 nanospheres was investigated in detail.

Novel dandelion-like beta-manganese dioxide microstructures and their magnetic properties.

Single-crystalline dandelion-like β-MnO(2) three-dimensional microstructures have been successfully prepared for the first time via a simple hydrothermal process based on the direct reaction between Mn(NO(3))(2) and H(2)O(2). H(2)O(2) plays an important role in the formation of the dandelion-like morphology. The formation mechanism of the dandelion-like nanostructures was investigated and discussed based on the experimental results. Magnetic measurements show that the Néel temperature of the as-obtained product is 100xa0K, which is about 6xa0K higher than that of the corresponding bulk β-MnO(2) crystals.

A surfactant-free route to single-crystalline CeO2 nanowires

A surfactant-free route was successfully established to synthesize CeO2 single-crystalline nanowires using H2O2 as oxidizer and template agent.

Highly Water-soluble [60]Fullerene-ethylenediamino-β-cyclodextrin Inclusion Complex: The Synthesis and Self-assembly with Poly (Acrylic Acid)

A highly water-soluble [60]fullerene inclusion complex bicapped with ethylenediamino-β-cyclodextrin was prepared, which was further used to construct uniform cubical microstructure with poly (acrylic acid). The formation of the inclusion complex was confirmed by NMR studies. The analysis of X-ray photoelectron spectroscopy and thermogravimetric analysis data revealed that the fullerene molecule was bicapped with β-cyclodextrin. The self-assembly of [60]fullerene inclusion complex with poly (acrylic acid) was investigated by UV-Vis spectroscopic titrations, supporting a 1:1 monomeric units binding model and yielding a complex stability constant of 9.8 × 103 M− 1. The cubical microstructure formed was proved to be a crystalline structure by transmission electron spectroscopy measurements.