Supermedia User Interface for Scanning Probe Microscopy

当利用扫描隧道显微镜(SPM)作为一种纳米操作工具时,由于其缺乏实时的传感器信息反馈,而大大阻碍了它的广泛应用.利用超媒体人机交互接口可以解决这个问题.在纳米操作过程中,超媒体接口不但可以为操作者提供可实时更新的仿真操作场景,还可以通过力反馈手柄让操作者实时地感受到探针受到的三维纳米操作力.除此之外,操作者还可以通过该手柄直接控制探针的三维运动.最后在聚碳酸酯上进行了超媒体人机接口的纳米刻画实验.实验结果验证了该系统的有效性和效率.

Xenon probe for detecting the microporous structure of nanosized HZSM-5 zeolite

The secondary pores in the nanosized HZSM-5 zeolite have been observed for the first time via Xe-129 NMR spectroscopy using xenon as a probe; the location of non-framework Al can also be identified.

A new europium chelate-based phosphorescence probe specific for singlet oxygen

The first Eu3+ chelate-based phosphorescence probe specific for singlet oxygen has been designed, synthesized and characterized. The probe is highly sensitive, selective and water soluble for time-resolved luminescence detection of singlet oxygen with a detection limit of 2.8 nM.

Synchrotron-laser pump-probe luminescence spectroscopy: Correlation of electronic defect states with x-ray absorption in wide-gap solids

Poolton, Nigel; Hamilton, B.; Evans, D.A., (2005) 'Synchrotron-laser pump-probe luminescence spectroscopy: Correlation of electronic defect states with x-ray absorption in wide-gap solids', Journal of Physics D: Applied Physics 38 pp.1478-1484 RAE2008

Nanoscale electronic properties of conjugated polymers and nanocrystals

The objective of this thesis is the exploration and characterisation of the nanoscale electronic properties of conjugated polymers and nanocrystals. In Chapter 2, the first application of conducting-probe atomic force microscopy (CP-AFM)-based displacement-voltage (z-V) spectroscopy to local measurement of electronic properties of conjugated polymer thin films is reported. Charge injection thresholds along with corresponding single particle gap and exciton binding energies are determined for a poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] thin film. By performing measurements across a grid of locations on the film, a series of exciton binding energy distributions are identified. The variation in measured exciton binding energies is in contrast to the smoothness of the film suggesting that the variation may be attributable to differences in the nano-environment of the polymer molecules within the film at each measurement location. In Chapter 3, the CP-AFM-based z-V spectroscopy method is extended for the first time to local, room temperature measurements of the Coulomb blockade voltage thresholds arising from sequential single electron charging of 28 kDa Au nanocrystal arrays. The fluid-like properties of the nanocrystal arrays enable reproducible formation of nanoscale probe-array-substrate junctions, allowing the influence of background charge on the electronic properties of the array to be identified. CP-AFM also allows complementary topography and phase data to be acquired before and after spectroscopy measurements, enabling comparison of local array morphology with local measurements of the Coulomb blockade thresholds. In Chapter 4, melt-assisted template wetting is applied for the first time to massively parallel fabrication of poly-(3-hexylthiophene) nanowires. The structural characteristics of the wires are first presented. Two-terminal electrical measurements of individual nanowires, utilising a CP-AFM tip as the source electrode, are then used to obtain the intrinsic nanowire resistivity and the total nanowire-electrode contact resistance subsequently allowing single nanowire hole mobility and mean nanowire-electrode barrier height values to be estimated. In Chapter 5, solution-assisted template wetting is used for fabrication of fluorene-dithiophene co-polymer nanowires. The structural characteristics of these wires are also presented. Two-terminal electrical measurements of individual nanowires indicate barrier formation at the nanowire-electrode interfaces and measured resistivity values suggest doping of the nanowires, possibly due to air exposure. The first report of single conjugated polymer nanowires as ultra-miniature photodetectors is presented, with single wire devices yielding external quantum efficiencies ~ 0.1 % and responsivities ~ 0.4 mA/W under monochromatic illumination.

A Plasmonic Gold Nanostar Theranostic Probe for In Vivo Tumor Imaging and Photothermal Therapy.

Nanomedicine has attracted increasing attention in recent years, because it offers great promise to provide personalized diagnostics and therapy with improved treatment efficacy and specificity. In this study, we developed a gold nanostar (GNS) probe for multi-modality theranostics including surface-enhanced Raman scattering (SERS) detection, x-ray computed tomography (CT), two-photon luminescence (TPL) imaging, and photothermal therapy (PTT). We performed radiolabeling, as well as CT and optical imaging, to investigate the GNS probe's biodistribution and intratumoral uptake at both macroscopic and microscopic scales. We also characterized the performance of the GNS nanoprobe for in vitro photothermal heating and in vivo photothermal ablation of primary sarcomas in mice. The results showed that 30-nm GNS have higher tumor uptake, as well as deeper penetration into tumor interstitial space compared to 60-nm GNS. In addition, we found that a higher injection dose of GNS can increase the percentage of tumor uptake. We also demonstrated the GNS probe's superior photothermal conversion efficiency with a highly concentrated heating effect due to a tip-enhanced plasmonic effect. In vivo photothermal therapy with a near-infrared (NIR) laser under the maximum permissible exposure (MPE) led to ablation of aggressive tumors containing GNS, but had no effect in the absence of GNS. This multifunctional GNS probe has the potential to be used for in vivo biosensing, preoperative CT imaging, intraoperative detection with optical methods (SERS and TPL), as well as image-guided photothermal therapy.