Dr Helen (Xiaoxue) Xu is a Chancellor’s Postdoctoral Research Fellow (2017.06-2021.06) at the University of Technology Sydney in the Institute for Biomedical Materials & Devices. Her research focuses on inorganic biomedical nanomaterials for applications in biomedical implants, biomedical imaging diagnosis and nanomedicine therapy. Her most recent research program is the development of luminescent upconversion nanomaterials for precision theranostics.
Prior to joining UTS, Dr Xu completed a Macquarie University Research Fellowship (2015-2017) on the hybrid nanomaterials based on the upconversion nanomaterials for cell labelling and imaging.
Dr Xu used to hold a Research Assistant Professor position at University of Western Australia conducting research on 3D printing of titanium alloy to bone scaffold with Prof Tim Sercombe as well as metal oxide nanostructures for cosmetic applications wth Prof Paul McCormick. She completed her PhD in Materials and Chemical Engineering with Prof Hong Yang and Prof Yinong Liu at the University of Western Australia in September 2012.
Dr Xu received her Master’s Degree in Biomedical metallic materials for biomedical implants of stents and intrauterine devices from Harbin Engineering University in 2006 with one year research experience in Peking University with Prof Yufeng Zheng. She also was awarded her Bachelor’s degree of science on materials Physics from Harbin Engineering University in 2003.
Dr Helen Xu serves as regular reviewers for Reviewer for Nanoscale, Mater Design, Mater Lett, Mater Sci Eng C, Polymers, J Cell Mol Med, and Nanomaterials. She is the guest editor for Frontiers in Materials and Reviewer Board Member for Polymers (MDPI).
Dr Helen Xu is the member of a variety of societies, including Australian Nanotechnology Network (ANN), Australin Centre for Microscopy & Microanalysis (ACMM), Royal Australian Chemical Institute (RACI), Sydney Vital, Franklin Women, Frontiers Technology Clinical Academic Group and Academic Women in Science (AWiS) at UTS.
Dr Helen Xu is actively involved in academic and professional development activities as organising committee and Honorary Positions, including
- Leading organizer, Early Career Women in STEMM Paper & Grant Writing Workshop (ECWW) (UTS, 16th-18th, September 2020).
- Co-organizer, 1st International Conference on Sustainable Sensing System (UNSW, 1st-3rd, Nov 2020)
- ECWR (ANU, 2019), funding raising (total AU$8000), event organizing and mentor inviting;
- Honorary Lecturer at Macquarie University (2018-2021)
-Associated Investigator: ARC Centre of Excellence in Nanoscale BioPhysics at Macquarie Node (2015-2021).
Can supervise: YES
1, Luminescent nanomaterials Structure Control for multimodal imaging contrast agent
2, Luminescent nanomaterials Surface Chemistry for multiplexing bio-sensing of ctDNA
3, Luminescent nanomaterials Surface Engineering for drug delivery towards chemotherapy in breast cancers
Introduction to Materials
Materials Science and Chemistry
Medical Imaging Technology
Deng, ZX, Tao, JW, Zhang, W, Mu, HJ, Wu, HJ, Wang, YB, Xu, XX & Zheng, W 2021, 'Effect of protein adsorption on electrospun hemoglobin/gelatin-MWCNTs microbelts modified electrode: Toward electrochemical measurement of hydrogen peroxide', Materials Chemistry and Physics, vol. 257.View/Download from: Publisher's site
© 2020 Elsevier B.V. The on-line electrochemical analysis is one of powerful strategies in analytical chemistry and pathophysiology. To achieve high sensitivity and long-term stability of electrochemical biosensor, the bottleneck challenge is the spontaneous proteins adsorption onto the electrode surface within the biological fluids or in vivo environments. In this work, a hemoglobin/gelatin-multiwalled carbon nanotubes microbelts modified electrode (Hb/gelatin-MWCNTs/GC electrode) was successfully fabricated via one-step electrospinning process. The results of atomic force microscopy (AFM), scanning electron microscopy (SEM) and water contact angle test confirmed the electrospun Hb/gelatin-MWCNTs microbelts possessed smooth and hydrophilic surfaces. Furthermore, the electrospun Hb/gelatin-MWCNTs/GC electrode after protein adsorption displayed an excellent electrocatalytic sensitivity toward the reduction of hydrogen peroxide (H2O2). Moreover, the Hb/gelatin-MWCNTs/GC electrode presented very high biological affinity to H2O2 (Kmapp=503.4 ± 2.8 μmol L−1) after 360 min protein adsorption compared to that of the electrode before protein adsorption (Kmapp=298.1 ± 3.1 μmol L−1). The microbelts constructed H2O2 biosensor showed high selectivity, stability and reproducibility after protein adsorption. Therefore, this work provided the proof of the concept that the electrospun Hb/gelatin-MWCNTs/GC electrode displayed excellent sensing performance to H2O2 after protein adsorption, which could enable the implantable electrochemical biosensor for the on-line analysis.
Deng, ZX, Tao, JW, Zhao, LJ, Zhang, W, Wang, YB, Mu, HJ, Wu, HJ, Xu, XX & Zheng, W 2020, 'Effect of protein adsorption on bioelectrochemistry of electrospun core-shell MWCNTs/gelatin-Hb nanobelts on electrode surface', Process Biochemistry, vol. 96, pp. 73-79.View/Download from: Publisher's site
© 2020 Elsevier Ltd Implantable electrochemical biosensor is one powerful tool for the accurate and reliable measurements of small molecules in vivo. However, the electrode is inevitably subjected to the protein adsorption when implanted into the living animals, affecting the sensitivity and stability of biosensor. Herein, we designed the multi-walled carbon nanotubes/gelatin-hemoglobin (MWCNTs/gelatin-Hb) core-shell nanobelts constructed on glassy carbon electrode (GC) using the one-step electrospinning technique for studying the effect of protein adsorption on the electrode surface properties. The results of the water contact angle and the scanning electron microscopy (SEM) showed that the electrospun core-shell MWCNTs/gelatin-Hb nanobelts present hydrophilic and certain anti-protein adsorption properties. Direct electron transfer between the Hb molecules in the electrospun core-shell nanobelts and electrode and catalysis of hydrogen peroxide (H2O2) can be still achieved after the electrospun core-shell MWCNTs/gelatin-Hb nanobelts adsorbed protein. Moreover, compared with before protein adsorption (Kmapp =0.0155 mmol/L), the electrospun core-shell MWCNTs/gelatin-Hb nanobelts after protein adsorption still displayed high biological afﬁnity to H2O2 (Kmapp =0.0382 mmol/L). The constructed H2O2 biosensor by using the electrospun core-shell MWCNTs/gelatin-Hb nanobelts showed high sensitivity, great reproducibility and stability after protein adsorption. This study provides a novel design and an effective platform for the development of implantable electrochemical biosensors.
Du, Z, Gupta, A, Clarke, C, Cappadona, M, Clases, D, Liu, D, Yang, Z, Karan, S, Price, W & Xu, X 2020, 'Porous Upconversion Nanostructures as Bimodal Biomedical Imaging Contrast Agents', JOURNAL OF PHYSICAL CHEMISTRY C, vol. 124, no. 22, pp. 12168-12174.View/Download from: Publisher's site
Gao, L, Shan, X, Xu, X, Liu, Y, Liu, B, Li, S, Wen, S, Ma, C, Jin, D & Wang, F 2020, 'Correction: Video-rate upconversion display from optimized lanthanide ion doped upconversion nanoparticles.', Nanoscale, vol. 12, no. 36, p. 18987.View/Download from: Publisher's site
Correction for 'Video-rate upconversion display from optimized lanthanide ion doped upconversion nanoparticles' by Laixu Gao et al., Nanoscale, 2020, DOI: .
Gao, L, Shan, X, Xu, X, Liu, Y, Liu, B, Li, S, Wen, S, Ma, C, Jin, D & Wang, F 2020, 'Video-rate upconversion display from optimized lanthanide ion doped upconversion nanoparticles', Nanoscale.View/Download from: Publisher's site
Volumetric displays that create bright image points within a transparent bulk are one of the most attractive technologies in everyday life. Lanthanide ion doped upconversion nanoparticles (UCNPs) are promising luminescent nanomaterials for background free, full-colour volumetric displays of transparent bulk materials. However, video-rate display using UCNPs has been limited by their low emission intensity. Herein, we developed a video-rate upconversion display system with much enhanced brightness. The integral emission intensity of the single UCNPs was fully employed for video-rate display. It was maximized by optimizing the emitter concentration and, more importantly, by temporally synchronizing the scanning time of the excitation light to the the raised emission time of the single UCNPs. The excitation power dependent emission response and emission time decay curves were systematically characterized for the single UCNPs with various emitter concentrations from 0.5% to 6%. 1%Tm3+ doped UCNPs presented the highest integral emission intensity. By embedding this UCNPs into a polyvinyl acetate (PVA) film, we achieved a two-dimensional (2D) upconversion display with a frame rate of 29 Hz for 35 by 50 pixels. This work demonstrates that the temporal response as well as the integral emission intensity enable video-rate upconversion display.
Liu, Y, Wang, F, Lu, H, Fang, G, Wen, S, Chen, C, Shan, X, Xu, X, Zhang, L, Stenzel, M & Jin, D 2020, 'Super-Resolution Mapping of Single Nanoparticles inside Tumor Spheroids', SMALL, vol. 16, no. 6.View/Download from: Publisher's site
© Copyright © 2020 Xu, Lu and Lee. Nanomaterials-based phototherapies, mainly including photothermal therapy (PTT), photodynamic therapy (PDT) and photoimmunotherapy (PIT), present high efficacy, minimal invasion and negligible adverse effects in cancer treatment. The integrated phototherapeutic modalities can enhance the efficiency of cancer immunotherapy for clinical application transformation. The near-infrared (NIR) light source enables phototherapies with the high penetration depth in the biological tissues, less toxic to normal cells and tissues and a low dose of light irradiation. Mediated via the novel NIR-responsive nanomaterials, PTT and PDT are able to provoke cancer cells apoptosis from the generated heat and reactive oxygen species, respectively. The released cancer-specific antigens and membrane damage danger signals from the damaged cancer cells trigger immune responses, which would enhance the antitumor efficacy via a variety of immunotherapy. This review summarized the recent advances in NIR-triggered photo-/immune-therapeutic modalities and their synergistic mechanisms and applications toward cancers. Furthermore, the challenges, potential solutions and future directions of NIR-triggered photo-/immunotherapy were briefly discussed.
Froch, JE, Kim, S, Stewart, C, Xu, X, Du, Z, Lockrey, M, Toth, M & Aharonovich, I 2020, 'Photonic Nanobeam Cavities with Nanopockets for Efficient Integration of Fluorescent Nanoparticles', NANO LETTERS, vol. 20, no. 4, pp. 2784-2790.View/Download from: Publisher's site
Xu, X, Zhou, Z, Liu, Y, Wen, S, Guo, Z, Gao, L & Wang, F 2019, 'Optimising passivation shell thickness of single upconversion nanoparticles using a time-resolved spectrometer', APL Photonics, vol. 4, no. 2.View/Download from: Publisher's site
© 2019 Author(s). Lanthanide-doped upconversion nanoparticles (UCNPs) are the most efficient multi-photon probe that can be used for deep tissue bio-imaging, fluorescence microscopy, and single molecule sensing applications. Passivating UCNPs with inert shell has been demonstrated to be an effective method to significantly enhance their brightness. However, this method also increases the overall size of the nanoparticles, which limited their cellular applications. Current reports to optimise the thickness of the shell are based on the spectrum measurement of ensembles of UCNPs, which are less quantitative. The characterisation of single UCNPs would be desirable, but is limited by the sensitivity of conventional spectrometers. We developed an optical filter-based spectrometer coupled to a laser scanning microscopy system and achieved a high degree of sensitivity - seven times more than the traditional amount. Through highly controlled syntheses of a range Yb 3+ and Tm 3+ doped UCNPs with different shell thickness, quantitative characterization of the emission intensity and lifetime on single UCNPs were comprehensively studied using a home-made optical system. We found that the optimal shell thickness was 6.3 nm. We further demonstrated that the system was sensitive enough to measure the time-resolved spectrum from a single UCNP, which is significantly useful for a comprehensive study of the energy transfer process of UCNPs.
Zhang, X, Xiang, X, Wang, Y, Ding, G, Xu, X & Yang, Z 2019, 'A Heterogeneous Integrated MEMS Inertial Switch With Compliant Cantilevers Fixed Electrode and Electrostatic Locking to Realize Stable On-State', Journal of Microelectromechanical Systems, vol. 28, no. 6, pp. 977-986.View/Download from: Publisher's site
Clarke, C, Liu, D, Wang, F, Liu, Y, Chen, C, Ton-That, C, Xu, X & Jin, D 2018, 'Large-scale dewetting assembly of gold nanoparticles for plasmonic enhanced upconversion nanoparticles.', Nanoscale, vol. 10, no. 14, pp. 6270-6276.View/Download from: Publisher's site
Plasmonic nanostructures have been broadly investigated for enhancing many photophysical properties of luminescent nanomaterials. Precisely controlling the distance between the plasmonic nanostructure and the luminescent material is challenging particularly for the large-scale production of individual nanoparticles. Here we report an easy and reliable method for the large-scale dewetting of plasmonic gold nanoparticles onto core-shell (CS) upconversion nanoparticles (UCNPs). A commensurate NaYF4 shell with a thickness between 5 nm and 15 nm is used as a tunable spacer to control the distance between the UCNP and the plasmonic gold nanoparticles. The upconversion emission intensity of single gold decorated core-inert shell (Au-CS) UCNPs is quantitatively characterized using a scanning confocal microscope. The results demonstrate the highest feasible enhancement of upconversion emission and a record reduction in lifetime for UCNPs fabricated in this manner. The Au-CS UCNPs are further investigated by simulation and synchrotron near edge X-ray absorption fine structure (NEXAFS) analysis.
Sun, Y, Zhang, W, Wang, B, Xu, X, Chou, J, Shimoni, O, Ung, AT & Jin, D 2018, 'A supramolecular self-assembly strategy for upconversion nanoparticle bioconjugation.', Chemical communications (Cambridge, England), vol. 54, no. 31, pp. 3851-3854.View/Download from: Publisher's site
An efficient surface modification for upconversion nanoparticles (UCNPs) is reported via supramolecular host-guest self-assembly. Cucurbituril (CB) can provide a hydrophilic surface and cavities for most biomolecules. High biological efficiency, activity and versatility of the approach enable UCNPs to be significantly applied in bio-imaging, early disease detection, and bio-sensing.
Ma, C, Xu, X, Wang, F, Zhou, Z, Liu, D, Zhao, J, Guan, M, Lang, CI & Jin, D 2017, 'Optimal Sensitizer Concentration in Single Upconversion Nanocrystals.', Nano Letters, vol. 17, no. 5, pp. 2858-2864.View/Download from: Publisher's site
Each single upconversion nanocrystal (UCNC) usually contains thousands of photon sensitizers and hundreds of photon activators to up-convert near-infrared photons into visible and ultraviolet emissions. Though in principle further increasing the sensitizers' concentration will enhance the absorption efficiency to produce brighter nanocrystals, typically 20% of Yb3+ ions has been used to avoid the so-called "concentration quenching" effect. Here we report that the concentration quenching effect does not limit the sensitizer concentration and NaYbF4 is the most bright host matrix. Surface quenching and the large size of NaYbF4 nanocrystals are the only factors limiting this optimal concentration. Therefore, we further designed sandwich nanostructures of NaYbF4 between a small template core to allow an epitaxial growth of the size-tunable NaYbF4 shell enclosed by an inert shell to minimize surface quenching. As a result, the suspension containing 25.2 nm sandwich structure UCNCs is 1.85 times brighter than the homogeneously doped ones, and the brightness of each single 25.2 nm heterogeneous UCNC is enhanced by nearly 3 times compared to the NaYF4: 20% Yb3+, 4% Tm3+ UCNCs in similar sizes. Particularly, the blue emission intensities of the UCNCs with the sandwich structure in the size of 13.6 and 25.2 nm are 1.36 times and 3.78 times higher than that of the monolithic UCNCs in the similar sizes. Maximizing the sensitizer concentration will accelerate the development of brighter and smaller UCNCs as more efficient biomolecule probes or photon energy converters.
Wang, L, Ren, L, Mitchell, D, Casillas-Garcia, G, Ren, W, Ma, C, Xu, XX, Wen, S, Wang, F, Zhou, J, Xu, X, Hao, W, Dou, SX & Du, Y 2017, 'Enhanced energy transfer in heterogeneous nanocrystals for near infrared upconversion photocurrent generation.', Nanoscale, vol. 9, no. 47, pp. 18661-18667.View/Download from: Publisher's site
The key to produce inorganic heterogeneous nanostructures, and to integrate multiple functionalities, is to enhance or at least retain the functionalities of different components of materials. However, this ideal scenario is often deteriorated at the interface of the heterogeneous nanostructures due to lattice mismatches, resulting in downgraded performance in most hybrid nanomaterials. Here, we report that there is a narrow window in controlling temperature in a Lewis acid-base reaction process to facilitate epitaxial alignment during the synthesis of hybrid nanomaterials. We demonstrate a perfectly fused NaYF4:Yb,Tm@ZnO heterogeneous nanostructure, in which the semiconductor ZnO shell can be epitaxially grown onto lanthanide-doped upconversion nanoparticles. By achieving a matched crystal lattice, the interface defects and crystalline grain boundaries are minimized to enable more efficient energy transfer from the upconversion nanoparticles to the semiconductor, resulting in both enhanced upconversion luminescence intensity and superior photoelectrochemical properties. This strategy provides an outstanding approach to endow lanthanide-doped upconversion nanoparticles with versatile properties.
Xu, X, Clarke, C, Ma, C, Casillas, G, Das, M, Guan, M, Liu, D, Wang, L, Tadich, A, Du, Y, Ton-That, C & Jin, D 2017, 'Depth-profiling of Yb3+ sensitizer ions in NaYF4 upconversion nanoparticles.', Nanoscale, vol. 9, no. 23, pp. 7719-7726.View/Download from: Publisher's site
Enhancing the efficiency of upconversion nanoparticles (UCNPs) and therefore their brightness is the critical goal for this emerging material to meet growing demands in many potential applications including sensing, imaging, solar energy conversion and photonics. The distribution of the photon sensitizer and activator ions that form a network of energy transfer systems within each single UCNP is vital for understanding and optimizing their optical properties. Here we employ synchrotron-based X-ray Photoelectron Spectroscopy (XPS) to characterize the depth distribution of Yb3+ sensitizer ions in host NaYF4 nanoparticles and systematically correlate the structure with the optical properties for a range of UCNPs with different sizes and doping concentrations. We find a radial gradient distribution of Yb3+ from the core to the surface of the NaYF4 nanoparticles, regardless of their size or the sensitizer's concentration. Energy dispersive X-ray Spectroscopy (EDX) was also used to further confirm the distribution of the sensitizer ions in the host matrix. These results have profound implications for the upconversion optical property variations.
Liu, D, Xu, X, Du, Y, Qin, X, Zhang, Y, Ma, C, Wen, S, Ren, W, Goldys, EM, Piper, JA, Dou, S, Liu, X & Jin, D 2016, 'Three-dimensional controlled growth of monodisperse sub-50 nm heterogeneous nanocrystals', Nature Communications, vol. 7, pp. 1-8.View/Download from: Publisher's site
The ultimate frontier in nanomaterials engineering is to realize their composition control with atomic scale precision to enable fabrication of nanoparticles with desirable size, shape and surface properties. Such control becomes even more useful when growing hybrid nanocrystals designed to integrate multiple functionalities. Here we report achieving such degree of control in a family of rare-earth-doped nanomaterials. We experimentally verify the co-existence and different roles of oleate anions (OA−) and molecules (OAH) in the crystal formation. We identify that the control over the ratio of OA− to OAH can be used to directionally inhibit, promote or etch the crystallographic facets of the nanoparticles. This control enables selective grafting of shells with complex morphologies grown over nanocrystal cores, thus allowing the fabrication of a diverse library of monodisperse sub-50 nm nanoparticles. With such programmable additive and subtractive engineering a variety of three-dimensional shapes can be implemented using a bottom–up scalable approach.
Liu, D, Xu, X, Wang, F, Zhou, J, Mi, C, Zhang, L, Lu, Y, Ma, C, Goldys, E, Lin, J & Jin, D 2016, 'Emission stability and reversibility of upconversion nanocrystals', Journal of Materials Chemistry C, vol. 4, no. 39, pp. 9227-9234.View/Download from: Publisher's site
Rare-earth doped upconversion nanocrystals have emerged as a novel class of luminescent probes for biomedical applications. The knowledge about their optical stability in aqueous solution under different pH and temperature conditions has not been comprehensively explored. Here we conduct a systematic investigation and report the emission stability and reversibility of typical NaYF4:Yb3+,Er3+ nanocrystals and their core–shell nanostructures in aqueous solution at different temperatures and with different pH values. These nanocrystals show reversible luminescence response to temperature changes, while low pH permanently quenches their luminescence. With the addition of inert shells, with thicknesses ranging from 1.5 nm to 8 nm, the emission stability and reversibility change significantly. Thicker inert shells not only lead to a significant enhancement in the emission intensity but also stabilize its optical responses which become less affected by temperature variations and pH conditions. This study suggests that upconversion nanocrystal-based sensitive temperature and pH sensors do not generally benefit from the core–shell structure usually recommended for enhanced upconversion luminescence.
Ma, C, Xu, X, Wang, F, Zhou, Z, Wen, S, Liu, D, Fang, J, Lang, CI & Jin, D 2016, 'Probing the Interior Crystal Quality in the Development of More Efficient and Smaller Upconversion Nanoparticles', Journal of Physical Chemistry Letters, vol. 7, pp. 3252-3258.View/Download from: Publisher's site
Optical biomedical imaging using luminescent nanoparticles as contrast agents prefers small size, as they can be used at high dosages and efficiently cleared from body. Reducing nanoparticle size is critical for the stability and specificity for the fluorescence nanoparticles probes for in vitro diagnostics and subcellular imaging. The development of smaller and brighter upconversion nanoparticles (UCNPs) is accordingly a goal for complex imaging in bioenvironments. At present, however, small UCNPs are reported to exhibit less emission intensity due to increased surface deactivation and decreased number of dopants. Here we show that smaller and more efficient UCNPs can be made by improving the interior crystal quality via controlling heating rate during synthesis. We further developed a unique quantitative method for optical characterizations on the single UCNPs with varied sizes and the corresponding shell passivated UCNPs, confirming that the internal crystal quality dominates the relative emission efficiency of the UCNPs.
Yan, L, Zhao, B, Liu, X, Li, X, Zeng, C, Shi, H, Xu, X, Lin, T, Dai, L & Liu, Y 2016, 'Aligned Nanofibers from Polypyrrole/Graphene as Electrodes for Regeneration of Optic Nerve via Electrical Stimulation', ACS Applied Materials and Interfaces, vol. 8, pp. 6834-6840.View/Download from: Publisher's site
Sercombe, TB, Xu, X, Challis, VJ, Green, R, Yue, S, Zhang, Z & Lee, PD 2015, 'Failure modes in high strength and stiffness to weight scaffolds produced by Selective Laser Melting', Materials and Design, vol. 67, pp. 501-508.View/Download from: Publisher's site
Wang, R, Xu, X, Zhang, Y, Chang, Z, Sun, Z & Dong, W-F 2015, 'Functionalized ZnO@TiO2 nanorod array film loaded with ZnIn0.25Cu0.02S1.395 solid-solution: synthesis, characterization and enhanced visible light driven water splitting', Nanoscale, vol. 7, pp. 11082-11092.View/Download from: Publisher's site
Challis, VJ, Xu, X, Zhang, LC, Roberts, AP, Grotowski, JF & Sercombe, TB 2014, 'High specific strength and stiffness structures produced using selective laser melting', Materials and Design, vol. 63, pp. 783-788.View/Download from: Publisher's site
Li, J, Mei, H, Zheng, W, Pan, P, Sun, XJ, Li, F, Guo, F, Zhou, HM, Ma, JY, Xu, XX & Zheng, YF 2014, 'A novel hydrogen peroxide biosensor based on hemoglobin-collagen-CNTs composite nanofibers', COLLOIDS AND SURFACES B-BIOINTERFACES, vol. 118, pp. 77-82.View/Download from: Publisher's site
Li, A, Sun, ZZ, Zhou, M, Xu, XX, Ma, JY, Zheng, W, Zhou, HM, Li, L & Zheng, YF 2013, 'Electrospun Chitosan-graft-PLGA nanofibres with significantly enhanced hydrophilicity and improved mechanical property', Colloids and Surfaces B: Biointerfaces, vol. 102, pp. 674-681.View/Download from: Publisher's site
Xu, XX, Ding, MH, Zhang, JX, Zheng, W, Li, L & Zheng, YF 2013, 'A novel copper/polydimethiylsiloxane nanocomposite for copper-containing intrauterine contraceptive devices', Journal of Biomedical Materials Research Part B: Applied Biomaterials, vol. 101, pp. 1428-1436.View/Download from: Publisher's site
Meng, ZX, Zeng, QT, Sun, ZZ, Xu, XX, Wang, YS, Zheng, W & Zheng, YF 2012, 'Immobilizing natural macromolecule on PLGA electrospun nanofiber with surface entrapment and entrapment-graft techniques', Colloids and Surfaces B: Biointerfaces, vol. 94, pp. 44-50.View/Download from: Publisher's site
Xu, X, Yang, H & Liu, Y 2012, 'Self-assembled structures of CuO primary crystals synthesized from Cu(CH 3COO) 2-NaOH aqueous systems', CrystEngComm, vol. 14, pp. 5289-5298.View/Download from: Publisher's site
Xu, XX, Nie, FL, Wang, YB, Zhang, JX, Zheng, W, Li, L & Zheng, YF 2012, 'Effective inhibition of the early copper ion burst release with ultra-fine grained copper and single crystal copper for intrauterine device application', Acta Biomaterialia, vol. 8, pp. 886-896.View/Download from: Publisher's site
Guo, F, Xu, XX, Sun, ZZ, Zhang, JX, Meng, ZX, Zheng, W, Zhou, HM, Wang, BL & Zheng, YF 2011, 'A novel amperometric hydrogen peroxide biosensor based on electrospun Hb-collagen composite', Colloids and Surfaces B: Biointerfaces, vol. 86, pp. 140-145.View/Download from: Publisher's site
Meng, ZX, Xu, XX, Zheng, W, Zhou, HM, Li, L, Zheng, YF & Lou, X 2011, 'Preparation and characterization of electrospun PLGA/gelatin nanofibers as a potential drug delivery system', Colloids and Surfaces B: Biointerfaces, vol. 84, pp. 97-102.View/Download from: Publisher's site
Xu, X, Yang, H, Liu, Y, Zheng, Y, Li, L, Ji, Y & Han, X 2011, 'Formation mechanism of novel two-dimensional single crystalline dendritic copper plates in an aqueous environment', Acta Materialia, vol. 59, pp. 7177-7188.View/Download from: Publisher's site
Xu, XX, Zhang, JX, Guo, F, Zheng, W, Zhou, HM, Wang, BL, Zheng, YF, Wang, YB, Cheng, Y, Lou, X & Jang, BZ 2011, 'A novel amperometric hydrogen peroxide biosensor based on immobilized Hb in Pluronic P123-nanographene platelets composite', Colloids and Surfaces B: Biointerfaces, vol. 84, pp. 427-432.View/Download from: Publisher's site
Guo, X, Lu, X, Fang, X, Mao, Y, Wang, Z, Chen, L, Xu, X, Yang, H & Liu, Y 2010, 'Lithium storage in hollow spherical ZnFe2O4 as anode materials for lithium ion batteries', Electrochemistry Communications, vol. 12, pp. 847-850.View/Download from: Publisher's site
Xu, XX, Nie, FL, Zhang, JX, Zheng, W, Zheng, YF, Hu, C & Yang, G 2010, 'Corrosion and ion release behavior of ultra-fine grained bulk pure copper fabricated by ECAP in Hanks solution as potential biomaterial for contraception', Materials Letters, vol. 64, pp. 524-527.View/Download from: Publisher's site
Zhao, HY, Xu, XX, Zhang, JX, Zheng, W & Zheng, YF 2010, 'Carbon nanotube-hydroxyapatite-hemoglobin nanocomposites with high bioelectrocatalytic activity', Bioelectrochemistry, vol. 78, pp. 124-129.View/Download from: Publisher's site
Zheng, W, Zhao, HY, Zhang, JX, Zhou, HM, Xu, XX, Zheng, YF, Wang, YB, Cheng, Y & Jang, BZ 2010, 'A glucose/O2 biofuel cell base on nanographene platelet-modified electrodes', Electrochemistry Communications, vol. 12, pp. 869-871.View/Download from: Publisher's site
Zheng, W, Zhao, HY, Zhou, HM, Xu, XX, Ding, MH & Zheng, YF 2010, 'Electrochemistry of bilirubin oxidase at carbon nanotubes', Journal of Solid State Electrochemistry, vol. 14, pp. 249-254.View/Download from: Publisher's site
Sabir, MI, Xu, X & Li, L 2009, 'A review on biodegradable polymeric materials for bone tissue engineering applications', Journal of Materials Science, vol. 44, pp. 5713-5724.View/Download from: Publisher's site
Yang, Z, Ding, G, Cai, H, Xu, X, Wang, H & Zhao, X 2009, 'Analysis and elimination of the 'skip contact' phenomenon in an inertial micro-switch for prolonging its contact time', JOURNAL OF MICROMECHANICS AND MICROENGINEERING, vol. 19, no. 4.View/Download from: Publisher's site
Zhao, HY, Zheng, W, Meng, ZX, Zhou, HM, Xu, XX, Li, Z & Zheng, YF 2009, 'Bioelectrochemistry of hemoglobin immobilized on a sodium alginate-multiwall carbon nanotubes composite film', Biosensors and Bioelectronics, vol. 24, pp. 2352-2357.View/Download from: Publisher's site
Xu, X-X, Li, L & Zheng, Y-F 2008, 'Preparation and surface modification of magnetic nanoparticles for biomedical applications', Cailiao Kexue yu Gongyi/Material Science and Technology, vol. 16, pp. 562-568.
Li, Q-F, Li, L, Liu, E-B, Wang, J, Xu, X-X & Wang, Y-B 2004, 'Study of reverse temper embrittlement NGS mechanism in steel 12CrlMoV', Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University, vol. 25, pp. 451-456.
Zhao, M, Yang, Z, Sun, B, Dai, B, Liu, H, Yao, J, Xu, X, Ding, G & Zhao, X 2019, 'A micro electromagnetically-driven scanner by 2-DOF second-order resonance to extend scanning scale for ultra-thin single-fiber endoscope application', Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), IEEE Micro Electro Mechanical Systems, IEEE, Belfast, UK, pp. 575-578.View/Download from: Publisher's site
© 2018 IEEE. This paper presents an electromagnetically-driven single-fiber scanner utilizing 2 degree-of-freedom (DOF) second-order resonance to realize a larger field scanning scale in narrow space of the human body. We design a reasonable 2-DOF system structure including fiber, magnet and weight, which can conveniently execute high-order resonance modal to extend the scanning angle in the limited dimensional tube of the ultra-thin endoscope. A low-cost flexible microcoil embedded in polyimide film is also fabricated to drive the fiber-magnet-weight 2-DOF system to vibrate. The magnetic field distributions of the microcoil with different structural parameters are simulated. The test result shows that the scanner with the second-order resonance model successfully realizes 9.47° scanning scale, which is much larger than that (2.98°) obtained at the traditional first-order resonance model. Finally, the scanning locus of fiber tip in the scanner probe has been measured in xoy-plane by standard position sensitive detector (PSD).
Wen, S, Li, D, Liu, D, Xu, X, Du, Y, Mitchell, DRG, Shi, B, Shi, X & Jin, D 2016, 'Seed mediated one-pot growth of versatile heterogeneous upconversion nanocrystals for multimodal bioimaging', Proceedings of SPIE - The International Society for Optical Engineering, International Society for Optical Engineering, SPIE Digital Library, Adelaide, South Australia, Australia.View/Download from: Publisher's site
© 2016 SPIE.The rapid development of a variety of molecular contrast agents makes the multimodality bioimaging highly attractive towards higher resolution, more sensitive, informative diagnosis. The key lies in the development of facile material synthesis that allows the integration of multiple contrast agents, ideally in a way that each of the components should be logically assembled to maximize their performances. Here, we report the one-pot programmable growth of multifunctional heterogeneous nanocrystal with tunable size, shape, composition, and properties. We demonstrated a facile one-pot hot-injection method to enable the highly selectively controlled growth of different sodium lanthanide fluoride nanomaterials in either longitudinal or transversal directions with atomic scale precision. This technique allows the upconversion luminescence signal, MRI signal and x-ray signal logically integrated and optimized within one single versatile nanoplatform for multimode bioimaging. These findings suggest that the facile strategy developed here have the promising to get the desired heterogeneous nanocrystals as an all-in-one contrast agent for integrated and self-correlative multimodal bioimaging.
Zheng, W, Ma, JY, Guo, F, Li, J, Zhou, HM, Xu, XX, Li, L & Zheng, YF 2013, 'A novel biofuel cell based on electrospun collagen-carbon nanotube nanofibres', Bio-Medical Materials and Engineering, International Conference on Biomedical Engineering and Biotechnology (iCBEB), IOS Press, Wuhan, China, pp. 229-235.View/Download from: Publisher's site
The paper demonstrates a novel glucose/O2 biofuel cell (BFC) based on the electrospun collagen-SWNTs nanofibres with the glucose oxidase (GOD) as the anodic biocatalysts and the laccase as the cathodic biocatalysts. With an average diameter of about (260±95) nm, the electrospun collagen-SWNTs nanofibres exhibited smooth surfaces. The collagen-SWNTs nanofibres modified electrode showed good electron transfer behavior, because of the properties of SWNTs and the three-dimensional reticular structure of the electrospun nanofibers. The GOD and laccase, immobilized in the collagen-SWNTs nanofibres, exhibited good catalytic activity towards glucose oxidation and oxygen reduction through mediators of ferrocene monocarboxylic acid (FMCA) and 2,2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS), respectively. The maximum power density of the assembled glucose/O2 BFC based on the electrospun collagen-SWNTs nanofibres was ca. 14.3 μW/cm2. Moreover, more than 50% of the initial value remained after continuous operation of 100 h. The results indicated the potential to apply the electrospun collagen-SWNTs nanofibres for novel BFC device.
Xu, XX & Zheng, YF 2006, 'Synthesis and characterization of magnetic nanoparticles and their reinforcement in polyurethane film', Key Engineering Materials, pp. 659-662.
Li, L, Li, Q-F, Guo, E, Liu, E, Cui, X & Xu, X 2005, 'Study on temper embrittlement of phosphorus in steel 12Cr1MoV', Key Engineering Materials, pp. 1183-1188.
Prof Bill Price in MRI at Western Sydney University
Prof Bernie Tuch from Australian Foundation for Diabetes Research
Prof Yufeng Zheng in the bioactive metallic materials from Peking University China
Prof Zhuoqing Yang in biosensing nano/micro systems design and fabrication from Shanghai Jiantong University China
A/Prof Aeju Lee in molecular imaging sensor and multi-drug delivery carrier from Kumamoto University Japan