Yujie Xie

A ratiometric fluorescent nanoprobe based on terbium functionalized carbon dots for highly sensitive detection of an anthrax biomarker

A ratiometric fluorescent nanoprobe based on terbium functionalized carbon dots (CDs) was designed to detect dipicolinic acid (DPA) as an anthrax biomarker with high selectivity and sensitivity. CDs were generated by one-step synthesis using an ethylenediaminetetraacetic acid precursor, and served as a scaffold for coordination with Tb(3+) and a fluorescence reference.

A Stimuli-Responsive Smart Lanthanide Nanocomposite for Multidimensional Optical Recording and Encryption

A stimuli-responsive lanthanide-based smart nanocomposite has been fabricated by supramolecular assembly and applied as an active material in multidimensional memory materials. Conjugation of the lanthanide complexes with carbon dots provides a stimuli response that is based on the modulation of the energy level of the ligand and affords microsecond-to-nanosecond fluorescence lifetimes, giving rise to intriguing memory performance in the spatial and temporal dimension. The present study points to a new direction for the future development of multidimensional memory materials based on inorganic-organic hybrid nanosystems.

Gadolinium functionalized carbon dots for fluorescence/magnetic resonance dual-modality imaging of mesenchymal stem cells

The development of multimodal nanoprobes is of great importance in nanomedicine because it integrates the advantages of each imaging modality and offers a significantly enhanced diagnostic effect. In this work, gadolinium(iii) functionalized fluorescent carbon dots (Gd-CDs) are synthesized by means of a one-step hydrothermal approach. As a fluorescent nanomaterial, the obtained Gd-CDs exhibit strong and stable fluorescence with excitation-independent emission behavior. Moreover, as an MRI contrast agent, the Gd-CDs exhibited a longitudinal relaxation rate of 6.06 mM-1 s-1, which is significantly higher than that of the commercially available MRI agent Gadovist (4.24 mM-1 s-1). In addition, the cellular experiment reveals that Gd-CDs promote the proliferation of human mesenchymal stem cells (hMSCs), which is tracked by the fluorescence/Magnetic Resonance dual-modality imaging of hMSCs by the Gd-CDs.

An Elaborate Supramolecular Assembly for a Smart Nanodevice for Ratiometric Molecular Recognition and Logic Gates.

Ingenious approaches to supramolecular assembly for fabricating smart nanodevices is one of the more significant topics in nanomaterials research. Herein, by using surface quaternized cationic carbon dots (CDots) as the assembly and fluorescence platform, anionic sulfonatocalix[4]arene with modifiable lower and upper rims as a connector, as well as in situ coordination of Tb(3+) ions, we propose an elaborate supramolecular assembly strategy for the facile fabrication of a multifunctional nanodevice. The dynamic equilibrium characteristics of the supramolecular interaction can eventually endow this nanodevice with functions of fluorescent ratiometric molecular recognition and as a nano-logic gate with two output channels.

A paper-based lanthanide smart device for acid–base vapour detection, anti-counterfeiting and logic operations

Paper-based devices have attracted extensive attention due to their portability, low-cost, ubiquity, low environmental footprint and ease of operation. In the present study, two lanthanide complexes, namely [Eu(PBA)3(H2O)2] (Eu-PBA) and [Tb(HPBA)2(NO3)3] (Tb-HPBA) were synthesized using an amide-type β-diketone building block, N-(2-pyridinyl)benzoylacetamide (HPBA), which is capable of changing its energy-level to match that of Tb3+ and Eu3+ ions in an acid–base environment. This feature was used for the design and assembly of a simple and cost-effective paper-based lanthanide smart device (abbreviated as Paper-Eu/Tb), which was obtained by impregnating the filter paper with both the Eu-PBA and Tb-HPBA complexes; related homometallic Paper-Eu and Paper-Tb materials were also generated and characterized for comparative purposes. The obtained Paper-Eu/Tb device shows excellent luminescence properties, thus allowing its efficient use as a smart sensor for the naked-eye detection of various acid–base vapours with quick response, good reversibility and selectivity. A similar concept and the resulting paper-based device was also successfully expanded for other applications that include anti-counterfeiting and logic gate systems. Full characterization of the paper-based materials and examples of their use are described. Introduction to the international collaboration The present article is a part of an ongoing collaboration between the College of Chemistry and Chemical Engineering of Lanzhou University (P.R. China) and Instituto Superior Tecnico of University of Lisbon (Portugal). Starting from 2013, this collaboration has been successful in merging the expertise of the Chinese group on novel rare-earth complexes and their smart devices for luminescent probes, tumor marker/treatment, optical anti-counterfeiting, and catalysis with that of the Portuguese group on coordination chemistry, crystal engineering, and catalysis. This Sino-European collaboration has already resulted in the publication of 10 research papers devoted to the design and assembly of various smart nanocomposite materials for applications ranging from cancer therapy and detection of biomarkers to oxidation catalysis and sensing or separation of metal ions.

Multiplex recognition and logic devices for molecular robot prototype based on an europium(iii)–cyclen system

Molecular robot provides a promising way to receive response signals and make decisions with intelligent information processing at the molecule level. In this work, a molecular robot prototype based on a europium(III)-cyclen complex (EuL) was designed and assembled, consisting of multiplex sensing and information processing in a single system. By utilizing the Eu3+ ion as a central processing unit (CPU) and terpyridine (Terpy) group as an arm of the molecular robot, multiplex detection function of this molecular robot can be accomplished in three test channels: the detection of Fe2+ with UV-vis, Zn2+ using photoluminescence, and Mn2+ using magnetic resonance imaging. The optimized structures revealed that the transition metal ions bound by the arms of two EuL molecules formed a hexacoordination octahedral rigidity structure in the adducts. For the structure of L and EuL, three pyridine rings of Terpy unit were not in a plane, and they were fixed to form a plane when captured the transition metal ions during the formation of the adducts. In addition, three different modes of molecular logic devices (OR, INHIBIT, and YES) were established based on relevant signals in the multiplex detection channels. The sensing of metal ions in human urine using EuL was also carried out, and the result demonstrated the presence of good recoveries and high analytical precision. Such a molecular robot prototype is expected to be used in intelligent medical diagnostics and, in particular, information processing at molecular level.