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•The principle of reactive probes for Hg2+, Cu2+ and Fe3+/Fe2+ detection was reviewed.•The defects of metal probes were analyzed and the possible solutions were given.•The trend of ...development of metal ions probes was discussed.
Transition metal ions were inextricably connected with medicine, life sciences, and environmental science. Some metal ions such as mercury ions, copper ions and iron irons in the environment cannot be degraded and easily enriched at organisms via the obvious biomagnification of food chain, causing a great hazard on human health as well as environment. Therefore, the issue how to monitor the changes and content of metal ions in organisms and environment timely and effectively has become an urgent need for detection techniques. The reaction-based fluorescent probes realize the identification and detection of the analytes through the obvious change of the fluorescence after the chemical reaction between the probes and the target analytes, showing a higher sensitivity and selectivity than those of the traditional chelating probes. This review summarizes the research progress of reaction-based fluorescent probes for the detection of Hg2+, Cu2+and Fe3+/Fe2+ in the past ten years. The detection mechanism of these reaction-typed probes is described in detail, and their application in biological system is explained. The defects of these kinds of metal ion probes emerging at this stage are analyzed and discussed, the possible solutions are given. It can be predicted that the trend of development of metal ion probes in the future is to involve more disciplines with the help of analyzing the mechanism and practical application of a series of reaction-based probes. The close combination of chemistry and biology is needed eagerly to develop the higher-level ones with broad application prospects. At the same time, more in-depth research on the mechanism of metal ions and probes must also be guaranteed. Moreover, through studying and summarizing the identification rules of metal ions, and relying on a set of universal detection mechanisms, it is expected to develop accurately the novel specific and high-performance probes based on reactions for Hg2+, Cu2+and Fe3+/Fe2+ detection.
Carbon-based nanomaterials as important agents for biological applications have emerged in the past few years due to their unique optical, electronic, mechanical, and chemical properties. Many of ...these applications rely on successful surface modifications. This review article comprises two main parts. In the first part, we briefly review the properties and surface modifications of several classes of carbon nanomaterials, mainly carbon nanotubes (CNTs), graphene and its derivatives, carbon dots (CDs) and graphene quantum dots (GQDs), as well as some other forms of carbon-based nanomaterials such as fullerene, carbon nanohorns (CNHs) and carbon nanoonions (CNOs). In the second part, we focus on the biological applications of these carbon nanomaterials, in particular their applications for fluorescence biosensing as well as bioimaging.
Cancer has become one of the greatest causes of death around the world. The treatment of cancer still remains a great problem. With recent advances made in the field of nanotechnology, layered double ...hydroxide (LDH)-based nanosystems have drawn special attention because of their good biocompatibility, pH-dependent biodegradability, anion exchange capacity, easy surface modification and high chemical stability, giving rise to great potential for cancer therapy. In the past decade, LDH-based nanosystems have been constructed for various cancer therapies. However, few review articles have described these important and promising achievements to promote the further development of LDH and its nanocomposites. This review aims to provide a comprehensive overview on the recent developments in LDH and its nanocomposites as powerful nanosystems for diverse cancer therapies, which is divided into five parts: chemotherapy, phototherapy, gene therapy, immunotherapy and combination therapy. This review also outlines future perspectives and current challenges in LDH and its nanocomposites for cancer therapy.
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•The design mechanism and advantages of LDH-based nanosystems are discussed.•Recent advances of LDH-based nanosystems for different cancer therapies are comprehensively overviewed.•Some critical unresolved issues, possible challenges and future perspectives of LDH-based nanosystems are highlighted.
In this work, NiAl-LDH/MnO2 and NiFe-LDH/MnO2 composites are synthesized via a facile hydrothemal method, followed by loading of MnO2 through a redox reaction. MnO2 particles are loaded on the ...surface of LDH nanosheets, leading to the high electrochemical performance of the composites. The as-prepared NiAl-LDH/MnO2-6 exhibits a specific capacitance of 1092 F g−1 at 1 A g−1 and rate retention of 43.2% at 20 A g−1, which are higher than those of pure NiAl-LDH. Meanwhile, an asymmetric supercapacitor (ASC) with NiAl-LDH/MnO2-6 as a positive electrode and activated carbon (AC) as the negative electrode is assembled. It shows high capacitance (87.6 F g−1 at 1 A g−1), rate capability (58.4% at 10 A g−1), high energy density (30.4 Wh Kg−1) and excellent cyclic stability (90.1% after 10000 cycles at 10 A g−1). The other electrode material NiFe-LDH/MnO2-16 exhibits a specific capacitance of 1127 F g−1 at 1 A g−1, and remains 69.8% at 20 A g−1. Meanwhile, NiFe-LDH/MnO2-16//AC ASC also shows high capacitance (81.7 F g−1 at 1 A g−1), rate capability (57.5% at 10 A g−1), energy density (27.3 Wh Kg−1) and excellent cyclic stability (80.5% over 10000 cycles at 10 A g−1). These results indicate that the NiAl-LDH/MnO2 and NiFe-LDH/MnO2 hybrid electrodes could offer great promise in energy storage applications.
•LDH/MnO2 was synthesized via a hydrothemal method, followed by redox reaction.•The synergistic effect between LDH and MnO2 leads to the high electrochemical performance of this nanostructure composites.•The asymmetric supercapacitors exhibited excellent cycle stability.•The asymmetric supercapacitors of this nanostructure composites have been into application.
A novel NiFe-LDH/RGO/CNFs composite was produced by using a facile one-step hydrothermal method as electrode for supercapacitor. Compared with NiFe-LDH/CNFs, NiFe-LDH/CNTs and NiFe-LDH/RGO, ...NiFe-LDH/RGO/CNFs demonstrated a high specific capacitance of 1330.2 F g
at 1 A g
and a super rate capability of 64.2% from 1 to 20 A g
, indicating great potential for supercapacitor application. Additionally, an asymmetric supercapacitor using NiFe-LDH/RGO/CNFs composite as positive electrode material and activated carbon as negative electrode material was assembled. The asymmetric supercapacitor can work in the voltage range of 0-1.57 V. It displayed high energy density of 33.7 W h kg
at power density of 785.8 W kg
and excellent cycling stability with 97.1% of the initial capacitance after 2500 cycles at 8 A g
. Two flexible AC//LDH-RGO-CNFs ASC devices connected in series were able to light up a red LED indicator after being fully charged. The results demonstrate that the AC//LDH-RGO-CNFs ASC has a promising potential in commercial application.
A novel Cobalt Nickle Iron-layered double hydroxide/carbon nanofibres (CoNiFe-LDH/CNFs-0.5) composite was successfully fabricated through an easy in situ growth approach. The morphology and ...composition of the obtained materials were systematically investigated. When the two derived materials were used for supercapacitor electrodes, the CoNiFe-LDH/CNFs-0.5 composite displayed high specific surface area (114.2 m
g
), specific capacitance (1203 F g
at 1 A g
) and rate capability (77.1% from 1 A g
to 10 A g
), which were considerably higher than those of pure CoNiFe-LDH. Moreover, the specific capacitance of CoNiFe-LDH/CNFs-0.5 composite remained at 94.4% after 1000 cycles at 20 A g
, suggesting excellent long-time cycle life. The asymmetric supercapacitor based on CoNiFe-LDH/CNFs-0.5 as a positive electrode and activated carbon as a negative electrode was manufactured and it exhibited a specific capacitance of 84.9 F g
at 1 A g
and a high energy density of 30.2 W h kg
. More importantly, this device showed long-term cycling stability, with 82.7% capacity retention after 2000 cycles at 10 A g
. Thus, this composite with outstanding electrochemical performance could be a promising electrode material for supercapacitors.
Based on modulation of the conjugated polymethine π-electron system of a cyanine dye derivative, a ratiometric near-infared fluorescent probe (Cy7A) for hydrazine (N2H4) has been designed and ...synthesized. Cy7A can be selectively hydrazinolysized with great changes in its fluorescent excitation/emission profiles, which makes it possible to detect N2H4 in water samples and living cells and, for the first time, visualize N2H4 in living mice.
A naphthylamine–rhodamine hybrid ratiometric and colorimetric fluorescent probe (RN) was designed and synthesized. RN can identify Pd2+ ions with high selectivity and sensitivity. Furthermore, the ...probe can be used to monitor Pd2+ ions in live mice by fluorescence imaging.
On the basis of the mechanism of Hg2+-promoted hydrolysis, a new fluorescent chemodosimeter (Rho-Hg1) is reported for single-selective and parts per billion level-sensitive detection of Hg2+ in ...natural waters. Moreover, the fluorescence response of Rho-Hg1 to Hg2+ has little interference from sulfur compounds such as cysteine and glutathione and could be used in the Hg2+ imaging in living cells.
Based on a through bond energy transfer (TBET) between Rhodamine and a naphthalimide fluorophore, a fluorescent ratiometric chemodosimeter RN1 was designed and prepared for single selective detection ...of Cu2+ in aqueous solution and in living cells, as Cu2+ acts as not only a selective recognizing guest but also a hydrolytic promoter.
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