Showing papers by "Zhuang Liu published in 2012"
TL;DR: In this critical review, recent reports regarding the synthesis of water-soluble UCNPs and their surface modification and bioconjugation chemistry are summarized and the applications ofUCNPs for small-animal imaging, including tumor-targeted imaging, lymphatic imaging, vascular imaging and cell tracking are reviewed in detail.
Abstract: Rare-earth upconversion nanophosphors (UCNPs), when excited by continuous-wave near-infrared light, exhibit a unique narrow photoluminescence with higher energy. Such special upconversion luminescence makes UCNPs promising as bioimaging probes with attractive features, such as no auto-fluorescence from biological samples and a large penetration depth. As a result, UCNPs have emerged as novel imaging agents for small animals. In this critical review, recent reports regarding the synthesis of water-soluble UCNPs and their surface modification and bioconjugation chemistry are summarized. The applications of UCNPs for small-animal imaging, including tumor-targeted imaging, lymphatic imaging, vascular imaging and cell tracking are reviewed in detail. The exploration of UCNPs as multifunctional nanoscale carriers for integrated imaging and therapy is also presented. The biodistribution and toxicology of UCNPs are further described. Finally, we discuss the challenges and opportunities in the development of UCNP-based nanoplatforms for small-animal imaging (276 references).
1,442 citations
TL;DR: Using this theranostic nanoprobe, in-vivo triple modal fluorescence, photoacoustic, and magnetic resonance imaging are carried out, uncovering high passive tumor targeting, which is further used for effective photothermal ablation of tumors in mice.
Abstract: In this work, a nanoscale reduced graphene oxide-iron oxide nanoparticle (RGO-IONP) complex is noncovalently functionalized with polyethylene glycol (PEG), obtaining a RGO-IONP-PEG nanocomposite with excellent physiological stability, strong NIR optical absorbance, and superparamagnetic properties. Using this theranostic nanoprobe, in-vivo triple modal fluorescence, photoacoustic, and magnetic resonance imaging are carried out, uncovering high passive tumor targeting, which is further used for effective photothermal ablation of tumors in mice.
858 citations
TL;DR: A novel high excited state energy transfer pathway to overcome the phonon quenching effect in rare-earth (RE) oxide upconversion materials is reported.
Abstract: A novel high excited state energy transfer pathway to overcome the phonon quenching effect in rare-earth (RE) oxide upconversion (UC) materials is reported. In Er(Tm)-Yb oxide systems, an extraordinary enhancement of UC luminescence efficiency with four orders of magnitude is realized by Mo co-doping. The RE oxides with significant UC efficiency are successfully utilized for temperature sensing and in vivo imaging.
706 citations
TL;DR: The results highlight that both surface chemistry and sizes are critical to the in vivo performance of graphene, and show the promise of using optimized nano-graphene for ultra-effective photothermal treatment, which may potentially be combined with other therapeutic approaches to assist the fight against cancer.
674 citations
TL;DR: The majority of currently used PTT agents are inorganic nanomaterials, which usually are not biodegradable and may remain inside the body for long periods of time after systemic administration, but the use of organic nanoparticles, such as porphysome and light-absorbing conductive polymers, as PTT agent has thus attracted attention recently.
Abstract: Kai Yang , Huan Xu , Liang Cheng , Chunyang Sun , Jun Wang , and Zhuang Liu * IO N Photothermal therapy (PTT) that uses optical absorbing agents to “cook” cancer under light irradiation has attracted signifi cant attention in recent years as a promising alternative or supplement to traditional cancer therapies. [ 1–3 ] Numerous reports have shown encouraging therapeutic effects of PTT in many preclinical animal experiments, using various light absorbing nanomaterials as PTT agents. [ 1–21 ] Ideal PTT agents should exhibit strong absorbance in the near-infrared (NIR) region, which is a transparency window for biological tissues, and could effi ciently transfer the absorbed NIR optical energy into heat. The biocompatibility of PTT agents is another primary concern. The tumor-homing ability of PTT agents is also important for photothermal treatment of cancer upon systemic administration. Gold nanomaterials including nanorods, nanocages, nanoshells, and composite nanostructures are likely the mostwidely explored class of PTT nanoagents. [ 4–8 , 19 , 20 ] A number of other inorganic nanomaterials, such as carbon nanomaterials [ 9–13 , 17 , 18 , 21 ] (e.g., carbon nanotubes, nanographene), Pd nanosheets, copper sulfi de and copper selenide nanoparticles, have also shown potential in PTT cancer treatment. [ 14–16 ] However, the majority of currently used PTT agents are inorganic nanomaterials, which usually are not biodegradable and may remain inside the body for long periods of time after systemic administration. The use of organic nanoparticles, such as porphysome and light-absorbing conductive polymers, as PTT agents, has thus attracted signifi cant attention recently. [ 22–24 ]
674 citations
TL;DR: This work provides a facile method to synthesize Cdots as safe non-heavy-metal-containing fluorescent nanoprobes, promising for applications in biomedical imaging.
Abstract: Oxidization of carbon nanotubes by a mixed acid has been utilized as a standard method to functionalize carbon nanomaterials for years. Here, the products obtained from carbon nanotubes and graphite after a mixed-acid treatment are carefully studied. Nearly identical carbon dot (Cdot) products with diameters of 3-4 nm are produced using this approach from a variety of carbon starting materials, including single-walled carbon nanotubes, multiwalled carbon nanotubes, and graphite. These Cdots exhibit strong yellow fluorescence under UV irradiation and shifted emission peaks as the excitation wavelength is changed. In vivo fluorescence imaging with Cdots is then demonstrated in mouse experiments, by using varied excitation wavelengths including some in the near-infrared (NIR) region. Furthermore, in vivo biodistribution and toxicology of those Cdots in mice over different periods of time are studied; no noticeable signs of toxicity for Cdots to the treated animals are discovered. This work provides a facile method to synthesize Cdots as safe non-heavy-metal-containing fluorescent nanoprobes, promising for applications in biomedical imaging.
594 citations
TL;DR: This work synthesizes a multi-functional superparamagnetic graphene oxide-iron oxide hybrid nanocomposite (GO-IONP), which is then functionalized by a biocompatible polyethylene glycol (PEG) polymer to acquire high stability in physiological solutions.
Abstract: Two-dimensional graphene and its composite nanomaterials offer interesting physical/chemical properties and have been extensively explored in a wide range of fields in recent years. In this work, we synthesize a multi-functional superparamagnetic graphene oxide-iron oxide hybrid nanocomposite (GO-IONP), which is then functionalized by a biocompatible polyethylene glycol (PEG) polymer to acquire high stability in physiological solutions. A chemotherapy drug, doxorubicin (DOX), was loaded onto GO-IONP-PEG, forming a GO-IONP-PEG-DOX complex, which enables magnetically targeted drug delivery. GO-IONP-PEG also exhibits strong optical absorbance from the visible to the near-infrared (NIR) region, and can be utilized for localized photothermal ablation of cancer cells guided by the magnetic field. Moreover, for the first time, in vivo magnetic resonance (MR) imaging of tumor-bearing mice is also demonstrated using GO-IONP-PEG as the T2 contrast agent. Our work suggests the promise of using multifunctional GO-based nanocomposites for applications in cancer theranostics. Open image in new window
542 citations
TL;DR: Although all of these attempts were successful in principle, there were significant limitations associated with the use of high-intensity UV or visible light in the photo-activation process.
Abstract: Although all of these attempts were successfulin principle, there were significant limitations associated withthe use of high-intensity UV or visible light in the photo-activation process. Excessive exposure to UV light can causephotoreactions in nucleic acids and result in cellular damage.Furthermore, short-wavelength UV or visible light does notpenetrate into tissue very far, which limits its utility for deep-tissue imaging by photoactivation of the caged compounds.Alternatively, multiphoton photolysis with long-wavelengthexcitation has been used to enable deep-tissue imaging and totarget gene expression
428 citations
TL;DR: This work presents a facile approach to synthesize water-soluble noble metal coated SWNTs with a strong SERS effect suitable for labeling and fast Raman spectroscopic imaging of biological samples, which has been rarely realized before.
Abstract: Single-walled carbon nanotubes (SWNTs) with various unique optical properties are interesting nanoprobes widely explored in biomedical imaging and phototherapies. Herein, DNA-functionalized SWNTs are modified with noble metal (Ag or Au) nanoparticles via an in situ solution phase synthesis method comprised of seed attachment, seeded growth, and surface modification with polyethylene glycol (PEG), yielding SWNT-Ag-PEG and SWNT-Au-PEG nanocomposites stable in physiological environments. With gold or silver nanoparticles decorated on the surface, the SWNT-metal nanocomposites gain an excellent concentration and excitation-source dependent surface-enhanced Raman scattering (SERS) effect. Using a near-infrared (NIR) laser as the excitation source, targeted Raman imaging of cancer cells labeled with folic acid (FA) conjugated SWNT-Au nanocomposite (SWNT-Au-PEG-FA) is realized, with images acquired in significantly shortened periods of time as compared to that of using nonenhanced SWNT Raman probes. Owing to the strong surface plasmon resonance absorption contributed by the gold shell, the SWNTs-Au-PEG-FA nanocomposite also offers remarkably improved photothermal cancer cell killing efficacy. This work presents a facile approach to synthesize water-soluble noble metal coated SWNTs with a strong SERS effect suitable for labeling and fast Raman spectroscopic imaging of biological samples, which has been rarely realized before. The SWNT-Au-PEG nanocomposite developed here may thus be an interesting optical theranostic probe for cancer imaging and therapy.
425 citations
TL;DR: To the best knowledge, this work is the first to use systemically administrated conductive polymer nanoparticles for highly effective in vivo PTT treatment in animals and encourages further explorations of those organic nanomaterials for cancer theranostic applications.
Abstract: In recent years, a wide range of near-infrared (NIR) light absorbing nanomaterials, mostly inorganic ones, have been developed for photothermal therapy (PTT) of cancer. In this work, we develop a novel organic PTT agent based on poly-(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS), a conductive polymer mixture with strong NIR absorbance, for in vivo photothermal treatment of cancer. After being layer-by-layer coated with charged polymers and then conjugated with branched polyethylene glycol (PEG), the obtained PEDOT:PSS-PEG nanoparticles are highly stable in the physiological environment and exhibit a stealth-like behavior after intravenous injection with a long blood circulation half-life. As a result, an extremely high in vivo tumor uptake of PEDOT:PSS-PEG attributed to the tumor-enhanced permeability and retention effect is observed. We further use PEDOT:PSS-PEG as a PTT agent for in vivo cancer treatment and realize excellent therapeutic efficacy in a mouse tumor model under NIR light irradiation at a low laser power density. Comprehensive blood tests and careful histological examination reveal no apparent toxicity of PEDOT:PSS-PEG to mice at our treated dose within 40 days. To our best knowledge, this work is the first to use systemically administrated conductive polymer nanoparticles for highly effective in vivo PTT treatment in animals and encourages further explorations of those organic nanomaterials for cancer theranostic applications.
393 citations
TL;DR: This work develops multifunctional nanoparticles (MFNPs) with highly integrated functionalities including upconversion luminescence, superparamagnetism, and strong optical absorption in the near-infrared (NIR) region with high photostability with outstanding photothermal therapeutic efficacy in a murine breast cancer model.
TL;DR: It is demonstrated that nanographene can be specifically directed to the tumor neovasculature in vivo through targeting of CD105 (i.e., endoglin), a vascular marker for tumor angiogenesis, and establishes CD105 as a promising vascular target for future cancer nanomedicine.
Abstract: Herein we demonstrate that nanographene can be specifically directed to the tumor neovasculature in vivo through targeting of CD105 (i.e., endoglin), a vascular marker for tumor angiogenesis. The covalently functionalized nanographene oxide (GO) exhibited excellent stability and target specificity. Pharmacokinetics and tumor targeting efficacy of the GO conjugates were investigated with serial noninvasive positron emission tomography imaging and biodistribution studies, which were validated by in vitro, in vivo, and ex vivo experiments. The incorporation of an active targeting ligand (TRC105, a monoclonal antibody that binds to CD105) led to significantly improved tumor uptake of functionalized GO, which was specific for the neovasculature with little extravasation, warranting future investigation of these GO conjugates for cancer-targeted drug delivery and/or photothermal therapy to enhance therapeutic efficacy. Since poor extravasation is a major hurdle for nanomaterial-based tumor targeting in vivo, this study also establishes CD105 as a promising vascular target for future cancer nanomedicine.
TL;DR: A family of novel photoacoustic contrast agents that are based on the binding of small optical dyes to single-walled carbon nanotubes (SWNT-dye) and conjugated with cyclic Arg-Gly-Asp peptides to molecularly target the α(v)β(3) integrin, which is associated with tumor angiogenesis.
Abstract: Photoacoustic imaging is a unique modality that overcomes to a great extent the resolution and depth limitations of optical imaging while maintaining relatively high contrast. However, since many diseases will not manifest an endogenous photoacoustic contrast, it is essential to develop exogenous photoacoustic contrast agents that can target diseased tissue(s). Here we present a family of novel photoacoustic contrast agents that are based on the binding of small optical dyes to single-walled carbon nanotubes (SWNT-dye). We synthesized five different SWNT-dye contrast agents using different optical dyes, creating five "flavors" of SWNT-dye nanoparticles. In particular, SWNTs that were coated with either QSY(21) (SWNT-QSY) or indocyanine green (SWNT-ICG) exhibited over 100-times higher photoacoustic contrast in living animals compared to plain SWNTs, leading to subnanomolar sensitivities. We then conjugated the SWNT-dye conjugates with cyclic Arg-Gly-Asp peptides to molecularly target the α(v)β(3) integrin, which is associated with tumor angiogenesis. Intravenous administration of these tumor-targeted imaging agents to tumor-bearing mice showed significantly higher photoacoustic signal in the tumor than in mice injected with the untargeted contrast agent. Finally, we were able to spectrally separate the photoacoustic signals of SWNT-QSY and SWNT-ICG in living animals injected subcutaneously with both particles in the same location, opening the possibility for multiplexing in vivo studies.
TL;DR: This work is the first success of using functionalized GO as an efficient enzyme positive modulator with great selectivity, exhibiting a novel potential of GO, when appropriately functionalized, in enzyme engineering as well as enzyme-based biosensing and detection.
Abstract: The understanding of interactions between nanomaterials and biomolecules is of fundamental importance to the area of nanobiotechnology. Graphene and its derivative, graphene oxide (GO), are two-dimensional (2-D) nanomaterials with interesting physical and chemical properties and have been widely explored in various directions of biomedicine in recent years. However, how functionalized GO interacts with bioactive proteins such as enzymes and its potential in enzyme engineering have been rarely explored. In this study, we carefully investigated the interactions between serine proteases and GO functionalized with different amine-terminated polyethylene glycol (PEG). Three well-characterized serine proteases (trypsin, chymotrypsin, and proteinase K) with important biomedical and industrial applications were analyzed. It is found that these PEGylated GOs could selectively improve trypsin activity and thermostability (60–70% retained activity at 80 °C), while exhibiting barely any effect on chymotrypsin or prot...
TL;DR: Real-time intravital microscopic imaging is used to meticulously examine how two different nanoparticles behave across three different murine tumor models to quantitatively indicate that nanoscale extravasational competence is highly dependent on nanoparticle geometry and is heterogeneous.
Abstract: Delivery is one of the most critical obstacles confronting nanoparticle use in cancer diagnosis and therapy. For most oncological applications, nanoparticles must extravasate in order to reach tumor cells and perform their designated task. However, little understanding exists regarding the effect of nanoparticle shape on extravasation. Herein we use real-time intravital microscopic imaging to meticulously examine how two different nanoparticles behave across three different murine tumor models. The study quantitatively demonstrates that high-aspect ratio single-walled carbon nanotubes (SWNTs) display extravasational behavior surprisingly different from, and counterintuitive to, spherical nanoparticles although the nanoparticles have similar surface coatings, area, and charge. This work quantitatively indicates that nanoscale extravasational competence is highly dependent on nanoparticle geometry and is heterogeneous.
TL;DR: The use of upconversion nanoparticles (UCNPs) as an exogenous contrast agent to track mouse MSCs (mMSCs) in vivo and highlights the promise of using UCNPs as a new type of ultra-sensitive probes for labeling and in vivo tracking of stem cells at nearly the single cell level.
TL;DR: In this special issue, seven review articles and research reports are collected, to summarize and present the latest progress in the exploration of various nano-carbons for theranostic applications.
Abstract: Nano-carbons, including fullerenes, carbon nanoparticles, carbon nanotubes, graphene, and nano-diamonds, are an important class of nanostructures attracting tremendous interests in the past two decades. In this special issue, seven review articles and research reports are collected, to summarize and present the latest progress in the exploration of various nano-carbons for theranostic applications.
TL;DR: It is shown that polyethylene glycol functionalized SWNTs conjugated with protamine (SWNT‐PEG‐PRO) exhibit extremely efficient cell entry into hMSCs, without affecting their proliferation and differentiation.
Abstract: Stem cells have shown great potential in regenerative medicine and attracted tremendous interests in recent years. Sensitive and reliable methods for stem cell labeling and in vivo tracking are thus urgently needed. Here, a novel approach to label human mesenchymal stem cells (hMSCs) with single-walled carbon nanotubes (SWNTs) for in vivo tracking by triple-modal imaging is presented. It is shown that polyethylene glycol (PEG) functionalized SWNTs conjugated with protamine (SWNT-PEG-PRO) exhibit extremely efficient cell entry into hMSCs, without affecting their proliferation and differentiation. The strong inherent resonance Raman scattering of SWNTs is used for in vitro and in vivo Raman imaging of SWNT-PEG-PRO-labeled hMSCs, enabling ultrasensitive in vivo detection of as few as 500 stem cells administrated into mice. On the other hand, the metallic catalyst nanoparticles attached on nanotubes can be utilized as the T2-contrast agent in magnetic resonance (MR) imaging of SWNT-labeled hMSCs. Moreover, in vivo photoacoustic imaging of hMSCs in mice is also demonstrated. The work reveals that SWNTs with appropriate surface functionalization have the potential to serve as multifunctional nanoprobes for stem cell labeling and multi-modal in vivo tracking.
TL;DR: Recently, rare earth upconversion nanophosphors (UCNPs) have emerged as novel imaging agents for small animals as discussed by the authors, with attractive features such as no auto-fluorescence from biological samples and a large penetration depth.
Abstract: Rare-earth upconversion nanophosphors (UCNPs), when excited by continuous-wave near-infrared light, exhibit a unique narrow photoluminescence with higher energy. Such special upconversion luminescence makes UCNPs promising as bioimaging probes with attractive features, such as no auto-fluorescence from biological samples and a large penetration depth. As a result, UCNPs have emerged as novel imaging agents for small animals. In this critical review, recent reports regarding the synthesis of water-soluble UCNPs and their surface modification and bioconjugation chemistry are summarized. The applications of UCNPs for small-animal imaging, including tumor-targeted imaging, lymphatic imaging, vascular imaging and cell tracking are reviewed in detail. The exploration of UCNPs as multifunctional nanoscale carriers for integrated imaging and therapy is also presented. The biodistribution and toxicology of UCNPs are further described. Finally, we discuss the challenges and opportunities in the development of UCNP-based nanoplatforms for small-animal imaging (276 references).
TL;DR: The totality of results clearly demonstrate the exciting potential of the functionalized NPAPF NPs as a NIR fluorescent probe for in vitro and in vivo imaging and diagnostics.
TL;DR: A new concept of carrier-free functionalized drug nanoparticles for targeted drug delivery exhibits significantly enhanced drug efficacy to folate receptor-positive cells with high selectivity and a high drug loading content up to more than 78%.
TL;DR: In this article, a generic strategy to make hybrids incorporating metal nanoparticles and carbon nanosupports with large surface area is reported, which is a one-step, universal approach totally free of additives and by-products.
TL;DR: The results show that water dispersible and highly stable organic NPs would be a promising new class of fluorescent probe for bioapplications in cellular imaging and labeling.
Abstract: We develop a new strategy of using surface functionalized small molecule organic dye nanoparticles (NPs) for targeted cell imaging. Organic dye (2-tert-butyl-9,10-di(naphthalen-2-yl)anthracene, TBADN) was fabricated into NPs and this was followed by surface modification with an amphipathic surfactant poly(maleic anhydride-alt-1-octadecene)-polyethylene glycol (C18PMH-PEG) through hydrophobic interactions to achieve good water dispersibility and bio-environmental stability. It should be noted that no additional inert materials were added as carriers, thus the dye-loading capacity of the resulting TBADN NPs is obviously higher than those of previously reported carrier-based structures. This would lead to much larger absorption and then much higher brightness. The resulting TBADN NPs possess comparable, if not higher, brightness than CdSe/ZnS quantum dots under the same conditions, with favorable biocompatibility. Significantly, TBADN NPs are readily conjugated with folic acid, and successfully applied in targeted cell imaging. These results show that water dispersible and highly stable organic NPs would be a promising new class of fluorescent probe for bioapplications in cellular imaging and labeling. This strategy may be straightforwardly extended to other organic dyes to achieve water dispersible NPs for cell imaging and drug delivery.
TL;DR: An overview of how CNTs are used in different aspects of biomedicine including drug delivery and cancer treatment, bio-sensing, biomedical imaging, as well as tissue engineering is provided.
Abstract: Rapid development in the field of nanomedicine is bringing novel opportunities for improved disease diagnosis and drug delivery. Among various nanomaterials involved in nanomedicine, carbon nanotubes (CNTs) possessing a unique one-dimensional structure with interesting intrinsic mechanical, physical, and chemical properties have been extensively explored for a wide range of applications in biology and medicine. This review article provides an overview of how CNTs are used in different aspects of biomedicine including drug delivery and cancer treatment, bio-sensing, biomedical imaging, as well as tissue engineering. The recent developments, future perspective, and major challenges in this field are discussed.
TL;DR: Much more efforts are still required to develop functional CNT bioconjugates with improved biocompatible coatings and controllable optimal sizes to achieve fast excretion and minimal toxicity, for various applications in biomedicine.
Abstract: Owing to their interesting physical and chemical properties, carbon nanotubes (CNTs) have attracted wide attentions in nanomedicine for applications in biological sensing, drug delivery, as well as biomedical imaging. The in vivo behaviors and toxicology of CNTs in biological systems, which are important fundamental questions, although have been intensively studied in recent years, remain to be clarified as distinctive results have been reported by various teams, confusing the scientific community as well as the public. In this article, we review the research on the in vivo behaviors of CNTs, and summarize the toxicity studies of CNTs in animals by different groups. Similar to other nanomaterials, the in vivo pharmacokinetics and biodistribution of CNTs are closely associated with their surface coatings. The excretion of CNTs from animals may happen via renal and fecal pathways, depending on the CNT surface chemistry, shape, and sizes. Regarding the toxicology of CNTs, which has been a debating topic for years, the administration routes, doses, and again the surface functionalization are critical to the in vivo toxicity of nanotubes. Much more efforts are still required to develop functional CNT bioconjugates with improved biocompatible coatings and controllable optimal sizes to achieve fast excretion and minimal toxicity, for various applications in biomedicine.
Patent•
04 Jul 2012
TL;DR: In this article, the authors provided a polyethylene glycol and polyethylenesimine modified graphene oxide and a preparation method thereof, which can effectively and safely transport nucleic acid serving as a gene transfection reagent into a cell.
Abstract: The invention provides a polyethylene glycol and polyethyleneimine modified graphene oxide and a preparation method thereof The graphene oxide comprises graphene oxide, polyethylene glycol and polyethyleneimine, wherein the polyethylene glycol is of a branched-chain structure, one terminal of each of six branched chains is connected to hydroxyl of a glucose molecule, and the other terminal of each of the six branched chains is amidogen, and the number-average molecular weight of the polyethylene glycol is 10,000; the polyethyleneimine is of a branched-chain structure and has the molecular weight of 25,000; and the polyethylene glycol and polyethyleneimine modified graphene oxide with a height of between 1 and 2nm and a size of between 5 and 50nm is prepared by using the graphene oxide, the polyethylene glycol and the polyethyleneimine as raw materials The polyethylene glycol and polyethyleneimine modified graphene oxide can effectively and safely transport nucleic acid serving as a gene transfection reagent into a cell
TL;DR: Shah et al. as discussed by the authors discuss the fact that although historians often focus on highly lethal diseases, such as smallpox, measles, and the plague, malaria has been equally devastating.
Abstract: S. Shah
New York, NY: Sarah Crichton Books, 2010, 320 pages, $26
Throughout human history, mankind has dealt with many deadly diseases. Although historians often focus on highly lethal diseases, such as smallpox, measles, and the plague, malaria has been equally devastating. This evasive
TL;DR: In this article, high-purity silicon nanowires were synthesized using the high temperature method, and their surface was modified with AgI nanoparticles, and composites of the AgI/SiNW nanostructure were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscope.
Abstract: Silver iodide (AgI) is an interesting material for its superionic conductivity property. In this paper, high-purity silicon nanowires were synthesized using the high temperature method, and their surface was modified with AgI nanoparticles. The composites of the AgI/SiNW nanostructure were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The ionic conductivity of the AgI/SiNW nanostructure changed rapidly at temperatures above 147 °C. Also, the AgI/SiNW nanostructure was the ideal substrate for surface-enhanced Raman scattering in chemical detection, which may be used in the biomedical field. The easy fabrication of the AgI/SiNW nanostructure with good properties makes it possible to be widely employed in nanodevices and biodetection.