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Fetal nucleated red blood cells (fNRBCs) in maternal peripheral blood containing the whole genetic information of the fetus may serve for noninvasive pregnant diagnostics (NIPD). However, the fetal cell-based NIPD is seriously limited by the poor purity of the isolated fNRBCs. Recently, the biomimetic cell membrane-camouflaged nanoparticles containing outstanding features have been widely used to detect and isolate rare cells from the peripheral blood samples. In this work, enythrocyte (RBC) and leukocyte (WBC) membranes are fused and coated onto magnet nanoparticles and then modified with anti-CD147 to isolate fNRBCs from the maternal peripheral blood with significant efficiency (∼90%) and purity (∼87%) in simulated spiked blood samples. Further, fNRBCs were isolated and identified from a series of maternal peripheral blood samples coming from pregnant women of 11-13 gestational weeks, and different chromosomal aneuploidies were diagnosed using fNRBCs isolated from maternal blood in early pregnancy. Our strategy may offer additional opportunity to overcome the limitations of current cell-based NIPD platforms.

Blood tests have been a powerful tool for the clinical analysis of many diseases. With the advances in microfluidic technology, two more specific indicators from the circulation system, namely, emerging "liquid biopsy" of circulating tumor cells (CTCs) and fetal nucleated red blood cells (fNRBCs), can be screened and analyzed as a simple blood test for the noninvasive diagnosis of cancers as well as fetal disorders. The unique feature of precisely manipulating a trace of fluid endows microfluidic devices with the ability to isolate CTCs or fNRBCs from numerous blood cells with high performance, which undoubtedly facilitates biomedical applications of these two kinds of rare cells. In this review, advanced developments in microfluidic technologies focusing on the detection and sorting of rare CTCs and fNRBCs from peripheral blood are summarized. The development of microfluidic devices incorporated with various multifunctional microstructures and nanomaterials for enhancing the sensitivity, purity, and viability of CTC or fNRBC detection enables CTC molecular analysis and fNRBC-based noninvasive prenatal diagnosis (NIPD). These microfluidics-based approaches provide great potential opportunities in noninvasive cancer diagnosis or NIPD applications.

Fetal nucleated red blood cells (fNRBC) in maternal peripheral blood has the potential for non-invasive prenatal diagnostics (NIPD), given its intrinsic nature carrying total genetic information of the fetus. Unfortunately, the scarcity of fNRBCs in maternal blood circulation greatly hinders the effective isolation of fNRBCs and its further uses for clinical prenatal diagnostics. Herein, we developed a gelatin nanoparticles (GNPs) decorated microchip that modified with anti-CD147 as specific capture antibody to efficiently isolate fNRBCs from maternal peripheral blood. The corrugated GNP nanocoating on the walls of the channel, together with herringbone grooves in the continuous curved channel design, produced enhanced interactions between fNRBC and the device for better cell capture performance. Furthermore, the captured cells could be gently released for subsequent off-chip analyses, using an enzymatic treatment to dissolve the biodegradable GNP nanocoating. Significant target cell capture efficiency (>80%), release efficiency (∼89%) and purity (∼85%) as well as a high viability of >90% were achieved using simulated spiked samples. fNRBCs were detected from a series of maternal peripheral blood samples ranging from 7 to 13 weeks of gestation, and the diagnostic application for fetal chromosomal disorders was demonstrated. Our strategy may provide new insights into developing an approach to recover fNRBCs from early pregnancy for improved cell-based NIPD.

An inorganic caesium cation was incorporated into perovskite to improve the performance and stability of solar cells with a hole-transport-material free structure in ambient air. A triple cation device with a champion power conversion efficiency of over 15% was achieved, exhibiting superior thermal, long-term and operational stabilities.

Hole transport material free (HTM-free) perovskite solar cells (PSCs) with carbon counter electrode have the advantages of low-cost, good efficiency and high stability. Here in this work, we demonstrate that incorporating Au@SiO2 core-shell NPs into TiO2 scaffold layer increases the power conversion efficiencies (PCEs) of PSCs by improving the light absorption and facilitating carrier transfer or separation through SPR effect. With the optimal concentration of 0.3 wt % Au@SiO2 incorporation, the average PCE of PSCs enhances to 13.85 ± 0.45% from the reference samples of 12.01 ± 0.44%, which is mainly caused by the improved short circuit current density.

Effective capture and release of circulating tumor cells (CTCs) with high viability is still a challenge in medical research. We design a novel approach with efficient yield and high cell activity for the capture and release of CTCs. Our platform is based on TiO2 nanorod arrays coated with transparent MnO2 nanoparticles. We use hydrothermal synthesis to prepare TiO2 nanorod arrays, the MnO2 nanoparticles are fabricated through in situ self-assembly on the substrate to form a monolayer and etched by oxalic acid with low concentration at room temperature. Up to 92.9% of target cells are isolated from the samples using our capture system and the captured cells can be released from the platform, the saturated release efficiency is 89.9%. Employing lower than 2 × 10-3 M concentration of oxalic acid to dissolve MnO2, the viability of MCF-7 cancer cells exceed 90%. Such a combination of the two-dimensional and three-dimensional platforms provides a new approach isolate CTCs from patient blood samples.

Background: Circulating tumor cells (CTCs) are a burgeoning topic in cancer biomarker discovery research with minimal invasive blood draws. CTCs can be used as potential biomarkers for disease prognosis, early cancer diagnosis and pharmacodynamics. However, the extremely low abundance of CTCs limits their clinical utility because of technical challenges such as the isolation and subsequent detailed molecular and functional characterization of rare CTCs from patient blood samples. Methods: In this study, we present a novel density gradient centrifugation method employing biodegradable gelatin nanoparticles coated on silicon beads for the isolation, release, and downstream analysis of CTCs from colorectal and breast cancer patients. Results: Using clinical patient/spiked samples, we demonstrate that this method has significant CTC-capture efficiency (>80%) and purity (>85%), high CTC release efficiency (94%) and viability (92.5%). We also demonstrate the unparalleled robustness of our method in downstream CTC analyses such as the detection of PIK3CA mutations. Conclusion: The efficiency and versatility of the multifunctional density microbeads approach provides new opportunities for personalized cancer diagnostics and treatments.

Anatase TiO2 ultra-thin nanosheets (TiO2-NS) are synthesized by a facile hydrothermal method. Several merits are realized when employing the prepared TiO2-NS as lithium ion battery anode material, compared to TiO2 nanoparticles. Firstly, the as-prepared TiO2-NS has high charge capacities and a specific surface area up to 98.8 m2g−1, which is beneficial for the insertion of lithium ion. Secondly, the large specific surface area is helpful in enlarging the electrode/electrolyte interfacial area. Finally, the EIS result verifies short electron transfer paths. More importantly, the stability of the nanosheet structure is indirectly confirmed by the excellent cycling performance of charge capacity and the curve of charge capacities versus cycle number at different current densities. After galvanostatic charge/discharge of the batteries for 1000 cycles, the HRTEM images of post-mortem batteries directly reveal a good reversibility of the lithium ion insertion/extraction process aided by TiO2-NS. Thus, all these advantages and the special structure facilitate an excellent cycling performance: the charge capacity with the maximum value of 250 mAh g−1 keeps half after 2000 cycles at a current density of 840 mA g−1 (5 C).

The recovery of rare single circulating tumor cells (CTCs) from patients has great potential to facilitate the study of cell heterogeneity and cancer metastasis, which may promote the development of individualized cancer immunotherapy. Herein, a versatile single-cell recovery approach that utilizes an acoustic droplet-induced enzyme responsive platform for the capture and on-demand release of single CTCs is proposed. The platform combines a multifunctional enzyme-responsive gelatin nanoparticle (GNP)-decorated substrate (GNP-chip) for specific capture with an acoustic droplet positioning technique to realize on-demand release of single CTCs. The acoustic droplet dispenser is employed to generate oxidized alginate microdroplets containing the MMP-9 enzyme (OA-MMP-9) with controllable size and precise positioning upon the cell-attached GNP-chip, allowing controlled cell-surface biodegradation under enzymatic reactions followed by calcium chloride (CaCl2) solution treatment to form single-cell encapsulated calcium alginate hydrogels. Benefitting from the existence of hydrogels, the released cells could be efficiently recovered by microcapillary. Results demonstrate that the encapsulated cells maintain good cell morphology in the hydrogels, which allow further single-cell nucleic acid analysis. As a proof-of-concept platform, this approach enables reliable and efficient retrieval of single CTCs and holds the potential for versatility in single-cell analysis systems.

The development of tin-based perovskite solar cells (PSCs) is a promising approach to meet the demand of eco-friendly, lead-free perovskite photovoltaics. Limited to the poor chemical stability of tin perovskites, tin-based PSCs usually have to be fabricated with an inverted device structure and both the device efficiency and stability are highly dependent on the selection of hole transport materials (HTMs). Here, we report the synthesis of inorganic nickel oxide (NiO x ) nanoparticles (NPs) via a soft base precipitation method, which enables us to obtain highly dispersed NiO x NPs over a wide pH window. The as-prepared NiO x NPs are employed as the HTM for formamidinium tin iodide (FASnI3) PSCs, resulting in excellent device efficiency (∼8%) and stability (1200 h). Our study offers a facile strategy for mass production of NiO x NPs and easy access to efficient and robust inorganic HTMs that could further boost the development of high performance tin-based PSCs.

The two-step spin coating process produces rough perovskite surfaces in ambient condition with high humidity, which are unfavorable for the contact between the perovskite film and the low temperature carbon electrode. To tackle this problem, multi-walled carbon nanotubes (MWCNTs) are embedded into the perovskite layer. The MWCNTs can act as charge transport high way between individual perovskite nanoparticles and facilitate the collection of the photo-generated holes by the carbon electrode. Longer carrier lifetime is confirmed in the perovskite solar cells with addition of MWCNTs using open circuit voltage decay measurement. Under optimized concentration of MWCNT, average power conversion efficiency of 11.6% is obtained in hole transport material free perovskite solar cells, which is boosted by ∼15% compared to solar cells without MWCNT.

In this paper, autofluorescent gelatin nanoparticles were synthesized as matrix metalloproteinase (MMP) responsive probes for cancer cell imaging. A modified two-step desolvation method was employed to generate these nanoparticles whose size was controllable and had stable autofluorescence. As glutaraldehyde was introduced as the crosslinking agent, the generation of Schiff base (CN) and double carbon bond (CC) between glutaraldehyde and gelatin endowed these gelatin nanoparticles distinct autofluorescence. Considering MMPs were usually overexpressed on the surface of cancer cells and they had degradation ability toward gelatin, we utilized these nanoparticles as imaging probes to responsively monitor the MMP metabolism of cancer cells according to the luminance change. As fluorescent probes, these nanoparticles had facile synthesis procedure and good biocompatibility, and provided a smart strategy to monitor cancer cell behaviors. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2854-2860, 2016.

A mesoporous SiO2 layer is successfully introduced into the hole transport material free perovskite solar cells by spin-coating a SiO2 paste onto the TiO2 scaffold layer. This SiO2 layer can act as an insulating layer and effectively inhibit the charge recombination between the TiO2 layer and carbon electrode. The variation of power conversion efficiencies with the thickness of SiO2 layer is studied here. Under optimized SiO2 thickness, perovskite solar cell fabricated on the TiO2/SiO2 film shows a superior power conversion efficiency of ∼12% and exhibits excellent long time stability for 30 days.

An optimized two-step sequential deposition method to fabricate hole-transport-layer-free carbon-based methyl ammonium lead bromide (MAPbBr3) perovskite solar cells is reported. Small amounts of MABr are introduced into the PbBr2 precursor solution during the first step to prepare MAPbBr3 perovskite films (labeled as MAPB-xMABr), which promotes the conversion of PbBr2 into perovskite phase and results in denser perovskite films with increased crystallinity, lower trap density, and longer carrier lifetime. After optimization, a maximum power conversion efficiency (PCE) of 7.64% (VOC = 1.36 V) is obtained for MAPB-0.2MABr based solar cells. Significantly, the non-encapsulated devices exhibit excellent long-term stability in ambient air (25–30 °C and 20–30% relative humidity), showing no degradation after a year’s exposure. While, it also shows superior thermal stability with PCE retaining 95% of the initial efficiency after 120 h under thermal stress of 80 °C and 40–70% relative humidity.

Two dimensional materials have promising benefits in photoelectronic devices, including facilitating charge transport and reducing defects in perovskite solar cells (PSCs) and photodetectors (PDs) through interface engineering. Herein, a two dimension polymeric material of graphitic carbon nitride quantum dots (g-CNQDs) interlayer is used to modify the SnO2/perovskite interface in both ambient PSCs and PDs to improve the overall performance. The introduction of g-CNQD layer improves the crystalline quality of sequential perovskite absorber with high phase purity, less grain boundaries, low trap states and suppressed carrier recombination due to the intrinsic cross-linkable feature and relatively smooth surface of g-CNQD. As a result, with optimal modification, fully air-processed PSC reached a champion power conversion efficiency of 21.23% with negligible hysteresis, and the PDs had remarkable performance enhancement. Moreover, our PSCs have good stability in ambient air, keeping over 90% of the initial efficiency after 30 days’ exposure.

Filtration of circulating tumor cells (CTCs) in peripheral blood is of proven importance for early cancer diagnosis, treatment monitoring, metastasis diagnosis, and prognostic evaluation. However, currently available strategies for enriching CTCs, such as magnetic activated cell sorting (MACS), face serious problems with purity due to nonspecific interactions between beads and leukocytes in the process of capturing. In the present study, the tumor-targeting molecule folic acid (FA) and magnetic nanoparticles (MNPs) were coated on the surface of red blood cells (RBCs) by hydrophobic interaction and chemical conjugation, respectively. The resulting engineered RBCs rapidly adhered to CTCs and the obtained CTC-RBC conjugates were isolated in a magnetic field. After treatment with RBC lysis buffer and centrifugation, CTCs were released and captured. The duration of the entire process was less than three hours. Cell counting showed that the capture efficiency was above 90% and the purity of the obtained CTCs was higher than 75%. The performance of the proposed method exceeded that of MACS® beads (80% for capture efficiency and 20% for purity) under the same conditions. The obtained CTCs could be successfully re-cultured and proliferated in vitro. Our engineered RBCs have provided a novel method for enriching rare cells in the physiological environment.

Recently, red blood cell (RBC) membrane-coated nanoparticles have attracted much attention because of their excellent immune escapability; meanwhile, gold nanocages (AuNs) have been extensively used for cancer therapy due to their photothermal effect and drug delivery capability. The combination of the RBC membrane coating and AuNs may provide an effective approach for targeted cancer therapy. However, few reports have shown the utilization of combining these two technologies. Here, we design erythrocyte membrane-coated gold nanocages for targeted photothermal and chemical cancer therapy. First, anti-EpCam antibodies were used to modify the RBC membranes to target 4T1 cancer cells. Second, the antitumor drug paclitaxel (PTX) was encapsulated into AuNs. Then, the AuNs were coated with the modified RBC membranes. These new nanoparticles were termed EpCam-RPAuNs. We characterized the capability of the EpCam-RPAuNs for selective tumor targeting via exposure to near-infrared irradiation. The experimental results demonstrate that EpCam-RPAuNs can effectively generate hyperthermia and precisely deliver the antitumor drug PTX to targeted cells. We also validated the biocompatibility of the EpCam-RAuNs in vitro. By combining the molecularly modified targeting RBC membrane and AuNs, our approach provides a new way to design biomimetic nanoparticles to enhance the surface functionality of nanoparticles. We believe that EpCam-RPAuNs can be potentially applied for cancer diagnoses and therapies.

Nanotechnology possesses the potential to revolutionize the diagnosis and treatment of tumors. The ideal nanoparticles used for in vivo cancer therapy should have long blood circulation times and active cancer targeting. Additionally, they should be harmless and invisible to the immune system. Here, we developed a biomimetic nanoplatform with the above properties for cancer therapy. Macrophage membranes were reconstructed into vesicles and then coated onto magnetic iron oxide nanoparticles (Fe3O4 NPs). Inherited from the Fe3O4 core and the macrophage membrane shell, the resulting Fe3O4@MM NPs exhibited good biocompatibility, immune evasion, cancer targeting and light-to-heat conversion capabilities. Due to the favorable in vitro and in vivo properties, biomimetic Fe3O4@MM NPs were further used for highly effective photothermal therapy of breast cancer in nude mice. Surface modification of synthetic nanomaterials with biomimetic cell membranes exemplifies a novel strategy for designing an ideal nanoplatform for translational medicine.

As "liquid biopsies", circulating tumor cells (CTCs) have been thought to hold significant insights for cancer diagnosis and treatment. Despite the advances of microfluidic techniques that improve the capture of CTCs to a certain extent, recovering the captured CTCs with enhanced purity at the same time remains a challenge. Here, by combining on-chip purification and off-chip enzymatic treatment, we demonstrate a two-stage strategy to enhance the purity of captured cancer cells from blood samples. The on-chip purification introduces a stirring flow to increase the capture sensitivity and decrease nonspecifically bounded cells. The off-chip enzymatic treatment enables the cancer cells to be released from the attached magnetic beads, further improving the purity and enabling next reculture. For the proof-of-concept study, spiked cancer cells are successfully obtained from unprocessed whole blood with high recovery rate (∼68%) and purity (∼61%), facilitating subsequent RNA expression analysis.

Liquid electrolytes employing fluorescent perylene are prepared and applied in dye sensitized solar cells (DSSCs). Due to the excellent down-shifting property of perylene, photons with short wavelength (from about 350 to 440 nm) can be absorbed and then converted to ones with longer wavelength (from 450 nm to 550 nm) which can be more efficiently utilized by DSSCs. As a result, device with optimal concentration of 0.05 M perylene presents an efficient improvement in the short-circuit current density ( J sc ), leading to an increase of 11.6% in the power conversion efficiency (PCE) compared with the reference DSSC based on control electrolyte.

In this work, a single-layer electric separator based on droplet microfluidics is demonstrated for cell sorting. We introduce a droplet pre-charging stratagem to reduce the voltages needed and increase droplet maneuverability. This stratagem and subsequent sorting process is implemented due to the effect of analogous uniform electric fields, which are generated by the 3D electrodes fabricated through injecting conductive silver paste into chambers in the PDMS layer. The mechanism of this droplet pre-charging process is experimentally verified and the amount of the inductive charges is quantitatively calculated. We also analyze the influence of the interaction between droplet size and channel walls on the manipulations of charge-carried droplets under certain electric fields. After parameter optimization, droplets with single cell encapsulated inside are separated out from other ones using this separator, and cell viability assay indicates that good cell status is maintained through the whole electric cascade.

Thin titanium dioxide (TiO2) semiconductor layer with different scattering layers are investigated in dye-sensitized solar cells (DSSCs). Usually, the scattering layer is placed after the photoanode films in order to harvest more incidents light. The scattering layer based on rutile phase TiO2 is prepared, and placed in the different position of the photoanode films (on the surface of the FTO glass, between the two layers of transparent TiO2 film and after the transparent TiO2 film). We use STT, TST and TTS as marks (T and S represent the transparent TiO2 layer and the scattering layer respectively). The result of this study indicates that STT which has the lowest incident light harvesting efficiency demonstrates the highest electron collection efficiency, while TTS which has the highest incident light harvesting efficiency sacrifices the electron collection efficiency greatly. It is discovered that TST, of which the incident light harvesting efficiency basically remains unchanged compared to TTS, reveals higher electron collection efficiency and achieves the maximum photovoltaic conversion efficiency (7.0%). By applying UV-Visible and diffuse reflectance spectroscopy, electrochemical impedance spectroscopy (EIS), the effects of the incident light harvesting and electron collection efficiencies on different cells are analyzed. It makes the best use of this scattering layer and has a reference for the application of other scattering layer types.

Assays toward analysis of rare heterogeneous cells among identical specimen raise a significant challenge in many cell biological studies and clinical diagnosis applications. In this work, we report a disk-like hydrogel bead-based stratagem for rare cell researches at single cell level after a facile microfluidic-based particle synthesis approach. Cells of interested can be encapsulated into alginate droplets which are subsequently solidified into disk-like calcium alginate hydrogel beads and the bead size and cell number inside can be precisely controlled. Due to stability, permeability and disk-like shape of calcium alginate beads, cells immobilized in the disk-like beads can be treated with different chemicals with limited mechanical or fluidic operation influences and observed without distortion comparing with conventional methods or droplet microfluidic methods. Identification of circulating tumor cells, related to early-stage cancer diagnosis, is targeted to demonstrate the potential of our technique in rare cell analysis. This hydrogel bead-based stratagem is performed in immunofluorescence staining treatment and observation of cancer cells from normal hematological cells in blood sample. This method would have a great potential in single cell immobilization, manipulations and observation for biochemical cellular assays of rare cells.

Three-dimensional branched TiO2 architectures (3D BTA) with controllable morphologies were synthesized via a facile template-free one-pot solvothermal route. The volume ratio of deionized water (DI water) and diethylene glycol in solvothermal process is key to the formation of 3D BTA assembled by nanowire-coated TiO2 dendrites, which combines the advantages of 3D hierarchical structure and 1D nanoscale building blocks. Benefiting from such unique structural features, the BTA in full bloom achieved significantly increased specific surface areas and shortened Li(+) ion/electrons diffusion pathway. The lithium-ion batteries based on BTA in full bloom exhibited remarkably enhanced reversible specific capacity and rate performance, attributing to the high contact area with the electrolyte and the short solid state diffusion pathway for Li(+) ion/electrons promoting lithium insertion and extraction.

Microfluidics-based circulating tumor cell (CTC) isolation is achieved by using gelatin-coated silica microbeads conjugated to CTC-specific antibodies. Bead-binding selectively enlarges target cell size, providing efficient high-purity capture. CTCs captured can be further released non-invasively. This stratagem enables high-performance CTC isolation for subsequent studies.

A piezoelectric nanogenerator based on poly(vinylidene fluoride trifluoroethylene) [P(VDF-TrFE)] nanofibers with an Au interdigital electrode (IDT)/P(VDF-TrFE) nanofiber film/well-ordered cylindrical cavity structure was prepared by combining Au IDTs with a rotary collector to obtain highly aligned P(VDF-TrFE) nanofiber arrays. The Au IDTs work not only as parallel electrodes to collect P(VDF-TrFE) nanofibers during electrospinning but also as charge-collecting electrodes in the nanogenerator. The well-ordered cylindrical cavities improve output performance by enhancing the deformation of P(VDF-TrFE) nanofiber films when subjected to external force. The nanogenerator performs well; as an example of application, we demonstrate energy harvesting from human walking, with a peak output voltage of 5 V and a peak short-circuit current of 1.2 μA. Such a device could have practical applications in wearable, self-powered devices.

ZnO films are prepared on glass substrates by pulsed laser deposition (PLD) at different oxygen pressures, and the effects of oxygen pressure on the structure and optoelectrical properties of as-grown ZnO films are investigated. The results show that the crystallite size and surface roughness of the films increase, but the carrier concentration and optical energy gap E-g decrease with increasing oxygen pressure. Only UV emission is found in the photoluminescence (PL) spectra of all the samples, and its intensity increases with oxygen pressure. Furthermore, there are marked differences in structure and properties between the films grown at low oxygen pressures (0.003 and 0.2 Pa) and the films grown at high oxygen pressures (24 and 150 Pa), which is confirmed by the fact that the crystallite size and UV emission intensity markedly increase, but the carrier concentration markedly decreases as oxygen pressure increases from 0.2 to 24 Pa. These results show that the crystal quality, including the microstructural quality and stoichiometry proportion, of the prepared ZnO films improves as oxygen pressure increases, particularly from 0.2 to 24 Pa.

For decades, poly(ethylene glycol) (PEG) has been widely incorporated into nanoparticles for evading immune clearance and improving the systematic circulation time. However, recent studies have reported a phenomenon known as "accelerated blood clearance (ABC)" where a second dose of PEGylated nanomaterials is rapidly cleared when given several days after the first dose. Herein, we demonstrate that natural red blood cell (RBC) membrane is a superior alternative to PEG. Biomimetic RBC membrane-coated Fe(3)O(4) nanoparticles (Fe(3)O(4) @RBC NPs) rely on CD47, which is a "don't eat me" marker on the RBC surface, to escape immune clearance through interactions with the signal regulatory protein-alpha (SIRP-α) receptor. Fe(3)O(4) @RBC NPs exhibit extended circulation time and show little change between the first and second doses, with no ABC suffered. In addition, the administration of Fe(3)O(4) @RBC NPs does not elicit immune responses on neither the cellular level (myeloid-derived suppressor cells (MDSCs)) nor the humoral level (immunoglobulin M and G (IgM and IgG)). Finally, the in vivo toxicity of these cell membrane-camouflaged nanoparticles is systematically investigated by blood biochemistry, hematology testing, and histology analysis. These findings are significant advancements toward solving the long-existing clinical challenges of developing biomaterials that are able to resist both immune response and rapid clearance.

Control over one-dimensional growth of spinel-type LiMn2O4 nanowires is challenging in the area of materials science due to their cubic crystal structure. The current strategy is to use a self-support template to fabricate LiMn2O4 nanowires, which is time-consuming and limits their large-scale commercial production. In this paper, we propose a general strategy to construct well-defined LiMn2O4 nanowires terminated with amorphous carbon at the edges by an ingenious method without using any template. Benefited from its unique carbon-coated nanowire structure, the electrode exhibits a capacitor-like rate performance and battery-like high capacity for long-time cycling. Even after 1500 cycles at an extremely high current density of 30 C, approximately 82% of its initial capacity can still be retained. Significantly, the strategy reported here will be beneficial and revelatory to manufacture other extensive one-dimensional robust carbon-decorated nanowires, paving new ways for future developments of ultrafast rechargeable lithium-ion batteries.

Hydrogen-induced degradation in CaCu 3 Ti 4 O 12 (CCTO) ceramics was studied using an electrochemical hydrogen charging method, in which the silver electrodes of CCTO ceramic pellets were made a cathode in 0.01 M NaOH solution to deposit hydrogen through the electrolysis of water. The dielectric loss was greatly increased and the insulation resistance was greatly decreased after the treatment. X-ray diffraction analysis showed that no new phases were formed. It is proposed that atomic hydrogen is diffused into CCTO lattice and free electrons are formed through the ionization of hydrogen atoms, which lead to the observed degradation. Hydrogen-induced degradation occurs very quickly in CCTO ceramics and it is important to prevent hydrogen-induced degradation in CCTO ceramics.

We demonstrated an enhanced particle focusing in microfluidic channels by using standing surface acoustic waves (SAWs) generated on a piezoelectric substrate. Interdigitized microelectrode arrays patterned by standard photolithography and lift-off techniques are used for both excitation and detection of SAWs. Bragg reflectors (BR) are also integrated to enhance the standing SAW formation. Furthermore, air cavities are introduced in both sides of microfluidic channels made of polydimethylsiloxane (PDMS). Whereas the system without PDMS cover layer showed a loss less than 2db, the absorption loss after adding PDMS structures was also limited to a few db. Consequently, enhanced particle focusing could be easily observed, showing clear advantages of the use of BR and minimized PDMS wall thicknesses.

Aiming to highly efficient capture and analysis of circulating tumor cells, a micropillar device decorated with graphite oxide-coated magnetic nanoparticles is developed for magneto-controllable capture and release of cancer cells. Graphite oxide-coated, Fe3 O4 magnetic nanoparticles (MNPs) are synthesized by solution mixing and functionalized with a specific antibody, following by the immobilization of such modified MNPs on our designed micropillar device. For the proof-of-concept study, a HCT116 colorectal cancer cell line is employed to exam the capture efficiency. Under magnetic field manipulation, the high density packing of antibody-modified MNPs on the micropillars increases the local concentration of antibody, as well as the topographic interactions between cancer cells and micropillar surfaces. The flow rate and the micropillar geometry are optimized by studying their effects on capture efficiency. Then, a different number of HCT116 cells spiked in two kinds of cell suspension are investigated, yielding capture efficiency >70% in culture medium and >40% in blood sample, respectively. Moreover, the captured HCT116 cells are able to be released from the micropillars with a saturated efficiency of 92.9% upon the removal of applied magnetic field and it is found that 78% of the released cancer cells are viable, making them suitable for subsequent biological analysis.

We designed a highly uniform core double-shell (CDS) structure consisting of -NaYF4:Er3+,Yb3+ crystal as core (~400 nm in diameter and ~470 nm in height), amorphous SiO2 as inner shell (~10 nm in thickness), and interconnected anatase TiO2 grains as outer shell (~30 nm in thickness). For device application, various amount of these hexagonal submicroprisms (HSMs) were introduced into TiO2nanoparticles (20-40 nm in diameter) to form a bifunctional nano-submicron composite (NSMC) layer upon a prior prepared transparent TiO2 layer. By utilization of these efficient -NaYF4:Er3+,Yb3+ upconversion cores, near-infrared irradiation can be absorbed and harvested indirectly by dye molecules to broaden the absorption region and produce more electrons. Owing to the excellent insulating properties, SiO2 shell creates a perfect electrical isolation for the UCP cores. Through this method, the problem of electron trapping and capture caused by ligands and defects on the surface of NaYF4:Er3+, Yb3+ crystals can be thoroughly overcome. However, employment of this submicron sized composites can seriously reduce the internal surface area, leading to a less amount of dye loading. By coating of the outer TiO2 shell, the disadvantage of SiO2 shell can be avoided to the utmost extent. Computer simulation results have shown that scattering of 10-25 nm TiO2particles is negligible and effective Mie scatterers are those particles whose dimensions are comparable to the wavelength of light. With the increasing of mixing amount of these submicron sized HSMs, these bifunctional layers become white gradually, indicating their significant scattering effect of incident light. It is experimentally damostrated that performance of DSCs can be effectively enhanced by employing these bifunctional highly uniform core/double-shell(CDS) structure in the photoelectrodes, an efficiency of 8.65% was obtained, which is 120% higher than the device based on bare NaYF4:Er3+,Yb3+ employed photoelectrode.

Aiming to synthesize multiferroic materials in microscale, a microfluidic device capable of generating multiferroic Janus microparticles is demonstrated. Through bonding two polydimethylsiloxane (PDMS) layers “face to face,” laminar flow containing an upper layer and a lower layer can be realized. Accordingly, poly(vinylidene fluoride-trifluoroethylene) ferroelectric polymers and Fe3O4 ferromagnetic particles are separately encapsulated in the two layers of a single droplet. Numerical simulation enables the analysis of cross-mixing between the two counterparts and helps to find an optimized location for adding subsequent ultraviolet treatment, which will polymerize the droplets into Janus particles without any side effect. By modulation of the flow rate, the size of the Janus particles can be precisely tuned. Finally, the ferroelectricity and magnetism of the Janus particles are verified by the magnetization and polarization measurements, indicating the multiferroic nature.

A microfluidic flow sensor based on aligned piezoelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] nanofibers has been developed. The flow sensor is able to linearly measure low flow rates ranging from 13 μl/h to 301 μl/h with a sensitivity of 0.36 mV per 1 μl/h, and the highest voltage difference of 120 mV at a flow rate of 451 μl/h. Moreover, the viscosity of the ethylene glycol aqueous solution ranging from 1 mPa·s to 16.1 mPa·s at 25 °C can be detected in dynamic flow with a stable output. These findings highlight the potential of piezoelectric P(VDF-TrFE) nanofibers in multiferroic applications.

The first report of synthetic diamond involved a high-pressure high-temperature (HPHT) process in which diamond was the thermodynamically stable phase1. Subsequent attempts to make diamond at less extreme conditions culminated in the rapid growth of diamond films by chemical vapour deposition2,3. But the question of whether diamond might be grown in hydrothermal conditions mimicking those under which it is formed in the Earth has been long debated4–6. It seems reasonable to suppose that metals might play a catalytic or solubilizing role in this context, given their role in the HPHT method1, in a recent low-pressure solid-state synthetic approach7 and in the recrystallization of diamond in the Ni–NaOH–C system8. Hydrothermal synthesis of diamond has been explored at some length9–13, but with equivocal results. Here we report evidence from spectro-scopic, diffraction and microscopic techniques which suggest that aggregates, tens of micrometres in size, of small diamond crystals can be grown in a hydrothermal environment from a mixture of carbon, water and metal (usually pure nickel). Crucially, we have been able to distinguish new diamond from the diamond seeds added to nucleate new growth.

In this paper, a gradient mesoporous carbon (GMC) monolith derived from the mixtures of phenolic resin (PF) and ethylene glycol (EG) was prepared by a facile route based on polymerization-induced phase separation under temperature gradient (TG). A graded biphasic structure of PF-rich and EG-rich phases was first formed in preform under a TG, and then the preform was pyrolyzed to obtain the GMC monolith. The TG is mainly induced by the thermal resistance of the preferential phase separation layer at high temperature region. The pore structure of the monolith changes gradually along the TG direction. When the TG varies from 58°C to 29°C, the pore size, apparent porosity and specific surface area of the monolith range respectively from 18 nm to 83 nm, from 32% to 39% and from 140.5 m2/g to 515.3 m2/g. The gradient porous structure of the monolith is inherited from that of the preform, which depends on phase separation under TG in the resin mixtures. The pyrolysis mainly brings about the contraction of the pore size and wall thickness as well as the transformation of polymerized PF into glassy carbon.

Methods for tagging biomolecules with fluorine 18 as immuno-positron emission tomography (immunoPET) tracers require tedious optimization of radiolabeling conditions and can consume large amounts of scarce biomolecules. We describe an improved method using a digital microfluidic droplet generation (DMDG) chip, which provides computer-controlled metering and mixing of 18F tag, biomolecule, and buffer in defined ratios, allowing rapid scouting of reaction conditions in nanoliter volumes. The identified optimized conditions were then translated to bench-scale 18F labeling of a cancer-specific engineered antibody fragments, enabling microPET imaging of tumors in xenografted mice at 0.5 to 4 hours postinjection.