We demonstrate detection of NO2 down to ppb levels using transistors based on both single and multiple In2O3 nanowires operating at room temperature. This represents orders-of-magnitude improvement over previously reported metal oxide film or nanowire/nanobelt sensors. A comparison between the single and multiple nanowire sensors reveals that the latter have numerous advantages in terms of great reliability, high sensitivity, and simplicity in fabrication. Furthermore, selective detection of NO2 can be readily achieved with multiple-nanowire sensors even with other common chemicals such as NH3, O2, CO, and H2 around.

BackgroundChimeric antigen receptor (CAR) T cell therapy has demonstrated proven efficacy in some hematologic cancers. We evaluated the safety and efficacy of LCAR-B38M, a dual epitope-binding CAR T cell therapy directed against 2 distinct B cell maturation antigen epitopes, in patients with relapsed/refractory (R/R) multiple myeloma (MM).MethodsThis ongoing phase 1, single-arm, open-label, multicenter study enrolled patients (18 to 80 years) with R/R MM. Lymphodepletion was performed using cyclophosphamide 300 mg/m2. LCAR-B38M CAR T cells (median CAR+ T cells, 0.5 × 106 cells/kg [range, 0.07 to 2.1 × 106]) were infused in 3 separate infusions. The primary objective is to evaluate the safety of LCAR-B38M CAR T cells; the secondary objective is to evaluate the antimyeloma response of the treatment based on the general guidelines of the International Myeloma Working Group.ResultsAt data cutoff, 57 patients had received LCAR-B38M CAR T cells. All patients experienced ≥ 1 adverse events (AEs). Grade ≥ 3 AEs were reported in 37/57 patients (65%); most common were leukopenia (17/57; 30%), thrombocytopenia (13/57; 23%), and aspartate aminotransferase increased (12/57; 21%). Cytokine release syndrome occurred in 51/57 patients (90%); 4/57 (7%) had grade ≥ 3 cases. One patient reported neurotoxicity of grade 1 aphasia, agitation, and seizure-like activity. The overall response rate was 88% (95% confidence interval [CI], 76 to 95); 39/57 patients (68%) achieved a complete response, 3/57 (5%) achieved a very good partial response, and 8/57 (14%) achieved a partial response. Minimal residual disease was negative for 36/57 (63%) patients. The median time to response was 1 month (range, 0.4 to 3.5). At a median follow-up of 8 months, median progression-free survival was 15 months (95% CI, 11 to not estimable). Median overall survival for all patients was not reached.ConclusionsLCAR-B38M CAR T cell therapy displayed a manageable safety profile and demonstrated deep and durable responses in patients with R/R MM.Trial registrationClinicalTrials.gov, NCT03090659; Registered on March 27, 2017, retrospectively registeredElectronic supplementary materialThe online version of this article (10.1186/s13045-018-0681-6) contains supplementary material, which is available to authorized users.

We report complementary detection of prostate-specific antigen (PSA) using n-type In2O3 nanowires and p-type carbon nanotubes. Our innovation involves developing an approach to covalently attach antibodies to In2O3 NW surfaces via the onsite surface synthesis of phosphonic acid-succinylimide ester. Electronic measurements under dry conditions revealed complementary response for In2O3 NW and SWNT devices after the binding of PSA. Real-time detection in solution has also been demonstrated for PSA down to 5 ng/mL, a benchmark concentration significant for clinical diagnosis of prostate cancer, which is the most frequently diagnosed cancer.

One-dimensional metal oxide nanowires, such as In 2 O 3 , [1] ZnO, [2] SnO 2 , [3] CdO, [4] and CuO [5] nanowires, have attracted a lot of attention because of their unique properties for applications ranging from nanoelectronic devices to gas sensors. Among them, SnO 2 is particularly interesting and has many important applications. For instance, SnO 2 is a very important n-type semiconductor with a large bandgap (E g = 3.6 eV at 300 K [6] ), thus making it ideal to work as transparent conducting electrodes for organic light emitting diodes and solar cells. [7±9] In addition, SnO 2 thin films have been extensively studied and used as chemical sensors for environmental and industrial applications.[7±9] SnO 2 in the nanowire form has enormous potential to work as building blocks for nanoelectronics, and is also expected to offer superior chemical sensing performance due to the enhanced surface to volume ratio. Despite the utmost importance, only a relatively small effort has been directed toward the synthesis of SnO 2 whiskers, nanorods, and more recently nanobelts. [3,10±12] Much is left to be explored, especially for the synthesis of high-quality, single-crystalline SnO 2 nanowires with precisely controlled diameters below 30 nm, as required for high-performance field-effect nanowire transistors. In this paper, we report an efficient and reliable laser-ablation approach for large-scale synthesis of SnO 2 nanowires. Precise control over the nanowire diameters has been achieved by using monodispersed gold clusters as the catalyst. Detailed material analysis, such as transmission electron microscopy (TEM) and X-ray diffraction (XRD), were used to confirm the single-crystalline nature of our nanowires. In addition, field effect transistors (FETs) have been constructed based on individual SnO 2 nanowires with on/off ratios up to 10 3 . These nanowire transistors were further demonstrated to work as sensitive UV and polarized UV detectors.A quartz tube furnace was used for our SnO 2 synthesis, where a pure Sn target was placed at the upper-stream of the tube outside the hot zone of the furnace, and Si±SiO 2 substrates covered with 20 nm gold catalytic clusters were placed in the middle of the quartz tube. The tube was then purged with 0.02 % oxygen diluted in argon, followed by heating of the furnace to 900 C. The Sn target was then ablated with a Nd:YAG laser to supply Sn vapor, which was carried downstream by the oxygen±argon mixture. The chamber was maintained at 400 torr during the laser ablation, and the typical reaction time used was about 10±30 min. Our synthesis follows the well-known vapor±liquid±solid (VLS) growth mechanism, where the Sn vapor first diffuses into the gold catalytic particles, and grows out and reacts with O 2 to form SnO 2 once the Sn±Au alloy reaches supersaturation. Continued addition of Sn into the Sn±Au nanoparticle feeds the SnO 2 growth and eventually the diameter of the SnO 2 nanowire is directly linked to the catalytic particle size. After cooling down, the samples were characteriz...

High quality MgO/Fe 3 O 4 core−shell nanowires have been successfully synthesized by depositing an epitaxial shell of Fe 3 O 4 onto single crystal MgO nanowires. The material composition and stoichoimetric ratio have been carefully examined and confirmed with a variety of characterization techniques. These novel structures have rendered unique opportunities to investigate the transport behavior and spintronic property of Fe 3 O 4 in its one-dimensional form. Room-temperature magnetoresistance of ∼1.2% was observed in the as-synthesized nanowires under a magnetic field of B ) 1.8 T, which has been attributed to the tunneling of spin-polarized electrons across the anti-phase boundaries.

Optoelectronic memory plays a vital role in modern semiconductor industry. The fast emerging requirements for device miniaturization and structural flexibility have diverted research interest to two-dimensional thin layered materials. Here, we report a multibit nonvolatile optoelectronic memory based on a heterostructure of monolayer tungsten diselenide and few-layer hexagonal boron nitride. The tungsten diselenide/boron nitride memory exhibits a memory switching ratio approximately 1.1 × 106, which ensures over 128 (7 bit) distinct storage states. The memory demonstrates robustness with retention time over 4.5 × 104 s. Moreover, the ability of broadband spectrum distinction enables its application in filter-free color image sensor. This concept is further validated through the realization of integrated tungsten diselenide/boron nitride pixel matrix which captured a specific image recording the three primary colors (red, green, and blue). The heterostructure architecture is also applicable to other two-dimensional materials, which is confirmed by the realization of black phosphorus/boron nitride optoelectronic memory.

We descried a method to synthesize single crystalline Fe3O4 nanotubes by wet-etching the MgO inner cores of MgO/Fe3O4 core-shell nanowires. Homogeneous Fe3O4 nanotubes with controllable length, diameter, and wall thickness have been obtained. Resistivity of the Fe3O4 nanotubes was estimated to be approximately 4 x 10-2 Omega cm at room temperature. Magnetoresistance of approximately 1% was observed at T = 77 K when a magnetic field of B = 0.7 T was applied. The synthetic strategy presented here may be extended to a variety of materials such as YBCO, PZT, and LCMO which should provide ideal candidates for fundamental studies of superconductivity, piezoelectricity, and ferromagnetism in nanoscale structures.

A strategy to covalently attach biological molecules to the electrochemically active surface of indium oxide nanowire (In2O3 NW) mat devices is presented. A self-assembled monolayer (SAM) of 4-(1,4-dihydroxybenzene)butyl phosphonic acid (HQ-PA) was generated on an indium tin oxide (ITO)-coated glass and In2O3 NWs surface. The chemical steps required for surface derivatization were optimized on an ITO surface prior to modifying the In2O3 NWs. The hydroquinone group contained in the HQ-PA SAM was electrochemically oxidized to quinone (Q-PA) at +330 mV. The monolayer of Q-PA was allowed to react with a thiol-terminated DNA. The DNA was paired to its complementary strand tagged with a fluorescence dye. Attachment of DNA was verified using fluorescence microscopy. A device was subsequently prepared on a SiO2-supported mat of In2O3 NWs by depositing gold electrodes on the mat surface. The reaction strategy optimized on ITO was applied to this In2O3 NW-based device. Arrays of In2O3 NWs on a single substrate were electrochemically activated in a selective manner to Q-PA. Activated In2O3 NWs underwent reaction with HS-DNA and gave a positive fluorescence response after pairing with the dye-DNA. The unactivated In2O3 NWs gave no response, thus demonstrating selective functionalization of an In2O3 NW array. This can be considered a key step for the future fabrication of large-scale, inexpensive, nanoscale biosensors.