Electrochemical immunosensing offers a rapid and sensitive approach for the detection of C-reactive protein (CRP), yet the development of electrode substrates that simultaneously optimize conductivity and hydrophilicity remains a challenge. Herein, we propose a sustainable 'waste-to-sensor' strategy to fabricate gold nanoparticle-decorated graphene oxide (AuNPs@GO) nanocomposites by recovering gold ions directly from electronic waste. Through a facile one-step in-situ reduction process, the GO precursor undergoes a reduction-oxidation cycle, effectively reducing gold ions to AuNPs while regenerating the hydrophilic GO matrix. This mechanism resolves the conductivity-dispersibility trade-off inherent in conventional graphene derivatives by combining the superior electron transfer capability of AuNPs with the excellent solution processability of GO. By eliminating complex synthesis protocols and reducing agents, this method streamlines the fabrication of sensing interfaces. Subsequently, a hybrid sandwich-type electrochemical biosensor was constructed by immobilizing specific aptamers for CRP capture and employing horseradish peroxidase-labeled antibodies (HRP-AbCRP) for signal amplification. Under optimal conditions, the proposed biosensor exhibited a wide linear range of 0.01-10 000 ng ml-1 and an ultralow limit of detection (LOD) of 0.0023 ng ml-1. This work not only establishes a high-performance platform for clinical diagnostics but also demonstrates a closed-loop, green pathway for the upcycling of precious metals from electronic waste.

Lateral resolution is a key figure of merit for spectroscopy across all applications. Confocal Raman spectroscopy is able to provide chemical and structural information with submicrometre resolution, resulting in widespread use across multiple disciplines of science and technology. However, the lack of agreed-upon measurement standards and appropriate reference samples has hindered uptake. Here, we report the development and demonstration of a reference sample based on indium arsenide (InAs) semiconducting nanowires for measuring the lateral resolution of confocal Raman spectroscopy with a pathway for traceability to the International System of Units (SI). An interlaboratory comparison involving 15 participants from 11 countries has been conducted to rigorously test and demonstrate the suitability of the sample and the method. The study identified required revisions to the measurement protocol to improve the consistency of data analysis and that the long-term operational stability of the reference sample requires further improvement. Based on a revised data analysis protocol, the method delivered consistent results at the 95% confidence level for eight of the nine participants who returned full datasets. Outcomes from this study have contributed to the publication of a new international standard (ISO 23124:2024).

With the advancement of industry in manufacturing, atomic force microscopy (AFM) and transmitted electron microscopy (TEM) are widely used to measure the vertical and lateral size especially in smaller than 1 nm scale, such as the thickness of the graphene and the gate oxide of HfO2 in the semiconductor industry, where accuracy is required. CODATA has recommended the lattice spacing value of ideal Si (220), which is certified to the bulk silicon, but the bulk silicon must first be processed into a suitable specimen before it is used to calibrate AFM and TEM. As a result, this process will perhaps introduce discrepancies due to mechanical strain or contamination. To enable direct calibration of instruments without additional processing after the certified value of the specimen, the certified reference material (CRM) of single atomic step height of SrTiO3 and the lattice spacing of gold film on carbon substrate are developed to calibrate AFM and TEM, respectively. Both CRMs can be valued using the traced X-ray diffractor directly. Moreover, SrTiO3 single crystal and gold film are stable in the end-user environments,as they are widely used in industry. Both CRMs are used in the international laboratory comparisons of graphene oxide thickness measurement by AFM and Si(220) lattice spacing measurement by TEM under VAMAS and APMP/TCMM, which shows the CRMs are reliable and requisite. Currently, these CRMs and valid measurement methods are used in semi-conductor industry and graphene related two-dimensional material industry. In the future, it will supply valid measurements in more industry fields using these technologies.

Thrombosis remains a major contributor to cardiovascular diseases globally, yet current therapeutic strategies are hindered by narrow therapeutic windows, suboptimal thrombolytic efficacy, and inflammation-driven recurrence. Herein, we reported a second near-infrared (NIR-II) fluorescence imaging (FLI)-guided cascade thrombolytic nanoassembly, MTQPL-Arg@RGD, integrating thrombolytic, antioxidant, and anti-inflammatory functions. This multifunctional nanoassembly was constructed from an aggregation-induced emission (AIE)-active phototheranostic agent (MTQPL), a stimulus-responsive NO donor (l-arginine) and the thrombus-homing peptide c(RGDfC). The integration of NIR-II FLI and AIE sensitively delineated the thrombus site, providing accurate guidance for thrombolysis. Upon 808 nm laser irradiation, the nanoassembly enabled non-invasive and safe thrombolytic therapy through synergistic photothermal/photodynamic (PTT/PDT) effects and hydrogen peroxide-triggered NO gas therapy (GT). Furthermore, it scavenged 82 % of excessive reactive oxygen species, significantly alleviating oxidative stress-induced pro-inflammatory cytokines production. Consequently, 78 % blood reperfusion was realized, effectively restoring blood flow and preventing re-embolism in carotid thrombosis models. This work presents the first multimodal stimulus-responsive nanoassembly for cascade diagnosis and therapy that integrates NIR-II FLI, PTT, PDT, GT, and antioxidant/anti-inflammatory effects, providing a safe, rapid, and minimally invasive approach for time-critical clinical thrombolysis.

Carbon-based materials hold significant potential for electromagnetic absorption applications, however, the development of effective discrete dual-band absorbers remains a formidable challenge. In this study, we synthesized BaTiO3@reduced graphene oxide (BTO@rGO) composite aerogel via ascorbic acid-assisted thermal reduction, enhanced by a freeze-thaw treatment. This treatment induces a bimodal mesoporous structure, with pore size centered at 2.2 nm and 3.9 nm, which significantly boosts the aerogel's specific surface area of 15.95 m2 g-1 . Additionally, the freeze-thaw process enriches the rGO with defect dipoles and reduces the Ba2 + content on the surface sites. These structural and compositional features synergistically contribute to the composite's discrete dual-band absorption characteristic. Specifically, the composite achieves minimum reflection loss values of -13.8 dB in the C-band (4.7-5.7 GHz) and -20.7 dB in the Ku-band (15.4-17.6 GHz) at a thickness of 5.0 mm, which aligns well with the quarter-wavelength theory. This innovative structural design strategy, which transforms single-frequency absorbers into dual-frequency absorbers, offers a novel and effective approach for developing advanced dual-frequency absorbing materials.

Understanding the relationship between structure and properties is critical to the development of solid-state luminescence materials with desired characteristics and performance optimization. In this work, we elaborately designed and synthesized a pair of mononuclear iridium(III) complexes with similar structures but different degrees of cationization. [Ir2-f][2PF6] with two counterions is obtained by simple N-methylation of the ancillary ligand of [Ir1-f][PF6] which is a classic cationic iridium(III) complex. Such a tiny modification results in tremendously different optical properties in dilute solutions and powders. [Ir1-f][PF6] exhibits weak light in solution but enhanced emission in solid-state as well as poly(methyl methacrylate) matrix, indicative of its aggregation-induced emission (AIE) activity. On the sharp contrary, [Ir2-f][2PF6] is an aggregation-caused quenching (ACQ) emitter showing strong emission in the isolated state but nearly nonemissive in aggregation states. Benefiting from the appealing characteristics of mechanochromic luminescence and AIE behavior, [Ir1-f][PF6] has been successfully applied in reversible re-writable data recording and cell imaging. These results might provide deep insights into AIE and ACQ phenomenon of iridium(III) complexes and facilitate the development of phosphorescent materials with promising properties.

Photodynamic therapy (PDT) relying on photosensitizer-induced production of reactive oxygen species (ROS) for killing cancer cells has emerged as a non-invasive anti-cancer strategy. Compared with oxygen-dependent type-II photosensitizers (PSs) for PDT, the development of intrinsic oxygen-independent type-I ones is highly desired but remains a challenge. In this work, two netural Ir(III) complexes that can produce type-I reactive oxygen species, namely MPhBI-Ir-BIQ (Ir-1) and NPhBI-Ir-BIQ (Ir-2), were synthesized. Bright deep-red emitting nanoparticles with moderate particle size are beneficial for imaging-guided PDT. In in vitro experiments, importantly, the excellent biocompatibility, the targeting of lipid droplets (LDs), and the type-I ⋅OH and O2 ⋅- generation promoted effective photodynamic activity. This work will guide the building of type-I Ir(III) complexes PSs and can provide advantages for potential clinical applications under hypoxic conditions.

Exploring interfacial engineering in metal oxide/reduced graphene oxide composite becomes a hotspot in the field of electromagnetic wave (EMW) absorption. In this work, three-dimensional (3D) porous ZnFe2O4/ reduced graphene oxide (ZFO/rGO) composite aerogel was synthesized in situ by a hydrothermal reduction method combined with freeze-drying technique. The results reveal that dispersed ZFO nanoparticles (NPs) are bonded to defect-rich 3D conductive rGO skeleton in a bridging mode with Fe-O-C, resulting in en-hanced conduction loss. Consequently, the defect-rich ZFO/rGO composite aerogel exhibits an outstanding EMW absorbing properties: a minimum reflection loss (RLmin) value of - 29.12 dB and an effective ab-sorption bandwidth (EAB with RL less than -10 dB) of 3.57 GHz at an ultra-thin matching thickness of 1.51 mm. This work provides a new strategy for constructing defect-rich graphene-based composite aerogel as an efficient EMW absorbing materials.(c) 2023 Elsevier B.V. All rights reserved.

Recently, non-magnetic carbon-based composite has been regarded as one of the most promising electromagnetic wave absorbing (EMWA) materials. How to realize high EMWA performances at ultra-thin matching thickness is a hot research topic. In this study, a strategy to construct three-dimensional (3D) porous BaTiO3@reduced graphene oxide (BTO@rGO) composite aerogel was performed by successively hydrothermal process, chemical reduction and freeze-drying. The results show that defect-rich BTO nanoparticles are dispersedly immobilized into 3D conductive rGO framework by a form of Ba2+ bonding to rGO, enhancing conduction loss and dipole polarization, which contributes to enhanced EMWA performance. As a result, a minimum reflection loss of-50.49 dB with a matching thickness of only 1.46 mm, along with an effective absorption bandwidth of 3.74 GHz (13.07 GHz-16.81 GHz) with a matching thickness of only 1.39 mm, is achieved for 3D porous BTO@rGO composite aerogel. Therefore, this study paves a way for designing and preparing excellent non-magnetic EMWA materials at ultra-thin matching thickness.

Exploring polymer-based films with high energy density and low cost is important, because they have potential applications in flexible electronic equipment. In this paper, we investigated the evidence of structure changes in multilayer films and elaborated on the part of interface effects on dielectric properties. Polyvinylidene fluoride (PVDF) and poly (vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) were spun-coated to form multilayer polymer films. The PVDF/P(VDF-HFP)/PVDF multilayer film has an improved breakdown strength of 4492 kV cm-1 and a discharged energy density of 6.24 J cm-3. According to experimental results, an increase in breakdown strength is caused by an improvement in leakage current and a reduction in ferroelectric beta-phase. The high breakdown strength of multilayer films contributes to the improvement of energy storage density. This work will provide a process method for creating low cost, defect-free, high energy density polymer capacitors.

Flake thickness is one of the defining properties of graphene-related 2D materials (GR2Ms), and therefore requires reliable, accurate, and reproducible measurements with well-understood uncertainties. This is needed regardless of the production method or manufacturer because it is important for all GR2M products to be globally comparable. An international interlaboratory comparison on thickness measurements of graphene oxide flakes using atomic force microscopy has been completed in technical working area 41 of versailles project on advanced materials and standards. Twelve laboratories participated in the comparison project, led by NIM, China, to improve the equivalence of thickness measurement for two-dimensional flakes. The measurement methods, uncertainty evaluation and a comparison of the results and analysis are reported in this manuscript. The data and results of this project will be directly used to support the development of an ISO standard.

Raman spectrum and electron back scattered diffraction (EBSD) were employed to study the resolution and repeatability of stress measurement at Si (001) and Si (111) nanoindentations. The results revealed that anisotropic stress distributions were generated around Si (001) and Si (111) nanoindentations. Both Raman and EBSD had good stress resolution when they were used to measure residual stress on monocrystalline silicon. The stress resolutions of Raman on Si (001) and Si (111) were 0.43 MPa and 3.64 MPa, respectively. The stress measurement repeatability of Raman on Si (001) and Si (111) were respectively 1.69 MPa and 32.58 MPa, which was attributed to the smaller compliance tensor part of Si (001) stress calculation equation. The stress resolutions of EBSD on Si (001) and Si (111) were 0.13 MPa and 0.22 MPa, respectively. The stress measurement repeatability of EBSD on Si (001) and Si (111) were respectively 39.22 MPa and 19.15 MPa.

荧光量子效率是发射与吸收的光子数之比,是表征荧光材料发光性能的关键参数.然而,用于绝对法测量荧光量子效率的光路和探测器未经校准溯源或是校准方法不当,会造成测量光谱的不准确,进一步影响荧光量子效率计算结果的不准确.采用汞氩灯对单色仪进行校准,保证了激发波长和发射波长的准确性,利用标准辐射源对光路、发射单元单色仪和探测器进行光谱相对强度校准,保证了激发波段和发射波段光谱相对强度的准确性;最后从测量模型出发,对测量不确定度进行了分析,得到在300～360 nm的激发光波段和370～900 nm的发射光波段内相对合成标准不确定度为3.58％,相对扩展不确定度为7.16％,k=2.通过对单色仪波长校准以及对光谱相对强度进行校准,为荧光量子效率的准确测量提供了参考.

热电材料是一种能够实现热能与电能直接转换的功能材料,由于无法有效降低块体热电材料的热导率,其性能研究进展缓慢.自上世纪90年代初Hicks等提出了低维化能够显著提高热电材料性能的理论后,薄膜热电材料开始受到广泛关注.低维化提高材料性能的原因主要是材料在低维化后能够产生量子限制效应,使得电子在被压缩维度的运动受到限制.首先,在费米能级附近,与Seebeck系数呈正相关的电子态密度会增大,导致低维热电材料的Seebeck系数相比块体材料显著增大.其次,与块体材料相比,薄膜材料存在更多能够散射声子的晶界,能有效降低晶格热导率.在这两种效应的共同作用下,材料的热电优值(ZT值)能够显著增大.低维热电材料的研究初期主要是通过数学模型和数值计算,从理论上证明量子效应会影响材料的Seebeck系数和电导率,且能实现二者的独立控制,从而提高材料的ZT值.后期的实验数据证明,通过合适的热处理工艺能够有效降低薄膜材料的缺陷,提高其综合性能.因此,热处理工艺的改进对性能的提升也非常重要.热电材料性能的提升离不开制备工艺的进步.为了获得低维化的热电材料,多种薄膜材料制备工艺被用于样品的制备,且不同的制备工艺各有优缺点.Bi-Te基合金不仅可用于低温发电还可用于低温制冷,是目前应用最广泛的低温热电材料,虽然其块体状态下的热电性能研究已趋于完善,但其薄膜状态下热电性能的理论研究还相差甚远,因此Bi-Te基低温薄膜热电材料成为研究热点.本文介绍了国内外采用不同制备工艺生长Bi-Te基热电薄膜材料的发展状况以及热电性能测试方法,提出了在目前发展薄膜热电材料时需要重点关注的方面,并对低维热电材料的发展方向进行了阐述.

There is a pressing need for reliable, reproducible and accurate measurements of graphene’s properties, through international standards, to facilitate industrial growth. However, trustworthy and verified standards require rigorous metrological studies, determining, quantifying and reducing the sources of measurement uncertainty. Towards this effort, we report the procedure and the results of an international interlaboratory comparison (ILC) study, conducted under Versailles Project on Advanced Materials and Standards. This ILC focusses on the comparability of Raman spectroscopy measurements of chemical vapour deposition (CVD) grown graphene using the same measurement protocol across different institutes and laboratories. With data gathered from 17 participants across academia, industry (including instrument manufacturers) and national metrology institutes, this study investigates the measurement uncertainty contributions from both Raman spectroscopy measurements and data analysis procedures, as well as provides solutions for improved accuracy and precision. While many of the reported Raman metrics were relatively consistent, significant and meaningful outliers occurred due to differences in the instruments and data analysis. These variations resulted in inconsistent reports of peak intensity ratios, peak widths and the coverage of graphene. Due to a lack of relative intensity calibration, the relative difference reported in the 2D- and G peak intensity ratios ( I2D/IG ) was up to 200%. It was also shown that the standard deviation for Γ2D values reported by different software packages, was 15× larger for Lorentzian fit functions than for pseudo-Voigt functions. This study has shown that by adopting a relative intensity calibration and consistent peak fitting and data analysis methodologies, these large, and previously unquantified, variations can be significantly reduced, allowing more reproducible and comparable measurements for the graphene community, supporting fundamental research through to the growing graphene industry worldwide. This project and its findings directly underpin the development of the ISO/IEC standard ‘DTS 21356-2—Nanotechnologies—Structural Characterisation of CVD-grown Graphene’.

Defect engineering has attracted significant interest in perovskite oxides because it can be applied to op-timize the content of intrinsic oxygen vacancies (V-O) for improving their recoverable energy-storage density (W-rec). Herein, we design 0.84Bi(0.5+x)Na(0.5-x)TiO(3)-0.16KNbO(3) (-0.02 <=& nbsp;x <=& nbsp;0.08) relaxor ferroelectric ceramics with A-site defects and discuss the influence of VO on W-rec. The composition with x = 0.02 has a high W-rec (3.35 J/cm(3)) as well as a high efficiency (eta = 91%) at 240 kV/cm, and exhibits excellent temperature, fre-quency, and fatigue stabilities. This optimized composition also provides a large discharge-energy-density (W-D = 1.0 J/cm(3)), a high power-density (P-D = 66 MW/cm(3)), a fast discharge-rate (122 ns) at 150 kV/cm, and favorable temperature-induced charge-discharge properties (CDPs). Electron paramagnetic resonance, X-ray photoelectron, and Raman spectroscopic results reveal that the outstanding comprehensive perfor-mance of the designed materials is attributed to the coupling effect of low contents of dimeric (Ti'(Ti -& nbsp;) V-O center dot )(x) & BULL; clusters and high contents of trimeric (Ti'(Ti)& nbsp;- V-O center dot center dot & nbsp;- Ti'(Ti))(x) clusters. This work provides key insights relevant for developing lead-free ceramics with excellent energy-storage properties (ESPs). (C)& nbsp;2022 Elsevier B.V. All rights reserved.

Strain states, microstructures and dislocations at the crack tips of Si (001) and Si (111) were studied by employing Electron Back-Scattered Diffraction, Transmission Electron Microscope, Crosscourt software and Geometric Phase Analysis. The evolutionary mechanisms of microstructures in monocrystalline silicon were explored based on experimental results and classical fracture mechanics theories. The results revealed that the strain values at both sides of Si (001) crack were different among the six strain components. The strain distribution in the crack region was anisotropic. There were strain concentration zones at the crack tips of Si (001) and Si (111). The further crack propagation was inhibited by strain concentration zones. Many dislocations generated at the crack tips revealed that plastic deformation had happened. Dislocation generation was the root cause of plastic deformation and strain concentration. The initiation and movement of dislocations, and the nucleation and propagation of cracks were evolutionary mechanisms of two nonlinear microstructures, which were coexisting and competing and were the quasi-cleavage cracking mechanisms of cracks in silicon materials.

厚度评定是石墨烯相关材料领域的重要课题,原子力显微镜是测量纳米级厚度最直接的手段.由于测量过程中噪声和表面粗糙度等多种因素的影响,根据原子力显微镜形貌数据准确评定厚度仍存在困难.本文利用原子力显微镜测量云母基片上的氧化石墨烯形貌,采用直方图方法分析其厚度.通过对比分析基于区域和基于剖面线的直方图方法,揭示了影响直方图方法评定结果的因素.结果表明直方图方法可以为石墨烯相关材料厚度计量提供有效信息.

A multiferroic BiFeO3 (BFO) catalyst was fabricated through a mild one-pot hydrothermal process with a bath-ultrasound assisted dissolution of Fe(NO3)(3)center dot 9H(2)O for 30 min. X-ray photoemission spectroscopy revealed that the BFO (BFO-u) catalyst with US assisted dissolution of Fe(NO3)(3)center dot 9H(2)O in the synthetic process exhibited high Fe2- and OH- levels, which could be explained to be Fe3+ + H2O ->()))) Fe2+ + H+ + (OH)-O-center dot. As a result, BFO-u catalyst activated potassium peroxymonosulfate (PMS) efficiently for degrading tetracycline hydrochloride. In particular, visible-light assisted activation of PMS over BFO-u catalyst exhibited the highest degradation rate constant, at 0.352 min(-1). Species-trapping experiments revealed that the presence of PMS promoted the generation of (OH)-O-center dot, center dot O(2)(- )and O-1(2) that all participated in degrading TCH, in which O-1(2) was primarily contributed to the degradation. Also, BFO-u catalyst was stable and recyclable and thus suitable for practical applications. (C) 2020 Elsevier B.V. All rights reserved.