查找使用阿拉丁产品的科研文献

A Biomimetic Chip with Dendrimer-Encapsulated Platinum Nanoparticles for Enhanced Electrochemiluminescence Detection of Cardiac Troponin I

Yun Hui,Weijun Kong,Weiliang Shu,Zhiting Peng,Fengshan Shen,Mingyang Jiang,Zhen Xu,Tianzhun Wu,Wenhua Zhou,Xue-Feng Yu

The measurement of cardiac troponin I (cTnI) is of vital importance for the early diagnosis of acute myocardial infarction. In this study, an enhanced electrochemiluminescent immunoassay for the highly sensitive and precise determination of cTnI was reported. A biomimetic chip with nepenthes peristome surface microstructures to achieve single-layer microbead arrays and integrated microelectrode arrays (MEAs) for ECL detection was microfabricated. Ru@SiO2nanoparticles were prepared as signal amplificators labeling immunomagnetic beads. Dendrimer-encapsulated platinum nanoparticles (Pt DENs) were electrochemically modified on ITO MEAs. The resulting Pt DEN-modified ITO MEAs preserved good optical transparency and exhibited an approximately 20-fold ECL signal amplification compared to that obtained from bare ITO. The method made full use of the biomimetic chip with Pt DENs to develop single-layer immunomagnetic bead arrays with increasingly catalyzed electrochemical oxidation of the [Ru(bpy)3]2+–TPA system. Consequently, a limit of detection calculated as 0.38 pg/mL (S/N = 3) was obtained with excellent selectivity, demonstrating significant potential for the detection of cTnI in clinical diagnostics.

Reactive cold sintering of dense barium sulfate ceramics for high-reliability chip packaging in integrated circuits

Jia Peng Yuan,Bing Liu,Cheng Chao Hu,Kai Xin Song,Yu Hui Huang

Reactive cold sintering (RCS) is an innovative ceramic consolidation technique that combines a low-temperature reaction with the cold sintering process . In this work, equimolar (CH 3 COO) 2 Ba and (NH 4 ) 2 SO 4 were homogeneously mixed to obtain a reactive activator abbreviated as RA and then added to barium sulfate (BaSO 4 ) powder obtaining BaSO 4 – x wt%RA ( x = 5, 7.5, 10, 12.5, and 15). Dense (>96 % theoretical) BaSO 4 ceramics were successfully fabricated via RCS of BaSO 4 – x wt%RA at 200℃ with a constantly applied pressure of 250 MPa. The Woolfrey-Bannister method provided quantitative insights into the activation energy , indicating that RA effectively reduced the energy required for densification . The Vickers hardness (1.76 GPa) and coefficient of thermal expansion (CTE, 18.8 ppm/°C) of the RCSed BaSO 4 ceramics were comparable to the high-temperature (850 °C) sintered counterparts. Moreover, finite element analyses confirmed the high CTE value of the RCSed BaSO 4 ceramics holds great promise for high-reliability chip packaging applications.

Structural color heart-on-a-chip for evaluating the myocardial protection effects of traditional Chinese medicine

Xuhong Guo,Lingyu Sun,Dongyu Xu,Yuanjin Zhao

Many Chinese medicines have shown protective effects on the heart, while their specific effects and modes of action are still lacking of intuitive studies. In this paper, we propose a structural color heart-on-a-chip from layer assembly for evaluating the myocardial protection effects of traditional Chinese medicine. The structural color scaffolds are imparted with a striped microstructure on one side for inducing the alignment of cardiomyocytes, and an inverse opal nanostructure on the other side for optical sensing. Because the scaffold could generate obvious color changes upon cardiomyocyte contraction, its integration into a microfluidic chip provides a simple screening platform to study the pre-protective effects of Chinese medicine against cardiac injury. We have demonstrated that with the induction of doxorubicin, the injured cardiomyocytes presented abnormal morphology, disappeared sarcomere and depressed beating behaviors that could be reflected by reduced structural color changes. On the contrary, traditional Chinese medicine pre-protection can increase the vitality of cardiomyocytes, reduce reactive oxygen species production, and improve the contractile function of cardiomyocytes, which is highly consistent with the known conclusion. These results indicated that our structural color heart-on-a-chip with real-time visualization characteristics could provide an ideal platform for traditional Chinese medicine development and drug screening.

Polydimethylsiloxane micropatterning-aided multi-size biomimetic tumor spheroid-on-a-chip for investigating chemotherapy and photodynamic therapy

Meilin Sun,Jinwei Zhang,Fen Zhang,Zhenghao Deng,Tingting Xuanyuan,Xufang Liu,Danyang Yu,Wenming Liu

Three-dimensional (3D) tumor spheroids are increasingly recognized as promising and prospective models for in vitro cancer research and preclinical screening. However, it remains an unmet need for facile construction of a micro-platform to synchronously produce spheroids with controlled multi-sizes and diverse pathophysiological characteristics for downstream applications. Here, a user-friendly tumor spheroid-on-a-chip system for multi-size biomimetic tumor model fabrication for supporting different antitumor investigations is developed based on the usage of polydimethylsiloxane-micropatterned chip with high fidelity. Simultaneous and massive production of multi-size tumor spheroids with the respective geometric uniformity is achieved on the simple-to-operate chips. The fabricated multi-size spheroids possess multiple native tumor-like features including complicated multilayer arrangement, multiple phenotypical/biochemical gradients, and various microenvironmental molecule and stroma compositions. The applicability of the system in throughput and multi-parallel investigation of multi-size tumor responses to both chemotherapy and photodynamic therapy is experimentally validated too. The size control of tumor models and their biomimetic degree are proved to be important for identifying drug susceptibility and resistance during the antitumor therapy evaluation. This microengineering advancement has potential applications in oncology, drug development, and tissue engineering and provides an insight into the development of the accessible and generalizable microplatform for cancer research.

Full integration of nucleic acid extraction and detection into a centrifugal microfluidic chip employing chitosan-modified microspheres

Xiaoyu Zhao,Yuxin Huang,Xiang Li,Weihao Yang,Yaoyi Lv,Wei Sun,Jiajun Huang,Shengli Mi

Microfluidic devices especially centrifugal ones have attracted great attention in the nucleic acid testing field, due to their automation, high efficiency, and simple operation. In which, nucleic acid extraction is the basic step, laying a foundation for the downstream amplification and detection procedures. Therefore, the integration of nucleic acid extraction on the chip is expected to achieve cost-efficiency, high-speed automation, diagnostic accuracy, and reaction robustness with the respect to real-time detection. In this work, we employ chitosan-modified magnetic microspheres for pH-induced nucleic acid extraction and integrate this approach into a centrifugal microfluidic chip. The microfluidic system comprises cell lysis, nucleic acids capture and release, isothermal amplification, and real-time fluorescence detection, which is manipulated by centrifugal force and magnetic control. The system exhibits comparable extraction and detection performance in respect of acceptable nucleic acid concentration and purity, high detection specificity and stability, as well as fast detection duration. These efforts to improve the integrated microfluidic detection chip could benefit the portable, efficient and simple nucleic acid diagnosis, especially under the resource-limited circumstance.

Microfluidic Flow-through SPME Chip for Online Separation and MS Detection of Multiple Analyses in Complex Matrix

Yujun Chen,Tao Gong,Cilong Yu,Xiang Qian,Xiaohao Wang

Simplifying tedious sample preparation procedures to improve analysis efficiency is a major challenge in contemporary analytical chemistry. Solid phase microextraction (SPME), a technology developed for rapid sample pretreatment, has flexibility in design, geometry, and calibration strategies, which makes it a useful tool in a variety of fields, especially environmental and life sciences. Therefore, it is important to study the coupling between the microfluidic electrospray ionization (ESI) chip integrated with the solid phase microextraction (SPME) module and the electrospray mass spectrometer (MS). In our previous work, we designed a solid phase microextraction (SPME) module on a microfluidic chip through geometric design. However, automation and calibration methods for the extraction process remain unresolved in the SPME on-chip domain, which will lead to faster and more accurate results. This paper discusses the necessity to design a micromixer structure that can produce different elution conditions on the microfluidic chip. By calculating the channel resistances, the microfluidic chip’s integrated module with the micromixer, SPME, and ESI emitters optimize the geometry structure. We propose the annular channel for SPME to perform the resistances balance of the entire chip. Finally, for SPME on a single chip, this work provides a quantitation calibration method to describe the distribution of the analytes between the sample and the extraction phase before reaching the adsorption equilibrium.Keywords:flow-through solid phase microextraction (SPME) on chip;quantitative analysis of flow-through solid phase microextraction (SPME);online separation;eluted;microfluidic chip;mass spectrometer (MS)

On-chip surface-enhanced Raman scattering arrays for selective sensing of NO2 exhaust emissions from construction machinery

Yaping Tian,Ran Xu,Luqing Chen,Yuanyuan Liu,Xinming Nie,Xinyu Liu,Shoufeng Tang,Lulu Qu

Nitrogen oxides from construction machinery exhaust pose a significant threat to the environment and human health. Therefore, effective capture and highly selective detection of NO 2 is of utmost importance. Surface-enhanced Raman scattering (SERS) is a spectroscopic technique that provides molecular fingerprint information and enables qualitative and quantitative analysis of molecules at extremely low concentrations. However, the application of SERS for gas molecules with small scattering cross sections, such as NO 2 , is still in its infancy. Based on this, a sensing device for capturing and selectively detecting NO 2 from construction machinery exhaust was developed. The device consists of a gas collection module and a Raman signal amplification module containing a 4, 4’-diaminodiphenyl disulfide (APDS) probe-modified flexible Au@PDMS chip. The Au@PDMS chip amplifies the Raman signals of molecules, while the APDS selectively and rapidly captures NO 2 . The proximal electron-rich nitrogen atom and the ortho-electron-poor aromatic hydrogen atom of the APDS probe form a stable six-membered ring complex with the N atom of NO 2 , and hydrogen bonding interactions occur between the H atom in APDS and the O atom in NO 2 . This ring complexation allows the Au@PDMS chip to capture NO 2 quickly and effectively, resulting in changes in SERS signals and facilitating quantitative analysis of NO 2 . Combined with the gas detection device, the chip can identify NO 2 within 5 min with a detection limit of 3.5 ppm. This sensor device has high selectivity for NO 2 detection in real exhaust gases and has great potential for practical detection of construction machinery exhaust gases.

Enhancing Luminous Efficiency of Quantum Dot-Based Chip-on-Board Light-Emitting Diodes Using Polystyrene Fiber Mats

Guanwei Liang,Shudong Yu,Yong Tang,Zhou Lu,Yikai Yuan,Zongtao Li,Jiasheng Li

Simultaneous detection of multiple tumor markers by label-free electrochemical immunoassay using chip-like glass carbon electrodes

Huiqiang Wang,Zhanfang Ma

High thermal conductivity and remarkable damping composite gels as thermal interface materials for heat dissipation of chip

Sheng-Chang Ding,Jian-Feng Fan,Dong-Yi He,Lin-Feng Cai,Xiang-Liang Zeng,Lin-Lin Ren,Guo-Ping Du,Xiao-Liang Zeng,Rong Sun

The emerging applications of composite gels as thermal interface materials (TIMs) for chip heat dissipation in intelligent vehicle and wearable devices require high thermal conductivity and remarkable damping properties. However, thermal conductivity and damping properties are usually correlated and coupled each other. Here, inspired by Maxwell theory and adhesion mechanism of gecko's setae, we present a strategy to fabricate polydimethylsiloxane-based composite gels integrating high thermal conductivity and remarkable damping properties over a broad frequency and temperature range. The multiple relaxation modes of dangling chains and the dynamic interaction between the dangling chains and aluminum fillers can efficiently dissipate the vibration energy, endowing the composite gels with ultrahigh damping property (tan δ > 0.3) over a broad frequency (0.01 – 100 Hz) and temperature range (–50 – 150 °C), which exceeds typical state-of-the-art damping materials. The dangling chains also comfort to the interfaces between polymer matrix and aluminum via van der Waals interaction, resulting in high thermal conductivity (4.72 ± 0.04 W m –1 K –1 ). Using the polydimethylsiloxane-based composite gel as TIMs, we demonstrate effective heat dissipation in chip operating under vigorous vibrations. We believe that our strategy could be applied to a wide range of composite gels and lead to the development of high-performance composite gels as TIMs for chip heat dissipation.

A microfluidic chip integrating fluorescence sensor array and electrochemical aptasensor for sensitive quantification of multiple heavy metals

Pan Yi,Wang Li,Chen Shouhui,Wei Xinlin

In response to the coexistence of multiple heavy metals and their complex interactions, this study developed an integrated microfluidic chip that combined a fluorescence sensor array with an electrochemical aptasensor. Various metal nanoclusters stabilized by different ligands were synthesized as fluorescence signal probes with six distinguishable emission wavelengths to form the fluorescence sensor array. Six heavy metal ions (Pb 2+ , Cd 2+ , Hg 2+ , As 3+ , Cr 6+ , and Cu 2+ ) exhibited different influence on the fluorescence intensities and achieved in a variant data matrix for linear discriminant analysis. The quantification of specific heavy metal ions was realized thorough the electrochemical aptasensor, which was constructed using nucleases exonuclease-assisted and nucleic acid amplification technique. The rapid and sensitive detection of Pb 2+ , Cd 2+ , and Hg 2+ was achieved with detection limits as low as 3.327 pg/mL, 7.975 pg/mL, and 1.228 pg/mL, respectively. The above two sensing strategies were successfully assembled into the microfluidic chip, in which the fluorescence sensor array realized the preliminary identification of various heavy metal ions while the electrochemical aptasensor provided a quantitative signal to improve sensitivity. This integrated microfluidic chip could successfully detect Pb 2+ , Cd 2+ , and Hg 2+ in the tea sample. Therefore, the integrated device designed in this study exhibited excellent potential in the screening and quantification of multiple heavy metal ions in complex matrices. Section Graphical

Site-Selective Electrodeposition on a Microelectrode Array Chip for Parallel Detection of Staphylococcus aureus and Escherichia coli

Xiaoyi Wang,Chao Xie,Jiaxin Liao,Xiaoli Wang,Dirk Mayer,Yuting Zhang,Nandi Zhou

Microelectrode arrays (MEAs) hold inherent potential for the parallel analysis of foodborne pathogens; however, their miniaturized scale introduces critical challenges for multitarget detection, including cross-talk between adjacent units during functionalization and a severely limited sensing area that restricts probe immobilization and ultimate sensitivity. To overcome these limitations, a MEA-based aptasensor is constructed by integrating site-selective electrodeposition with a directed molecular allocation strategy for highly sensitive and specific simultaneous detection of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). A graphene oxide-polypyrrole nanocomposite and an AuNPs/chitosan-gold composite were precisely deposited on different microelectrode units, enabling the spatially resolved immobilization of aptamers against S. aureus and E. coli, respectively. Fluorescence and Raman spectroscopy confirmed the selective allocation of the respective aptamers to their targeted electrode units, effectively preventing cross-talk. Using methylene blue as an electroactive probe, the binding of target pathogens to their respective aptamers was quantified by square wave voltammetry. With optimized conditions, the limit of detection for S. aureus and E. coli was as low as 25.4 CFU mL–1 and 8.8 CFU mL–1. Real-sample assays confirmed that the MEA-based aptasensor is a precise and viable tool for high-speed quantification of S. aureus and E. coli, exhibiting considerable potential for applications in environmental and food safety monitoring practices.