查找使用阿拉丁产品的科研文献

Atomically Thin Delta-Doping of Self-Assembled Molecular Monolayers by Flash Lamp Annealing for Si-Based Deep UV Photodiodes

Shannan Chang,Jiajing He,Slawomir Prucnal,Jieyin Zhang,Jianjun Zhang,Shengqiang Zhou,Manfred Helm,Yaping Dan

Delta doping (δ-doping) can find a wide range of applications in advanced metal oxide semiconductor field effect transistors, deep UV photodetectors, quantum devices, and others. In this work, we formed a δ-doping layer in silicon by employing flash lamp annealing to treat the PCl3 monolayers grafted on silicon surfaces. The δ-doping layer is atomically thin (<1 nm). Low-temperature Hall measurements show that the δ-doping layer is in a metallic state and exhibits a weak localization phenomenon, implying that a two-dimensional electron gas is formed. When we form such an n-type δ-doping layer on a highly doped p-type Si substrate, a highly sensitive solar-blind UV photodetector is created, which traditionally was only possible by using wide band gap semiconductors such as gallium nitride (GaN) or silicon carbide (SiC).

Visual Loop-Mediated Isothermal Amplification (LAMP) Assay for Rapid On-Site Detection of Escherichia coli O157: H7 in Milk Products

Shuangshuang Cui,Yong Wei,Can Li,Jian Zhang,Yunfeng Zhao,Xiayu Peng,Fengxia Sun

(1) Background: Rapid on-site testing is an effective method for the detection ofEscherichia coli O157: H7(E. coli O157: H7) in food ingredients and the environment. (2) Methods: In this study, we developed colorimetric loop-mediated isothermal amplification (LAMP) and immunochromatographic test strips (ICTs) for the rapid and visual detection ofE. coli O157: H7. This study designed new specific LAMP primers forE. coli O157: H7virulence island genes. After the LAMP amplification, the double-stranded DNA target sequence labeled with digoxin and fluorescein isothiocyanate (FITC) at both ends was bound to the anti-digoxin antibody on the gold nanoparticles. Subsequently, it was further bound to the anti-FITC antibody at the T line of the ICTs, forming a positive test result. Hydroxynaphthyl blue dye was directly added to the LAMP amplification product. A blue color indicated positive results, while a purple color indicated negative results. (3) Results: Two visualization methods showed high specificity for the target strains. The visualization tests had sensitivities of 5.7 CFU mL−1, and the detection limit of theEscherichia coli O157: H7in artificially contaminated milk samples was 5.7 × 102CFU mL−1, which was consistent with the results of the standard method (LAMP-electrophoresis method) used in commercial inspection. (4) Conclusions: Both methods could be useful in remote and under-resourced areas.

Efficient DNA Extraction Coupled with Fluorescence Loop-Mediated Isothermal Amplification (LAMP) for On-Site Early Warning Detection of Vibrio parahaemolyticus

Liu Fengyi,Geng Qilin,Sun Xue,Lin Jie,Zhu Xuan,Wang Danyang,Zhang Xiao-Hua,Hu Jingjie,Wang Shi,Bao Lisui,Lv Jia

Vibrio parahaemolyticus ( V. parahaemolyticus ), a significant pathogen in aquatic products, necessitates rapid and precise detection to prevent foodborne disease outbreaks. Early detection of bacterial pathogens is crucial for effective prevention and control. In this study, we developed a field-deployable, “sample-in, answer-out” workflow that integrates efficient DNA extraction with visual fluorescence loop-mediated isothermal amplification (LAMP) for the on-site detection of V. parahaemolyticus . This extraction protocol enables efficient one-pot DNA release within 10 min, eliminating the need for additional purification steps. In addition, coupled with an optimized fluorescence LAMP assay targeting V. parahaemolyticus , the entire process—from sample to result—can be completed within approximately 50 min. The optimized assay exhibited high sensitivity, detecting as low as 1 copy/µL of plasmid DNA and 10 CFU per reaction from pure bacterial culture and spiked seawater samples. This extraction-amplification integrated approach demonstrates robust performance and high practicality for on-site early warning and pathogen monitoring in aquaculture safety settings.

Comparative Study on Photocatalytic Degradation of Methylene Blue by Degussa P25 Titania: Pulsed Laser Light Versus Continuous Broad Spectrum Lamp Irradiation

Yamani Zain Hassan

While most technologists use lamp light for the evaluation of catalysts synthesized for photocatalytic processes, some researchers prefer laser light. To conform in judgement, a comparative study of photocatalytically degrading methylene blue is reported, using a model catalyst Degussa P25, under different energies of 355 nm pulsed laser and under lamp (visible light and broader lamp light) irradiations. The used amounts of Degussa P25 after each batch of experiments were characterized by X-ray diffractometry, BET surface area analysis, field emission scanning electron microscopy, energy dispersive X-ray spectrometry and diffuse reflectance spectroscopy. The spectral photocatalytic degradation efficiencies, between broad lamp light and UV pulsed laser light, were comparable. Larger and spherical nanoparticles formation and reduction of BET surface area were noticed under pulsed UV laser beam irradiation of Degussa P25, while such trends were not observed under lamp irradiation for similar incident light intensities. The carbon contents on the surface, even after calcination of used samples at \(500\, ^{\circ }\) C, and the red shift in absorption spectra, were recorded in Degussa P25 used samples for both pulsed UV laser and lamp photocatalysis. Moreover, no change in the phases of Degussa P25 resulted under either types of irradiations during photocatalysis evaluation.

A simple preparation method of carbon dots by weak power bathroom lamp irradiation and their application for nimesulide detection and bioimaging

Jinping Song,Qi Ma,Xiaomin Liang,Sufang Zhang,Lazhen Shen,Yong Guo,Feng Feng

In this work, a novel strategy for synthesizing carbon dots (CDs) with a quantum yield of approximately 15.36% has been established by employing a bathroom lamp as a light source. Compared with other current protocols, the method described here displayed various advantages such as environmentally friendly manipulations and low power and cost. Subsequently, we applied the CDs as a fluorescence probe for the detection of nimesulide (Nim) firstly under the optimal conditions. A linear relationship between ln(F0/F) and the concentration of Nim was obtained in the range from 0.5 μM to 75 μM with a detection limit of 100 nM. In addition, the as-prepared CDs showed excellent biocompatibility and were applied for cell imaging, which presented great potential applications in cell imaging.

A reversible valve-assisted chip coupling with integrated sample treatment and CRISPR/Cas12a for visual detection of Vibrio parahaemolyticus

Hui Wu,Yanju Chen,Qunqing Yang,Cheng Peng,Xiaofu Wang,Mengyao Zhang,Siwenjie Qian,Junfeng Xu,Jian Wu

Vibrio parahaemolyticus ( V. parahaemolyticus ) is regarded as a major cause of seafood-associated illnesses, which has aroused widespread public concern. Here, a rapid and convenient detection method for V. parahaemolyticus detection was established by a reversible valve-assisted chip coupling with CRISPR/Cas12a. With optimized lysis buffer, loop mediated isothermal amplification (LAMP) reagents and CRISPR reagents, the whole detection process from sampling to results could be finished within 50 min. The structure of chip was simple and the cost was low. By relying on three reversible rotary valves and the rotation direction-dependent Coriolis pseudo force, the flow order of liquid and the direction of liquid flow could be precisely controlled. The LAMP amplicons were specifically and sensitively identified by CRISPR/Cas12a. Positive amplification would produce green fluorescent signal while negative amplification generated no fluorescent signal, which could be clearly distinguished by the naked eye. With 600 μL of samples processed, the limit of detection (LOD) for both pure cultured V. parahaemolyticus or spiked shrimp samples could achieve 30 copies/reaction. These illustrated the established method displayed great feasibility for real samples detection. In the future, the chip could also combine with other amplification reactions, like PCR or recombinase polymerase amplification reaction (RPA), to conduct detection by changing the corresponding lyophilized amplification reagents. Overall, the proposed detection platform displays great potential for food safety analysis and clinical diagnostics, especially in resource-limited areas.

A label-free and naked-eye fluorescence turn-on assay for one-pot LAMP detection of foodborne pathogens using AuNCs-Cu2+ complex

Fuyuan Huang,Paner Jiang,Yiliang Chen,Weiwei Wang,Yaxin Han,Chenlu Chen,Guangxin Xiang,Sheng Ye,Laibao Zheng

Loop-mediated isothermal amplification (LAMP) is a rapid and sensitive approach for foodborne pathogen detection; however, a simple, user-friendly, and naked-eye readable readout method remains a challenge. Herein, we synthesized bovine serum albumin stabilized gold nanoclusters (BSA-AuNCs), which exhibit fluorescence quenching upon copper ions (Cu 2+ ) binding and fluorescence recovery in the presence of phosphate ions (PPi). Leveraging this property, we developed a label-free fluorescence turn-on assay for naked-eye LAMP detection by monitoring PPi accumulation under UV light. To mitigate potential cross-contamination risks inherent in LAMP workflows, we integrated the BSA-AuNCs-Cu 2+ complex into the reaction lid, enabling a closed, one-pot detection system. This method demonstrated high sensitivity, detecting Salmonella enterica at concentrations as low as 10 1  CFU/mL within 40 min (excluding nucleic acid extraction process). With its customizable primers and naked-eye visual detection capability, this assay offers a versatile and practical tool for rapid pathogen screening in diverse applications.

Label-free Colorimetric Detection of Viral RNA Based on Clustered Regularly Interspaced Short Palindromic Repeats and Gold Nanoparticles with a Portable Device

Yaqin Zhang,Jianai Chen,Fange Kong,Chunxia Wang,Hangyu Guo,Yingchun Li,Jiahui Lu,Jicheng Zhang,Jiasi Wang,Yulin Zhou

Viral infections, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are some of the most dangerous threats to humans. SARS-CoV-2 has caused a global pandemic, highlighting the unprecedented demand for rapid and portable diagnostic methods. To meet these requirements, we designed a label-free colorimetric platform that combines the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated proteins (Cas) 12a system for naked-eye detection (named LFP). This method utilizes reverse transcription loop-mediated isothermal amplification (RT-LAMP) and the trans-cleavage activity of the CRISPR/Cas12a system to increase the sensitivity and specificity of the reaction. This platform can detect as few as 4 copies/μL of RNA and produces no false positive results when tested against the influenza virus. To better meet the requirements of point-of-care (POC) detection, we developed a portable device that can be applied in resource-poor and densely populated regions. The LFP assay holds great potential for application in resource-limited settings, and the label-free gold nanoparticle (AuNPs) probe can reduce costs, making it suitable for large-scale screening. We expect that the LFP assay will be promising for the POC screening of COVID-19.

Dual isothermal amplification all-in-one approach for rapid and highly sensitive quantification of plasma circulating MYCN gene of neuroblastoma

Ying Liang,Qionglin Wang,Xianwei Zhang,Mengxin Zhang,Bang Du,Weyland Cheng,Huanmin Wang,Lifeng Li,Guangjun Hou,Wancun Zhang

A dual isothermal amplification assay with dual fluorescence signal detection strategy, named dual isothermal amplification all-in-one approach, was developed for rapid, one-step, highly sensitive quantification of plasma circulating MYCN copy number of neuroblastoma (NB). The developed strategy consisted of rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) on a real-time PCR system using highly specific probe, molecular beacon (MB), as detection probe. The developed strategy possessing a broad linear dynamic range of 10 aM to 1 pM for both target gene ( MYCN ) and reference gene ( NAGK ) . The ratio of the MYCN copy number to NAGK copy number (M/N ratio) was detected by the developed approach in cell lines, NB tumor tissues, hepatoblastoma tumor tissues and Wilms’ tumor tissues, to which the M/N ratios were consistent with previous reports. In particular, the M/N ratio in NB clinical tissue specimens and NB plasma specimens detected with the developed approach were in keeping with the standard RT-PCR approach. More importantly, the M/N ratio in NB tissue samples and corresponding plasma samples of NB patients were consistent with each other with a correlation coefficient of 0.9690, indicating that plasma circulating MYCN is a promising indicator for the risk classification of NB.

IoT-integrated and portable real-time LAMP platform with hydroxy naphthol blue (HNB) for universal, low-cost pathogen detection in resource-limited settings

Zhao Haojie,Han Fei,Sun Xinyue,Gao Zexi,Zheng Zeyan,Niu Yajing,Li Wenping,Su Chao,Li Zhonghong,Tang Wenzhi

The timely and cost-effective detection of infectious pathogens is critical for their prevention and control. In this study, a low-cost, portable, and user-friendly WiFi-enabled Internet of Things (IoT) monitoring system was developed for the detection of infectious pathogens. The detection mechanism relies on real-time monitoring of hydroxy naphthol blue (HNB) colorimetric signals, which are triggered by the depletion of Mg 2+ ions during loop-mediated isothermal amplification (LAMP). A 3D-printed, portable reader was developed for both LAMP incubation and real-time HNB signal monitoring. Analysis at an incubation temperature of 65 °C demonstrated the excellent thermal stability of HNB and its linear correlation ( R 2  = 0.9973) with Mg 2+ ion consumption, highlighting its suitability as a real-time indicator. The detection capability was validated using the Nosema bombycis SSU rRNA gene and the Bombyx mori nucleopolyhedrovirus gp41 gene as model targets. The results showed linear relationships ( R 2  > 0.99) between threshold time and log target concentration, with the limit of detection (LOD) reaching 1 copy µL −1 for both targets. Analysis of Nosema bombycis in real samples showed comparable performance to the conventional female moth microscopy method. Furthermore, the IoT-enabled reader allowed for fully automated result reporting via email, facilitating timely implementation of containment measures. This study reported on the development of a portable and user-friendly IoT-based test platform, presenting attractive potential for point-of-care diagnosis in infectious diseases, particularly in resource-constrained settings. Graphical

Simultaneous Detection of Antibiotic Resistance Genes on Paper-Based Chip Using [Ru(phen)2dppz]2+ Turn-on Fluorescence Probe

Bofan Li,Xiaoming Zhou,Hongxing Liu,Huaping Deng,Ru Huang,Da Xing

Antibiotic resistance, the ability of some bacteria to resist antibiotic drugs, has been a major global health burden due to the extensive use of antibiotic agents. Antibiotic resistance is encoded via particular genes; hence the specific detection of these genes is necessary for diagnosis and treatment of antibiotic resistant cases. Conventional methods for monitoring antibiotic resistance genes require the sample to be transported to a central laboratory for tedious and sophisticated tests, which is grueling and time-consuming. We developed a paper-based chip, integrated with loop-mediated isothermal amplification (LAMP) and the “light switch” molecule [Ru(phen)2dppz]2+, to conduct turn-on fluorescent detection of antibiotic resistance genes. In this assay, the amplification reagents can be embedded into test spots of the chip in advance, thus simplifying the detection procedure. [Ru(phen)2dppz]2+ was applied to intercalate into amplicons for product analysis, enabling this assay to be operated in a wash-free format. The paper-based detection device exhibited a limit of detection (LOD) as few as 100 copies for antibiotic resistance genes. Meanwhile, it could detect antibiotic resistance genes from various bacteria. Noticeably, the approach can be applied to other genes besides antibiotic resistance genes by simply changing the LAMP primers. Therefore, this paper-based chip has the potential for point-of-care (POC) applications to detect various gene samples, especially in resource-limited conditions.

Synthesis of photosensitive polyimide for liquid crystal alignment under non-polarised UV ageing lamp irradiation and a study on the possible mechanism of alignment

Gang Zhu,Fei Wang,Wenjie Liu,Xinjian Gong,Pengfei Geng,Zhenwei Gao,Yinghan Wang