ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 12
·2521-2530
·
IF 3.286
Su Ruifang,Zheng Hongru,Dong Shuyue,Sun Rui,Qiao Shangna,Sun Hongjing,Ma Xinyue,Zhang Tiehua,Sun Chunyan
The development of a novel method for melamine detection that uses a FAM–aptamer–G-quadruplex construct due to the efficient quenching ability of an aptamer-linked G-quadruplex is reported herein. The construct, which is labeled with the fluorescent dye 6-carboxyfluorescein (FAM), consists of two parts: a melamine-binding aptamer and a G-rich sequence that can form a G-quadruplex structure. Because of the specific recognition of melamine by the T-rich aptamer, this aptamer folds into a hairpin structure in the presence of melamine, which draws the G-quadruplex closer to the FAM fluorophore, leading to the quenching of the fluorescence of FAM. Thus, a highly sensitive and selective fluorescence strategy for assaying melamine was established. Under optimal conditions, the fluorescence quenching is proportional to the concentration of melamine within the range 10–90 nM, and the method has a detection limit of 6.32 nM. Further application of the method to plastic cup samples suggested that it permitted recoveries of between 97.15% ± 1.02 and 101.92% ± 2.07. The detected amounts of melamine spiked into the plastic cup samples and the corresponding amounts measured by HPLC were in good accordance, indicating that this fluorescent method is reliable and practical. Owing to its high sensitivity, excellent selectivity, and convenient procedure, this strategy represents a promising alternative method of melamine screening.
Graphical abstract
研究领域:
生物化学
·
分析化学
·
食品安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2024
·
IF 5.6
Meiqing Liu,Hongyuan Zhuang,Yun Zhang,Yanwei Jia
Lysozyme (LYZ) plays a crucial role in the body's immune defense system. Monitoring LYZ levels can provide valuable insights into the diagnosis and severity assessment of various diseases. Traditionally, antibody-based sandwich assays are employed for LYZ detection, but they are often time-consuming and operationally complicated. In this research, a novel sandwich FRET biosensor was developed, which enables rapid detection of LYZ based on peptide-functionalized gold nanoparticles (pAuNPs) and FAM-labeled aptamer (Apt-FAM). Initially, a mixture of Apt-FAM and pAuNPs resulted in partial quenching of the Apt-FAM fluorescence emission through an inner filter effect (IFE), with negligible energy transfer because of the electrostatic repulsion between the negatively charged pAuNPs and Apt-FAM. The introduction of LYZ into the mixture drove the specific binding of Apt-FAM and pAuNPs to LYZ, facilitating the formation of a pAuNPs-LYZ-aptamer sandwich structure. The formation of this complex drew the pAuNPs and Apt-FAM into close enough proximity to enable FRET to occur, which in turn effectively quenched the fluorescence emission of FAM. The decrease in FAM fluorescence intensity was correlated with the increasing concentration of LYZ. Thus, a sandwich FRET biosensor was successfully developed for LYZ detection with a linear detection range of 0–1.75 μM and a detection limit of 85 nM. Additionally, the biosensor allowed visual detection of LYZ in a 96-well microplate, with a rapid response time of just 15 s. This study introduces a innovative sandwich FRET biosensor that combines aptamer and peptide recognition elements, offering a fast and antibody-free method for protein detection.
研究领域:
生物传感器
·
分析化学
·
纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL SCIENCES
·
2020
·Vol. 36
·期 12
·1529-1533
·
IF 2.049
Zeng Ni,Guo Yaxin,Xiang Juan
Monitoring the changes in the level of KRAS point mutation (the concentration fraction of the KRAS point mutated DNA to the total DNA) in clinical treatment progress can guide and greatly improve the personalized therapy and therapeutic evaluation of patients with cancer. In this work, based on FRET fluorescence quenching and apyrimidinic site-induced guanine/pterin specific binding, we developed a pterin-FAM-TAMRA tri-color fluorescence sensing system to assess the level of KRAS point mutation in one step. The responses from TAMRA displayed good and similar linear correlations in the range from 60 nM to 2 µM for all four types of DNA, resulting in a common linear equation related to the T-DNA concentration ( N aftAMRA = 2.908 c T-DNA + 0.364). Meanwhile, the responses from pterin showed excellent selectivity to W-DNA and an excellent linear correlation to the W-DNA in the concentration range from 60 nM to 1 µM ( N ΔFpterin =–0.364 c gDNA-G + 0.034). This biosensor has an effective concentration range for detecting KRAS point mutations. Especially, because the apyrimidinic site-induced guanine/pterin binding is selective for the detection of wild-type DNA, the sensing system can be applied for clinical mutation level detection of all kinds of KRAS point mutations (G → A, G → C and G → T) in blood samples, which is crucial for the personalized therapy and therapeutic evaluation of patients with most KRAS-related cancer types.
研究领域:
分子生物学
·
癌症研究
·
生物医学工程
·
遗传学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemNanoMat
·
2026
·Vol. 12
·期 6
·e70310
·
IF 2.6
Feng Feng,Ziteng Zhao,Gongrang Li,Yong Song,Qi An,Yantao Zhao
Traditional antibacterial systems are limited by poor stability of natural enzymes, weak antimicrobial activity of conventional nanozymes, and the need for exogenous H 2 O 2 or pH adjustment, thus failing to meet the demands of clinical wound care. To address these issues, this study constructed a glucose oxidase-glucose-mineral-based composite nanozyme (GLU-GOD-FAM) antibacterial system and systematically evaluated its catalytic mechanism, stability, antimicrobial activity, in vivo wound healing efficacy, and biosafety. Results showed that FAM overcame the inactivation of natural enzymes under high temperature or UV irradiation; GLU-GOD-FAM exhibited a “1 + 1 > 2” synergistic antimicrobial effect, achieving 100% bactericidal rate against E. coli and S. aureus without exogenous H 2 O 2 supplementation or pH adjustment. In vivo, it accelerated the healing of infected and noninfected mouse dorsal wounds and caused no obvious damage to major organs. This stable, efficient, and safe system provides a novel candidate for clinical emergency wound care and postoperative infection control.
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2025
·
IF 7.7
Linling Zhong,Fanpeng Gong,Jing Li,Guizhu Liu,Xin Wen,Fan Yu,Changjun Hou,Sen Yang,Fangyong Zhu,Xianfeng Wang
High-performance detection of cTnI possesses great significance for diagnosis of myocardial infarction. In this work, two kinds of lower-dimensional Cu(II)-loaded polydopamines were synthesized via in-situ polymerization of dopamine for the first time using Cu-pBDC MOFs and Cu-aBDC MOFs as templates. The obtained Cu-ppDA nanosheets and Cu-apDA nanoribbons maintain the original structure of MOFs and exhibit the advantages of large specific surface area and metal coordination effect, which efficiently enhances the adsorption of single-stranded aptamer DNA probe via π–π stacking. Energy transfer from FAM-Apt probe to Cu(II)-loaded pDA occurred, resulting in the fluoresce quenching. The inference of target cTnI assembles with FAM-Apt probe and the releases from FAM-Apt/Cu-ppDA or FAM-Apt/Cu-apDA systems, leading to the fluorescence recovery. This approach enables a simple, rapid, sensitive, and specific detection method for cTnI. By contrast, FAM-Apt/Cu-ppDA system shows a lower LOD than that of FAM-Apt/Cu-apDA. Furthermore, the successful implementation of these two fluorescent sensors for the detection of cTnI in serum samples obtained from mice with myocardial infarction has been demonstrated. The outcomes of this detection aligned with those achieved through the ELISA method, suggesting their promising potential for practical application in early screening for myocardial infarction.
研究领域:
生物医学工程
·
分析化学
·
医学诊断
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Yawen Wu,Xiaolong Chen,Xianfeng Wang,Mei Yang,Faliang Xu,Changjun Hou,Danqun Huo
The effective detection of CA15-3 is of great significance for the postoperative monitoring and early diagnosis of breast cancer. Here, a fluorescent biosensor based on the fluorescence resonance energy transfer (FRET) between the prismatic hollow Metal-polydopamine frameworks (PHMPF) and 6-carboxyfluorescein (FAM)-labeled protein aptamer (FAM-Apt) was established to detect CA15-3. Characterization of SEM, TEM, EDS, FT-IR, XRD and XPS confirmed that the synthesized PHMPF was a polyhedral prismatic hollow organometallic frame containing the elements of C, N, O, and Co. PHMPF can quench the fluorescent group modified on the aptamer efficiently. Under optimized conditions, the proposed fluorescent biosensor can detect CA15-3 low to 2.56 × 10 −5 U mL −1 . In addition, the excellent selectivity and spiked experiments indicate the proposed biosensor owns potential applications for the clinical diagnosis of tumor markers in body fluids.
研究领域:
肿瘤标志物检测
·
生物医学工程
·
临床诊断
✓ 已验证
产品关联
DOI
高影响因子
FIRE AND MATERIALS
·
2024
·Vol. 48
·期 7
·752-764
·
IF 2
Zhengpeng Chen,Xin He,Zhengshuai Cao,Yunfan Li,Denglong Chen,Zhiwang Yang,Ziqiang Lei
With the wide application of epoxy resins in adhesives, electronic packaging materials, and aerospace fields, it is necessary to prepare high-performance flame-retardant epoxy resins to reduce the fire risk caused by their flammability. In this study, the rigid structure intermediate Schiff base (DMDA-SH) was synthesized by condensation reaction of syringaldehyde (SH) with O-Tolidine (DMDA). Then, DMDA-SH-DOPO, a novel P/N-structured biobased flame-retardant curing agent, was synthesized by addition reaction with 9,10-dihydro-9-oxaza-10-phosphame-10-oxide (DOPO) and was applied to the preparation of intrinsic flame-retardant epoxy resin. As expected, DMDA-SH-DOPO has good flame-retardant properties due to the synergistic action of N/P elements. Epoxy resin with only 2.5% DMDA-SH-DOPO (P = 0.16%) can pass the UL-94 V-0 test. Compared with DGEBA/DDM, DMDA-SH-DOPO-7.5's (P = 0.49%) peak heat release rate was reduced by 48.4% and the limiting oxygen index (LOI) reached 27%, making it a flame-retardant material. From the point of view of carbonaceous residue performance, the expansion height of carbon residue after DMDA-SH-DOPO-7.5 combustion is significantly increased, and the amount of carbon residue at 800°C is increased by 36.4%. In addition, appropriate DMDA-SH-DOPO can effectively improve the bending property of epoxy resin. This study provides a new idea for preparing renewable high-performance intrinsic flame-retardant epoxy resin.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FIRE AND MATERIALS
·
2024
·Vol. 48
·期 6
·605-616
·
IF 2
Yang Liu,Hai-Bo Zhu,Ke Shang,Bi Zhao,Gui-De Lin,Jun-Sheng Wang,Jin-Jun Yang
In this work, different kinds of silane coupling agents modified expanded graphite (MEG) fillers were successfully prepared and then incorporated into silicon rubber matrix to fabricate flame-retardant composite materials (SR/MEG). The inserted MEG fillers with siloxane chains exhibited good compatibility with the silicon rubber matrix, which cannot only reduce the negative impact of adding fillers on mechanical properties but also endow the silicon rubber composites with ideal flame retardancy. Subsequently, platinum (Pt) catalyst was incorporated into the SR/MEG composites to prepare SR/MEG/Pt composites, and the synergistic effects of MEG and Pt catalyst on the thermal stability, flame retardancy, and combustion behavior of silicon rubber composites were systematically investigated. The target SR/MEG/Pt composite with appropriate addition of MEG and Pt catalyst can obtain relatively high char residue of 41.9% and limiting oxygen index value of 29.6%, as well as achieve V-0 rating in the vertical combustion test, owing to the formation of expanded and dense silicon–carbon protective layer under the catalysis of Pt catalyst. Moreover, the cone calorimeter test results showed that the peak of heat release rate and total heat release of SR/MEG composites were further reduced after the addition of an appropriate amount of Pt catalyst, manifesting the good synergistic effect of MEG and Pt catalyst on the flame retardancy performance of silicon rubber. The method proposed herein may provide a promising way for fabricating high-performance flame-retardant silicone rubber materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FIRE AND MATERIALS
·
2024
·Vol. 48
·期 8
·858-867
·
IF 2
Jun-Sheng Wang,Ke Shang,Hui-Jing Jiang,Peng-Ju Wang,Hai-Bo Zhu,Gui-De Lin,Xing Jin,Dan Liu,Bi Zhao,Jin-Jun Yang,Teng Fu
In order to improve the dispersibility of inorganic fillers and enhance its ceramifiable flame-retardant efficiency, the ceramifiable flame-retardant silicone rubber composites were prepared using glass powder, zinc borate, ammonium polyphosphate, mica powder, platinum catalyst as ceramifiable flame-retardant agent, and various silane coupling agents as interfacial modifier. The micromorphology, mechanical properties, flame retardancy, thermal stability, and combustion behavior of ceramifiable flame-retardant silicone rubber composites, as well as the flexural strength of the corresponding ceramics generated after pyrolysis of the composites were examined. The results reveal that the inclusion of silane coupling agents improves the dispersibility of ceramifiable flame-retardant agents substantially. The mechanical properties, flame retardancy, thermal stability, and combustion behavior of ceramifiable flame-retardant silicone rubber composites are all improved. When compared to a composite without a silane coupling agent, the tensile strength of the composite can be improved by up to 1.9 times. Only 0.5phr silane coupling agent is required to raise the vertical combustion rating from V-1 to V-0, and the composite with 3 phr KH570 has a LOI value of 38.6. Meanwhile, the heat release rate of the composite is reduced to a certain extent, and the time to ignition and residue are dramatically enhanced after the addition of silane coupling agent in the cone calorimetry test. Moreover, flexural strength of the corresponding ceramics generated after pyrolysis of the composites rapidly increases with increasing silane coupling agent content, which can reach to 24.7 MPa with addition of 3 phr KH570.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
FIRE AND MATERIALS
·
2020
·Vol. 44
·期 6
·814-824
·
IF 1.925
Yalin Xing,YanQiu Li,Zhaojun Lin,Xiao Ma,Hao Qu,Ruilan Fan
Summary A novel bio-based P-N containing intumescent flame retardant melamine starch phytate (PSTM) was prepared via the reaction of phytic acid starch ester with melamine and characterized by Fourier transform infrared, scanning electron microscopy and thermogravimetric analysis (TGA). The effects of PSTM on thermal properties and flammability of rigid polyurethane (PU) foams were analyzed by TGA, limit oxygen index (LOI), vertical burning tests (UL-94) and cone calorimeter measurement. The TGA results demonstrated that the thermal stabilities of PU/PSTM foam at high temperature was enhanced with the increasing additive amount of PSTM. The results showed that PU foam with 30 php PSTM (PU/PSTM-30%) observed an LOI value of 25.9 and a UL-94 rating of V-0. Cone calorimetry data showed that peak heat release rate, total heat release and smoke production rate of PU/PSTM-30% were distinctly lower than that of pure PU. Further experimental results demonstrated that PSTM promotes well charring of PU which could protect the foam from combustion. This work developed a novel bio-based intumescent flame retardant by suing phytic acid and starch as the acid source and carbon source, respectively, which is of great significance to the preparation of environmental-friendly flame retardants.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
FIRE AND MATERIALS
·
2021
·Vol. 46
·期 1
·107-116
·
IF 2.407
Santosh Khanal,Yunhua Lu,Dandan Jin,Shiai Xu
Summary In this study, two layered double hydroxides (LDHs), ZnAl-LDH, and MgAl-LDH, were combined with intumescent flame retardant (IFR) consisting of ammonium polyphosphate and tris (2-hydroxyethyl) isocyanurate to prepare flame retardant high density polyethylene composites. The thermal and flame retardant properties of these composites were investigated by thermogravimetric analysis, limiting oxygen index measurement, and cone calorimetry, while the morphology and chemical structure of the char residue were analyzed by scanning electron microscopy, Fourier transfer infrared spectroscopy, and laser Raman spectroscopy. The results showed that the peak heat release rate (PHRR) of both HD/IFR/Zn-LDH and HD/IFR/Mg-LDH composites was 52.0% and 12.0% lower than that of HD and HD/IFR, respectively, suggesting that there was no difference in the reduction of PHRR between the two LDHs. The use of LDHs resulted in the formation of compact char residue with a high graphitic degree, but no significant increase in tensile strength.
研究领域:
材料科学
·
燃烧学
✓ 已验证
DOI
高影响因子
FIRE AND MATERIALS
·
2024
·Vol. 48
·期 6
·657-667
·
IF 2
Bin Zhang,Shaohua Zeng
The properties and structure of flexible PVC by incorporating zinc borate (ZB)-modified diantimony trioxide (Sb 2 O 3 ) were investigated. The results of flame retardancy and smoke suppression testing indicate that there was an obvious maximum Limited oxygen index (LOI) value of PVC/20 wt.% ZB–Sb 2 O 3 composites reached 37.5% and passed the UL 94 V-0 rating. An obvious synergistic effect between ZB and Sb 2 O 3 was observed by LOI, SDR, and TG. Moreover, remarkable decreases in the smoke density were observed when ZB–Sb 2 O 3 was incorporated into PVC. In addition, the tensile strength and elongation at break of PVC/ZB–Sb 2 O 3 composites was higher than PVC/Sb 2 O 3 composites, and this ameliorative effect was mainly arising from the ZB–Sb 2 O 3 nanoparticles, which reduced the degree of fatal defects on PVC. The addition of ZB and Sb 2 O 3 greatly increased the amount of residual char and apparently improved the mechanical properties of PVC composites. According to scanning electron microscopy photographs of residual char, after thermal decomposition, there were many fragments linked to the condensed phase and the compact char layer. Fourier transform infrared spectroscopy shows the residues char was composed of benzene ring, the flame retardants occurred and the condensed phase with significant interactions.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）