TALANTA
·
2022
·
IF 6.556
Haoyang He,Da-Wen Sun,Hongbin Pu,Zhihui Wu
Food aflatoxin B1 (AFB1) contamination greatly threatens human health and its sensitive determination is imperative. In this study, a surface-enhanced Raman scattering (SERS) and fluorescence dual-signal aptasensor was constructed for sensitive AFB1 detection in peanuts, walnuts, and almonds samples. Fluorescent dye cy5 was used as fluorophore and Raman reporter, while polyethyleneimine modified Ag coating magnetic nanoparticles (MNP@Ag-PEI) were utilized to absorb the cy5 modified aptamer (apt-cy5). Results indicated that linear ranges of 0.001–1000 ng/mL and 0.2–20,000 ng/mL with detection limits of 0.45 pg/mL and 0.135 ng/mL for the SERS and fluorescence methods were obtained, respectively, and AFB1 detection in the nut samples using the aptasensor achieved satisfactory recoveries of 95.2%–108.6% for SERS and 94.7%–109.7% for fluorescence. Compared with other mono signal detection, the established aptasensor facilely fused the merits of the two signals and improved the detection accuracy and flexibility.
研究领域:
分析化学
·
食品科学
·
纳米技术
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Sensing and Bio-Sensing Research
·
2015
·
IF 0
Lina Ma,Zhen Lei,Fuyao Liu,Zhenxin Wang
This work reports on a simple and feasible fluorescence resonance energy transfer (FRET) assay for detecting reactive oxygen species (ROS) both in solution and living cell using polydopamine nanoparticle (PDA NP) as energy acceptor and Cy5 labeled single-stranded DNA (Cy5-ssDNA) as energy donor. The Cy5-ssDNA and PDA NPs form self-assembled conjugates (Cy5-ssDNA-PDA NP conjugates) via π-stacking interactions. In the presence of ROS, the PDA NP adsorbed Cy5-ssDNAs can be effectively cleaved, resulting in the release of Cy5 molecules into solution and recovery of fluorescence emission of Cy5. In order to obtain ROS solution, the glucose oxidase-catalyzed oxidation reaction of glucose with O 2 is employed to generate hydrogen peroxide for Fenton-like reaction. The formation of ROS in Fenton-like reaction can be detected as low as glucose oxidase-catalyzed oxidation of 100 pM glucose by the Cy5-ssDNA-PDA NP conjugate-based FRET assay. The recovery ratio of Cy5 fluorescence intensity is increased linearly with logarithm of glucose concentration from 100 pM to 1 μM, demonstrating that the FRET assay has wide dynamic range. In particular, intracellular ROS has been successfully detected in chemical stimulated HepG-2 cells by the Cy5-ssDNA-PDA NP conjugate-based FRET assay with a fluorescence microscopy, indicating that this approach has great potential to monitor ROS in living cells.
研究领域:
分析化学
·
生物化学
·
分子生物学
·
纳米技术
✓ 已验证
DOI
Analytical Methods
·
2015
·Vol. 8
·期 1
·214-221
·
IF 1.821
Ai Gao,Dan Zhang,Xue-Bo Yin
To obtain comprehensive information and to compensate the limits of individual modalities in molecular imaging, the research on dual-modal imaging probes (DMIPs) attracts much interest. Here, we report a reliable and facile procedure to prepare near infrared fluorescence (NIRF)-magnetic resonance (MR) DMIPs using Cy5-labeled, Gd–Al co-doped mesoporous silica nanoparticles (MSNs). Amine-modified, Gd–Al co-doped MSNs were first synthesized through one-step co-condensation. A Cy5-NHS ester was then coupled to the amino groups to produce the DMIPs, which were denoted as Gd–Al@MSNs-Cy5. High intensity NIRF and a relaxation rate (17.7 mM−1 s−1) were observed. Featuring the lower background and the deeper penetration depth, the cutting-edge NIRF imaging was achieved. Moreover, the larger surface area of MSNs could be modified with more NIRF probes, Cy5, for improved NIRF. Following the Solomon–Bloembergen–Morgan theory, enhanced MR performance was illustrated by the relaxation rate because MSNs have a porous structure that enables access of water into the interior, and co-doping with Al in the MSNs promotes the doped amount of Gd. The exchange rate of water is much more accelerated through doping Gd and Al since a disordered pore arrangement is found in Gd–Al co-doped MSNs. The DMIPs in saline were injected into mice through the tail vein for imaging and basic pharmacokinetics studies. They were excreted by the stomach and intestine in 3 h, a circulation time long enough for imaging. Thus, Gd–Al@MSNs-Cy5 are attractive for clinical NIRF-MR dual-modal imaging by integrating the biocompatibility of MSNs, the NIRF of Cy5, and the high MR response of Gd.
研究领域:
生物医学工程
·
分子影像学
·
纳米医学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2022
·Vol. 189
·期 5
·1-10
·
IF 6.408
Wei Jinxiu,Zhu Kai,Chen Zengwei,Yang Zhaoyan,Yang Kuo,Wang Zhuyuan,Zong Shenfei,Cui Yiping
Programed cell death ligand 1 (PD-L1) is a protein biomarker overexpressed on exosomes derived from tumor cells. It plays an important role in tumor diagnosis, screening, evaluation of therapeutic efficacy, and prognosis. In this study, a facile method is presented to detect PD-L1-overexpressing cancer exosomes with high specificity and sensitivity. First, gold nanospheres (GNSs) were attached to the bottom of an eight-well chambered slide by electrostatic adsorption, forming the detection substrate. Then, Cy5-labeled CD63 aptamers (i.e., the capture probes) were modified on the GNSs by Au–S bond. After adding samples containing target exosomes which were stained by membrane dyes DiI in advance, FAM-labeled PD-L1 aptamers (i.e., the immunoprobes) were added to recognize PD-L1 on the target exosomes. By triple-color fluorescence co-localization (TFC) of the Cy5, DiI, and FAM channels, highly sensitive and reliable detection of the PD-L1-overexpressing exosomes was achieved in the concentration range 7.78 × 10 1 to 7.78 × 10 4 particles/mL with a detection limit down to 6 particles/mL. The advantages of the proposed detection method include the following; first, the detection substrate is easy to prepare and convenient to clean. Second, the TFC strategy can completely exclude nonspecific reaction sites and thus significantly improves the accuracy. Such a facile and reliable detection method holds a great potential in exosome-based cancer theranostics. Graphical abstract In this paper, we proposed a triple-color fluorescence co-localization (TFC) strategy to significantly improve the reliability of exosome detection and the detection substrate is easy to prepare and convenient to clean. In addition, the LOD is down to 6 particles/mL, which is quite low compared with other detection methods
研究领域:
癌症生物学
·
纳米技术
·
分子生物学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2021
·
IF 6.057
Tongtong Li,Yan Zhang,Xiaohong Sun,Yanjin Zhang,Yongan Wang,Zhiyong Nie
A fluorescent probe was developed for ratiometric detection of thallium ions in mineral water samples by modifying a G-rich aptamer (PS2.M − 7) with a fluorescence donor (Cyanine-3, Cy 3 ) and a quencher (Cyanine-5, Cy 5 ). The probe had a random coil structure that changed into a G-quadruplex structure upon binding with Tl + . This change in structure decreased the distance between the donor and acceptor moieties, which resulted in fluorescence resonance energy transfer between Cy 3 and Cy 5 . Under optimized conditions, the limit of detection and linear concentration range for Tl + were 30.1 μM (3σ) and 10 μM–10 mM ( R 2 = 0.9981), respectively. This simple and cost-effective fluorescence sensor provided satisfactory results for detection of thallium ions in spiked mineral water samples.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2023
·Vol. 148
·期 3
·675-682
·
IF 4.2
Chenhui Hao,Jinxiu Wei,Shenfei Zong,Zhuyuan Wang,Hong Wang,Yiping Cui
Ag+ ions are widely used in various fields of human life due to their unique properties and they threaten the environment and human health. The traditional methods for Ag+ detection commonly suffer from disadvantages including limited sensitivity, expensive equipment and complicated operating steps. Herein, we developed a highly specific dual-color fluorescence co-localization (DFC) strategy based on the C–Ag+–C structure for Ag+ detection. In this strategy, Ag+ ions can be captured to form C–Ag+–C base pairs, and these ions enable single-stranded DNAs to form double strands. The DFC strategy can exclude nonspecific interaction sites and greatly improve the sensitivity and specificity. By DFC of the QDs and Cy5 linked to the DNA strands, highly sensitive Ag+ detection was achieved in the concentration range from 0.14 pM to 200 nM, with a limit of detection (LOD) of 0.14 pM. Moreover, this method has been applied for the detection of Ag+ ions in real environmental samples with satisfactory recoveries. We believe that the DFC strategy is promising for Ag+ detection.
研究领域:
分析化学
·
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Neurotherapeutics
·
2024
·
IF 5.6
Zhiyuan Shen,Yuxuan Lu,Yingying Ren,Zhaoxia Wang,Jianwen Deng,Ding Nan,Jingjing Jia,Weiwei Yu,Yunyi Jin,Wei Sun,Yining Huang,Xiaozhong Qu,Haiqiang Jin
The precise oxygen content thresholds of ischemic deep parenchymal (OCIDP) and that in cortical microcirculation (OCCM), which leads to ischemic penumbra converting into the infarcted core, remain uncertain. This study employed an invasive fiber-optic oxygen meter and a newly developed oxygen-responsive probe called RuA 3 -Cy5-rtPA (RC-rtPA) based on recombinant tissue-type plasminogen activator (rtPA) to examine the oxygen content thresholds. A mouse model of middle cerebral artery occlusion was generated and animals were randomly divided into a sham, 24-h reperfusion after 3-h ischemia (IR 3-h), and IR 6-h groups, all of which were sacrificed following reperfusion. Stroke severity was evaluated based on the infarction area, neurological symptoms, microcirculation perfusion, and microemboli in microcirculation. OCIDP was characterized based on its extent and distribution, whereas OCCM was measured using RC-rtPA. During ischemia, stroke severity escalation manifested as increasing infarction area, severe neurologic symptoms, and poorer microcirculation perfusion with more microthrombi depositions. OCIDP presented rapid decline following artery occlusion along with a gradual increase in the hypoxic area. Within 3 h following ischemia induction, the ischemic tissue that experienced hypoxia could be rescued, and this reversibility would disappear after 6 h. Within 6 h, OCCM continued to decrease. A significant decrease in oxygen content in cortical venules and cortical parenchyma was observed. These findings assist in establishing the extent of the ischemic penumbra at the microcirculation level and offer a foundation for assessing the ischemic penumbra that could respond positively to reperfusion therapy beyond the typical time window.
研究领域:
神经科学
·
中风
·
微循环
·
氧测量
·
动物模型
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2023
·
IF 6.1
Nuo Duan,Yuting Chang,Wenhui Lv,Changxin Li,Chunxia Lu,Zhouping Wang,Shijia Wu
Herein, a SiO 2 @Ag NPs core/shell nanoparticles were synthesized to fabricate a surface-enhanced Raman spectroscopy (SERS) sensor for the simultaneous determination of histamine (HIS) and tyramine (TYR) based on specific aptamer recognition and ratiometric strategy. SiO 2 @Ag NPs with 4-thiosaminophenol (4-ATP) and Nile blue A (NBA) molecules were used as an internal standard (IS) and labeled with aptamers corresponding to HIS and TYR, respectively. Raman reporter molecules ROX and Cy5 labeled complementary DNA (cDNA) were then hybridized with aptamers to form rigid double-stranded DNA. After the HIS and TYR were captured by their aptamers, resulting in the dissociation of cDNA and separated from the SERS substrate. Therefore, the SERS signal intensity at 1503 cm −1 of ROX and 1358 cm −1 of Cy5 tagged on the terminal of cDNA decreased with the concentration of HIS and TYR increasing, while the SERS signal intensity at 1079 cm −1 of 4-APT and 592 cm −1 of NBA on the substrate remain stable. Thus, the concentrations of HIS and TYR can be determined by the I 1503 /I 1079 and I 1358 /I 592 values, respectively. This sensing strategy achieves a lower detection limit of 0.2 ng/mL for HIS and 0.05 ng/mL for TYR, respectively, demonstrating promising applications in sensitive detection of BAs in animal-derived foodstuff.
研究领域:
分析化学
·
食品科学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Li Ping Cao,Yao Wang,Yan Bai,Yong Jian Jiang,Chun Mei Li,Hua Zuo,Yuan Fang Li,Shu Jun Zhen,Cheng Zhi Huang
Inspired by the specific optical properties of DNA photonic nanowires (PNs) on which fluorescent dyes are to be precisely positioned and photonic energy transfer over nanometers can be achieved, herein, we develop a DNA PN-based homogeneous entropy-driven biomolecular assay (HEBA). Using homogeneous Förster resonance energy transfer (FRET) of Cy3, we constructed a DNA PN capable of transferring energy from the green donor dye (FAM) to the red acceptor fluorophore (Cy5) across a total distance of 10.2 nm with an end-to-end transfer efficiency of 13.2%. By taking DNA PNs as the substrate of entropy-driven circuit, thrombin was detected as a proof-of-principle target. The trigger of HEBA by thrombin, during which separation of Cy3, FAM, and Cy5 occurred and the FRET of the PN got interrupted, resulted in a high value of signal-to-background ratio (S/B, signal and background were FFAM/FCy5 in the presence and absence of thrombin, respectively), giving a detection dynamic range of 5–25 nM with a detection limit of 2.7 nM. This strategy offers an alternative platform for biomarker clinical diagnosis, greatly expanding the application fields of DNA PNs to analytical chemistry.
研究领域:
生物技术
·
分析化学
·
纳米技术
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Siyu Luo,Lin Ma,Fei Tian,Yingqiu Gu,Jingjing Li,Peng Zhang,Guohai Yang,Haitao Li,Lu-Lu Qu
The in situ assay of telomerase activity is important for cancer diagnosis. Herein, a dual-mode functional nanosensor based on fluorescence and surface-enhanced Raman scattering (SERS) was proposed for telomerase activity monitoring. The as-prepared biosensor features Cy5-functional Au nanoparticles (NPs) as the dual functional nanoprobe. The telomerase substrate primer extended under the action of telomerase to form the telomere repeats, and the hairpin DNA loop was opened during hybridization. The distance between the signaling molecule Cy5 and Au NPs changed, resulting in a decrease and a recovery of the SERS and fluorescence signal, respectively. The results showed that the fluorescence and SERS intensity both depended on the telomerase activity and could be used for sensing purposes. On this basis, in situ fluorescence combined with Raman imaging permitted real-time analysis of changes in the telomerase activity of human cells, and hence the approach could be applied for screening of anticancer drugs.
研究领域:
癌症生物学
·
分子生物学
·
纳米技术
·
生物医学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Ying Jiang,Lei Wang,Pengjuan Zhang,Xuehui Liu,Huixia Di,Jie Yang,Shu-Lin Liu,Dai-Wen Pang,Dingbin Liu
Extracellular vesicles (EVs) are intercellular communicators that are heavily implicated in diverse pathological processes. However, it is poorly understood how EVs interact with recipient cells due to the lack of appropriate tracking techniques. Here, we report a robust chemoenzymatic labeling technique for visualizing the internalization process of EVs into target cells in real time. This method uses phospholipase D (PLD) to catalyze the in situ exchange of choline by alkyne in the native EV phosphatidylcholine. Subsequent alkyne–azide click chemistry allows conjugation of Cy5 dyes for visualizing EVs internalization by confocal fluorescence microscopy. The fluorescent labeling of EVs was accomplished in an efficient and biocompatible way, without affecting both the morphology and biological activity of EVs. We applied this chemoenzymatic labeling strategy to monitor the cellular uptake of cancer cell-derived EVs in real time and to further reveal multiple internalization mechanisms. This robust, biocompatible labeling strategy provides an essential tool for EV-related studies ranging from chemical biology to drug delivery.
研究领域:
细胞生物学
·
分子生物学
·
生物技术
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2015
·Vol. 25
·期 5
·1267-1277
·
IF 1.927
Huang Weidong,Wang Yue,Wang Zhimin
Single-molecule detection (SMD) and single-molecule fluorescence resonance energy transfer (smFRET) were conducted using Cy3- and Cy5-labeled single-strand DNAs (ssDNAs) either immobilized on substrates or encapsulated in microdroplets. High-quality fluorescent images were obtained using a total internal reflection fluorescence microscope (TIRFM). In the substrate system, deposition of a low concentration of fluorescence molecules on substrates through electrostatic adsorption showed that most of the fluorescence spots were single molecules, and the mean value of signal to noise ratio (S/N) reached 6.9 ± 0.34. smFRET analysis was conducted through immobilization of donor- and acceptor-labeled oligonucleotides on substrates. In the droplet system, fluorophor-labeled oligonucleotides were injected into T-type microfluidics. Single and double fluorophor-labeled DNA molecules encapsulated in droplets were detected, the FRET efficiency and inter-dye distance of a single donor-acceptor pair were measured accurately. smFRET was conducted detailedly in the tortuous channel for the first time.
研究领域:
生物化学
·
分子生物学
·
生物物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）