Analytical Methods
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2024
·Vol. 16
·期 9
·1330-1340
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IF 2.7
Cuizhong Zhang,Qiang Wang,Chuanze Zhong,Ye Yang,Xuexue Liang,Peican Chen,Liya Zhou
Designing a simple and sensitive photoelectrochemical (PEC) sensor is crucial to addressing the limitations of routine analytical methods. The sensitivity of the PEC sensor, however, relies on the photoelectric material used. In this manuscript, composites of MoS2/rGO (MG) with a large area and layered structure are prepared by simple steps. This material exhibits sensitivity to visible light and demonstrates outstanding photoelectric conversion performance. The constructed PEC aptasensor using this material to detect aflatoxin B1 (AFB1) shows significantly higher sensitivity and stability compared to similar sensors. This may be attributed to the presence of surface defects in MoS2, which provide more active sites for photocatalysis. Additionally, graphene oxide (GO) is reduced to rGO by thiourea and forms a heterojunction with MoS2, enhancing charge carrier separation and interfacial electron transfer. Our research has revealed that the photocurrent intensity of the aptamer electrode decreases with an increase in AFB1 concentration, resulting in a “signal-off” PEC aptasensor. The detection limit of this aptasensor is 2.18 pg mL−1, with a linear range of 0.001 to 100 ng mL−1. This result will also provide a reference for the study of other mycotoxins in food.
研究领域:
食品科学
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生物传感
·
光电化学
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 44
·期 2
·381-386
·
IF 3.069
Qi Wang,Xulu Ma,Houhua Lv,Awen Wei,Tingxuan Wu,Lifeng Ding,Xiang Ma,Chunlei Ma
Ascorbic acid (AA) is an esstential micronutrient in the human body and participates in vital processes. It can only be supplemented by external intake, making the determination of AA in food or beverages of significance. In the present work, MnO2 nanoparticle (MnO2 NP) based turn-off colorimetry was established for AA determination on the basis of AA-stimulated inhibition of catalytic oxidation. MnO2 NPs were synthesized through a biotemplating method and displayed effective catalytic oxidation activity for oxidation of TMB, triggering a chromogenic reaction. Interestingly, the introduction of AA induced the decomposition of MnO2 NPs and as a consequence decreased the colour. Therefore, sensitive and selective turn-off colorimetry for AA detection was established and a satisfactory linear range of 0.5–30 μM with a detection limit of 0.28 μM was obtained. This MnO2 NP-based method was activated via a novel sensing principle, complementing and facilitating colorimetry for AA.
研究领域:
分析化学
·
纳米技术
·
食品科学
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2022
·
IF 9.221
Yihan Wang,Jinfeng Quan,Jialei Zhang,Kejing Huang,Xuemei Wang,Hui Jiang
The fragments of molecular motors can be transported and operated autonomously along a track. Most molecular walker systems are assembled from DNA building modules, exhibiting great potential applications in biocomputing, drug transport, sensing, etc. Hereby, we report a DNA walker driven by endonuclease Nt.BbvC I that can autonomously induce “signal off” sensing platform for highly sensitive detection of tumor cells. DNA density and trajectory conformation can affect DNA walker properties. Molybdenum selenide@gold nanoparticles (MoSe 2 @AuNPs) are modified on the electrode surface as a scaffold to accommodate more hairpin probe (H1) and provide a good interface for DNA walking. Magnetic beads are used to enrich target tumor cells, release single-stranded DNA (S1) and trigger DNA walker-based amplification strategy. Upon addition of tumor cells, more DNA-methylene blue (DNA-MB) is cracked from the electrode surface. Benefiting from efficient electrode modification, magnetic enrichment, DNA walker and enzyme-assisted amplification, an ultra-high sensitivity electrochemical cell analysis is realized, with a detection limit of 2 cells mL −1 . More importantly, this DNA walker strategy is available for tumor cell analysis in clinical samples, suggesting the potential diagnostic applications.
研究领域:
生物传感
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分子生物学
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医学诊断
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DOI
高影响因子
Colloid and Interface Science Communications
·
2021
·
IF 4.914
Weichun Wu,Shenxi Min,Qin Tong,Junhao Wang,Jianghong Hu,Ashish Dhamsaniya,Anamik K. Shah,Vaibhav P. Mehta,Bin Dong,Bo Song
As the third most abundant trace element in human internal environment, Cu 2+ has a significant impact on organisms and ecosystems. The determination of Cu 2+ is an important topic in the field of environmental protection and food safety. In this study, a coumarin-based fluorescent probe (denoted by ICTAB) was designed and synthesized. The results indicate that ICTAB is a “turn-off” fluorescent probe for Cu 2+ , with extremely high selectivity and sensitivity. The limit of detection is down to 0.27 μM. Mass spectroscopy and Job's plot show that ICTAB and Cu 2+ form 2:1 coordinate complexes, and the specific binding sites of Cu 2+ on ICTAB were determined by FTIR and 1 H NMR. More importantly, the fluorescent emission of ICTAB can be repeatedly recovered by removing Cu 2+ with S 2− , which functions as an effective “turn-off” fluorescent probe. ICTAB demonstrated over 89% of recoveries as being applied in detecting Cu 2+ in water.
研究领域:
分析化学
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环境科学
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食品安全
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产品关联
DOI
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2016
·Vol. 14
·期 9
·2684-2690
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IF 3.559
Kui Wang,Jian-Hua Cui,Si-Yang Xing,Hong-Xi Dou
We have successfully implemented the supramolecular tandem assay principle for the real-time, continuous, direct, and label-free monitoring of alkaline phosphatase activity through a fluorescence “switch-off” assay based on a novel calixpyridinium/dye reporter pair. Because several diseases can be preliminarily diagnosed in light of an abnormal level of alkaline phosphatase in serum, the application of tandem assays to selectively monitor alkaline phosphatase activity has feasible implications in disease diagnosis.
研究领域:
生物化学
·
分析化学
·
诊断学
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2014
·
IF 6.451
Gan Qu,Guannan Zhang,Zitong Wu,Aiguo Shen,Jianbo Wang,Jiming Hu
Stable SERS response originating from gold nanoparticles (Au NPs) is demonstrated for the first time to be suitable for detection of heparin with high selectivity . Herein we report a novel “turn-off” SERS assay for heparin based on Raman labelled Au NPs and competitive bonding between heparin and two specialized peptides, such as RKGSGRRLVKC (11-peptide) and CALNN (5-peptide). By means of coordination interactions and other non-electrostatic forces, these 5-peptide capped Au NPs are induced to undergo controllable aggregation upon the additive of 11-peptide and heparin with a concentration range (0–2.4 U/mL), which correspondingly cause quantitative changes of SERS intensity of 4-MBA conjugated on Au NPs. The decreased Raman intensity obtained by subtracting two cases of additives which contain only 11-peptide and the mixture of 11-peptide and heparin, is proportional to the concentration of heparin over a range of 0.2–2.4 U/mL ( R 2 =0.99157), with a limit of detection (LOD) of 0.042 U/mL (S/N=3:1). Moreover, the proposed highly selective method has potential application for rapid, separation-free detection of heparin in human blood serum samples.
研究领域:
分析化学
·
纳米技术
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
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2015
·
IF 4.513
Sihua Chen,Aimin Li,Lizhi Zhang,Jingming Gong
Driven by the urgent demand for the determination of low level perfluorooctanoic acid (PFOA) present in environment, a novel electrochemiluminescence (ECL) sensor has been first developed for the detection of PFOA using the molecularly imprinted polypyrrole modified two-dimensional ultrathin g-C 3 N 4 (utg-C 3 N 4 ) nanosheets as a cathodic ECL emitter with S 2 O 8 2− as coreactant. The prepared molecularly imprinted polymer (MIP) functionalized utg-C 3 N 4 nanosheets (MIP@utg-C 3 N 4 ) exhibit a stable and significantly amplified ECL signal. It is found that the targets of PFOA could be efficiently oxidized by the electro-generated strong oxidants of SO 4 − (from the reduction of coreactant S 2 O 8 2− ), thus leading to a low yield of the excited utg-C 3 N 4 (g-C 3 N 4 *) and finally a decrease in ECL signal. Based on this, a highly sensitive and selective MIP@utg-C 3 N 4 -based signal-off ECL sensor is developed for sensing PFOA. Such a newly designed ECL sensor exhibits highly linear over the PFOA concentration in two ranges, from 0.02 to 40.0 ng mL −1 and 50.0–400.0 ng mL −1 . The detection limit (S/N = 3) is estimated to be 0.01 ng mL −1 (i.e. 0.01 ppb), comparable to the results obtained by using well-established liquid chromatography-tandem mass spectrometry (LC-MS/MS). Toward practical applications, this low-cost and sensitive assay was successfully applied to measure PFOA in real water samples, showing fine applicability for the detection of PFOA in real samples.
研究领域:
分析化学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MODERN OPTICS
·
2023
·
IF 1.3
Sizhong Yi,Yuanhao Huang,Jie Zou,Yuheng Wang,Jiawen Jian,Qinghui Jin,Xiaowei Zhang,Xin Zhang
Recently, metal halide perovskite quantum dots (MHPQDs) have attracted considerable interest in sensing activities due to their excellent optoelectronic properties and high surface activity. Here, aiming for heavy metal detection, we proposed an ultrasensitive turn-off fluorescent probe based on MAPbBr3 MHPQDs for the measurement of copper ions in an organic solvent. A low limit of detection (LOD) of 5.6nM was achieved and the test range was recorded from 0nM to 100nM. In order to achieve this high sensitivity, a thin film layer of electrospun polystyrene(PS) nanofibre was introduced for the structural support of MHPQDs, by which the sensitivity increased two orders of magnitude. The quenching mechanism is also discussed in the paper. We believe the electron transfer effect between Cu2+ and perovskite QDs made the main contribution for turn off sensing in our prototype device.
研究领域:
材料科学
·
分析化学
·
环境科学
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产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2017
·
IF 7.78
Huimei Da,Hongyan Liu,Yingning Zheng,Ruo Yuan,Yaqin Chai
We developed a novel “signal-off” photoelectrochemical (PEC) aptasensor based on an aptamer bridged DNA network structure for the sensitive detection of vascular endothelial growth factor (VEGF 165 ), using g-C 3 N 4 as photoactive material. The DNA network provides an excellent platform for the immobilization of methylene blue (MB), which can facilitate the electron transport through the DNA helix structure and suppress the recombination of electron-hole pairs generated by g-C 3 N 4 . In the presence of the target VEGF 165 , the DNA network can be destroyed adequately by the recognition between VEGF 165 and the aptamer, resulting in the release of MB. Therefore, the originally enhanced electron transfer process could be inhibited, leading to a remarkable decrease of the photocurrent . A good linear relationship between the PEC signal and the logarithm of VEGF 165 concentration over the range of 100 fM to 10 nM with a detection limit of 30 fM can be obtained. Our concept can be easily extended to develop aptasensors for the sensitive detection of different targets by triggering the release of the payloads from their corresponding aptamer bridged DNA networks.
研究领域:
生物化学
·
分析化学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
LUMINESCENCE
·
2020
·Vol. 35
·期 8
·1277-1285
·
IF 1.855
Feifei Zhao,Tianyi Zhang,Yu Yang,Changli Lü
Carbon dots (CDs) have drawn increasing interests due to their unique optical properties and promising application in various fields. In this study, citric acid (CA) and 5-chloromethyl-8-hydroxyquinoline (LQ) were used to synthesize nitrogen-doped CDs as novel fluorescent probes using a one-step solvothermal route. The as-prepared CDs had strong blue-white fluorescence emission when excited at 405 nm wavelength with a quantum yield (QY) of 25%, behaving with high ion concentration stability. Water-soluble CDs with a 8-hydroxyquinoline structure on their surface could be used to detect Al 3+ using a ‘turn on’ mechanism and trinitrophenol (TNP) using a ‘turn off’ mechanism with detection limits of 229 nM and 44.4 nM, respectively. Al 3+ enhances the fluorescence of CDs by forming a coordination complex to generate a fluorescence synergistic role and limit CD nonradiative transition. TNP quenched the fluorescence with high selectivity and sensitivity, which was attributed to the inner filter effect and static quenching. These results indicated that these CDs with their unique ‘turn on’ and ‘turn off’ nature have potential application in the environmental protection field and in prevention of terrorist threats.
研究领域:
材料科学
·
分析化学
·
环境科学
·
纳米技术
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Xiao-Lei Zhang,Xue Li,Xiao-Tong Li,Ye Gao,Fang Feng,Gong-Jun Yang
The Au nanoclusters@graphene quantum dots nanocomposite as an electrochemiluminescence (ECL) luminophore was synthesized through amide coupling reaction between Au nanoclusters (Au NCs) and graphene quantum dots (GQDs). The ECL intensity of the as-prepared Au NCs@GQDs was enhanced for 2.6-fold compared with that of Au NCs or 40-fold compared with that of GQDs, which was due to the ECL resonance energy transfer between GQDs as a donor and Au NCs as an acceptor, and excellent electrical conductivity of GQDs. In addition, the synergistic effect likewise improved stability of the ECL signal. A type of “signal-off” solid-state ECL sensor for detection of pentoxifylline was fabricated based on the selective quenching effect of pentoxifylline on the ECL signal of Au NCs@GQDs in alkaline medium. The sensor showed excellent sensitivity and wide linearity for pentoxifylline determination in the range from 7.0 × 10 −7 to 1.2 × 10 -4 mol/L with the detection limit of 9.0 × 10 -8 mol/L (S/N = 3). The proposed method was successfully applied for pentoxifylline detection in pharmaceutical tablet with satisfactory results.
研究领域:
分析化学
·
纳米技术
·
药物分析
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Long Zhao,Tao Wang,Qiang Wu,Yuan Liu,Zhoujiang Chen,Xiaohong Li
“Turn-on” or “turn-off” probes remain challenges in the establishment of sensitive, easily operated, and reliable methods for in situ monitoring bioactive substances. In the current study, electrospun fibrous strips are designed to provide straightforward observations of ratiometric color changes with the naked eye in the presence of serum heparin or urine trypsin. A tetraphenylethene (TPE) derivative is constructed and along with phloxine B is grafted on fibers, followed by protamine adsorption to induce static quenching of phloxine B and aggregation-induced emission of the TPE derivative. The presence of heparin or trypsin removes protamine to restore the fluorescence of phloxine B at 574 nm (I574) and relieve the emission of the TPE derivative at 472 nm (I472). The grafting densities of phloxine B and the TPE derivative are essential to achieve the optimal fluorescence-intensity ratio of I574/I472 for the ratiometric detection of heparin and trypsin. Under illumination by an ultraviolet lamp, the fibrous mats turn from cyan to green in the presence of heparin at 0.4 U/mL and to a bright yellow at 0.8 U/mL, which is feasible in sensing serum heparin levels during postoperative and long-term care of patients after cardiovascular surgery. The protamine digestion results in similar color transitions with increasing trypsin levels up to 8 μg/mL, indicating the potential for monitoring urine trypsin levels of pancreas transplant patients. The color strips based on the ratiometric fluorescent response indicate advantages in lowering the detection limit and improving the accuracy and reproducibility, bearing great potential for a real-time and naked-eye detection of bioactive substances as self-test devices.
研究领域:
生物医学工程
·
分析化学
·
材料科学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
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