Nanoscale
·
2015
·Vol. 8
·期 16
·8553-8558
·
IF 7.394
Lin Fan,Yanyan Tian,Rong Yin,Doudou Lou,Xizhi Zhang,Meng Wang,Ming Ma,Shouhua Luo,Suyi Li,Ning Gu,Yu Zhang
Conventional immunohistochemistry is limited to subjective judgment based on human experience and thus it is clinically required to develop a quantitative immunohistochemical detection. 3,3′-Diaminobenzidin (DAB) aggregates, a type of staining product formed by conventional immunohistochemistry, were found to have a special optical property of dark-field imaging for the first time, and the mechanism was explored. On this basis, a novel immunohistochemical method based on dark-field imaging for detecting HER2 overexpressed in breast cancer was established, and the quantitative analysis standard and relevant software for measuring the scattering intensity was developed. In order to achieve a more sensitive detection, the HRP (horseradish peroxidase)-labeled secondary antibodies conjugated gold nanoparticles were constructed as nanoprobes to load more HRP enzymes, resulting in an enhanced DAB deposition as a dark-field label. Simultaneously, gold nanoparticles also act as a synergistically enhanced agent due to their mimicry of enzyme catalysis and dark-field scattering properties.
研究领域:
医学影像
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癌症研究
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生物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Xianrui Chen,Zhipeng Gao,Tingting Long,Jianhua Xie,Xiujiang Li,Zhibing Huang
Conventional immunochromatographic test strips (ICSs) based on gold nanoparticle (AuNP) probes offer limited sensitivity. Here, AuNPs were separately labeled with monoclonal or secondary antibodies (MAb or SAb). In addition, spherical, homogeneously dispersed, and stable selenium nanoparticles (SeNPs) were also synthesized. By optimizing the preparation parameters, two ICSs based on the dual AuNP signal amplification (Duo-ICS) or SeNPs (Se-ICS) were developed for the rapid detection of T-2 mycotoxin. The detection sensitivities of the Duo-ICS and Se-ICS assays for T-2 were 1 ng/mL and 0.25 ng/mL, respectively, which were 3-fold and 15-fold more sensitive, respectively, than a conventional ICS. Furthermore, the ICSs were applied in the detection of T-2 in cereals, which requires higher sensitivity. Our findings indicate that both ICS systems can be used for rapid, sensitive, and specific detection of T-2 toxin in cereals and potentially other sample types.
研究领域:
分析化学
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毒理学
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食品科学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
Results in Chemistry
·
2021
·
IF 0
Guangxin Yang,Chunhao Wei,Yunyu Tang,Jingru Zhang,Xuan Zhang,Hai Chi,Leren Tao,Cong Kong
A novel and sensitive fluorescence immunoassay was developed for the determination of Vibrio parahaemolyticus (VP) based on gold nanoclusters (BSA-AuNCs). The assay signal was originated from inner filter effect (IFE) between BSA-AuNCs and p-nitrophenol (PNP). A double emission peak fluorescent gold nanocluster with good property was quickly synthesized, which was used as fluorescent probe in this method. To achieve the IFE, Alkaline phosphatase labeled second antibody (IgG-ALP), which could generate PNP with the substrate of PNPP (p-nitrophenyl phosphate), was used in the immune reaction. According the competitive reaction, VP could be detected indirectly by the change of fluorescence signal. Under the optimal conditions, the limit of detection (LOD) for VP was 5 × 10 2 CFU/mL. The linear detection range was 10 3 -10 7 CFU/mL. Furthermore, the proposed method was successfully applied to detect VP in real samples, giving recoveries in the range of 82.5%–113.0%, and the coefficient of variation was 5.46%–9.88%.
研究领域:
分析化学
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微生物学
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食品安全
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产品关联
DOI
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 10
·1-9
·
IF 6.232
Huang Lingting,Wang Jun,Wang Qingshui,Tang Dianping,Lin Yao
A paper-based visual fluorescence immunoassay is presented for the detection of matrix metalloproteinase-7 (MMP7) that is related to renal cancer. The method is based on the distance-dependent fluorescence quenching of CdTe quantum dots (QDs) on a nitrocellulose membrane by Ag + following a sandwich-type immunoreaction on microtiter wells using silver nanoparticle (AgNP)–labeled secondary antibody– and primary antibody–coated microtiter wells. The silver nanoparticles captured in the well are dissolved with HNO 3 , while the quenching effect of QDs is based on silver ion-exchange reaction under 365-nm excitation light irradiation. Increasing concentration of released Ag + , thus higher concentration of the protein, leads to an increased distance of quenching on the nitrocellulose membrane. The paper-based immunoassay by combination of AgNP-assisted ion-exchange reaction with QD gives good distance-dependent responses and allows the detection of MMP7 at a concentration as low as 7.3 pg mL −1 . The coefficients of variation are less than 6.9% and 12.4% for intra-assay and inter-assay, respectively. High specificity and long-term stability are achieved during the assay. Importantly, the testing of human serum samples using our strategy shows well-matched results with commercial human MMP7 ELISA kits.
A distance-dependent visual immunoassay is developed for the determination of serum matrix metalloproteinase-7 on CdTe quantum dot–impregnated paper with silver ion-exchange reaction.
研究领域:
分析化学
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生物化学
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医学诊断
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纳米技术
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 21
·5437-5444
·
IF 3.286
Jiao Xiangyu,Zhou Yabin,Zhao Dan,Pang Duo,Wang Changtao,Du Hongwu,Wen Yongqiang,Zhang Xueji
To meet the need for high-throughput immunoassays, many multiplex fluorescent immunoassays have been proposed. Most of them need different kinds of fluorescent label indicators during the test. In this work, a novel indirect ELISA-inspired dual-channel fluorescent immunoassay based on 3-mercaptopropionic acid capped CdTe/ZnS quantum dots (QDs) was constructed. The ELISA wells were coated with two kinds of antigen–QD complex. When the primary antibodies were present in a sample, they mediated the binding of a secondary antibody–DNA–gold nanoparticle complex to the antigen–QD complex. Then the gold nanoparticles quenched the fluorescence of the QDs and a decrease in fluorescence intensity was observed. Thus, the amount of primary antibody could be estimated from the decrease of fluorescence intensity. Owing to the wide absorption range and the relatively narrow emission band of the QDs, the dual-channel fluorescent immunoassay system could work at the same excitation wavelength and the emission wavelengths of each channel had no interference. As a result, two different kinds of primary antibody could be detected at the same time in one ELISA well, which simplified the operation and greatly improved the efficiency. Besides, only one type of secondary antibody needs to be added to the prepared microtiter plates, which further simplified the operation during the detection procedure. This dual-channel fluorescent immunoassay system will provide new insights into high-throughput immunodetection.
Graphical abstract
研究领域:
生物化学
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分析化学
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纳米技术
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免疫学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Yan-Fei He,Kai Cheng,Zi-Tao Zhong,Xiao-Lin Hou,Chang-Zhi An,Wei Chen,Bo Liu,Yuan-Di Zhao
A method for simultaneous labeling and multicolor fluorescence imaging of different hepatic immune cells below freezing point is established based on quantum dots . In the experiment, carbon quantum dots with emission wavelength of 435 nm, [email protected] quantum dots at 542 nm and [email protected] quantum dots at 604 nm are synthesized respectively, it is found that when the mass fractions of KCl (as antifreeze) are 12 %, 14 %, and 12 %, respectively, the three quantum dot dispersion systems remain liquid state at −20 °C. After they are conjugated with the corresponding secondary antibodies, agarose gel electrophoresis , circular dichroism and capillary electrophoresis confirm the effectiveness of conjugation. By indirect immunofluorescence method, the above three quantum dot fluorescent probes are used to simultaneously and specifically target a variety of liver immune cells, and the multi-color simultaneous imaging of different liver immune cells is realized under the same excitation wavelength, it is found that hepatic macrophages are arranged radially in the liver, hepatic stellate cells present punctate distribution, and hepatic sinusoidal endothelial cells present circular distribution, which is consistent with the results of H&E staining and ultrathin section TEM. This study provides an important technical means for elucidating the structure and function of the liver.
研究领域:
免疫学
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生物技术
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细胞生物学
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材料科学
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产品关联
DOI
PubMed
高影响因子
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