BIOSENSORS & BIOELECTRONICS
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2019
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IF 9.518
Lilin Ge,Bin Li,Houxi Xu,Wenyuan Pu,Hang Fai Kwok
A simple and feasible electrochemical immunosensing protocol with glucometer readout was designed for the detection of low-abundance disease-related biomarker (alpha-fetoprotein; AFP) on the basis of backfilling rolling cycle amplification (RCA) with invertase-DNA 2 conjugates on the detection antibody. The assay consisted of the immunoreaction, RCA reaction, DNA 2 -invertase hybridization and glucose measurement. Initially, a sandwiched immunoreaction was carried out between anti-AFP capture antibody-coated microplate between nanogold-labeled pAb 2 detection antibody conjugated with DNA 1 primer (DNA 1 -AuNP-pAb 2 ) in the presence of target ATP . Thereafter, the carried primers triggered the RCA reaction in the presence of circular DNA template, polymerase and dNTP, to produce numerous repeated oligonucleotide sequences for hybridization with many invertase-DNA 2 conjugates. The carried invertase molecules accompanying the hybridization reaction hydrolyzed sucrose into glucose, thereby resulting in the amplification of the detectable signal on a handheld personal glucometer (PGM). Under optimum conditions, the developed immunoassay exhibited high sensitivity for the quantitative screening of AFP within a dynamic range of 0.1–100 ng mL −1 at a low detection limit of 0.087 ng mL −1 . Other biomarkers and proteins did not interfere the signals of this system. In addition, this method was utilized to determine human serum samples containing target AFP, and received well-matched results with the referenced enzyme-linked immunosorbent assay (ELISA) method.
研究领域:
生物技术
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医学诊断
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电化学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
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2024
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IF 5.7
Wei Yang,Liang Feng
Background Surface immobilization of DNA is the foundation of a broad range of applications in biosensing and specific DNA extraction. Polydopamine (PDA) coatings can serve as intermediate layers to immobilize amino- or thiol-labelled molecules, including DNA, onto various materials through Michael addition and/or Schiff base reactions. However, the conjugation efficiency is limited by electrostatic repulsion between negatively charged DNA and PDA. Recently, it has been reported that polyvalent metal ions (such as Mg 2+ and Ca 2+ ) can mediate the adsorption of DNA on PDA surfaces. Inspired by this, in this work we aimed to exploit polyvalent metal ions to facilitate the conjugation of DNA on PDA. Results Mg 2+ was used to promote the conjugation of amino-terminated DNA complementary to ochratoxin A (OTA) aptamer (cDNA-NH 2 ) on PDA-coated magnetic nanoparticles (Fe 3 O 4 @PDA). After the reaction, the unlinked cDNA-NH 2 adsorbed on Fe 3 O 4 @PDA mediated by Mg 2+ was removed with EDTA. In the presence of 20 mM Mg 2+ , the amount of covalently linked cDNA-NH 2 increased approximately 11-fold compared to that in the absence of Mg 2+ . The resulting Fe 3 O 4 @PDA@cDNA conjugates exhibited superior hybridization capacity towards OTA aptamers, minimal nonspecific adsorption, and excellent chemical stability. The conjugates combined with fluorophore-labelled aptamers were employed for OTA detection, achieving a limit of detection (LOD) of 2.77 ng mL −1 . To demonstrate versatility, this conjugation method was extended to Ca 2+ -promoted conjugation of cDNA-NH 2 on Fe 3 O 4 @PDA nanoparticles and Mg 2+ -promoted conjugation of cDNA-NH 2 on PDA-coated 96-well plates. Significance The conjugation efficiency of DNA on PDA was significantly improved with the assistance of polyvalent metal ions (Mg 2+ and Ca 2+ ), providing a facile and efficient method for DNA immobilization. Due to the substrate-independent adhesion property of PDA, this method demonstrates versatility in DNA surface modification and holds great potential for applications in target extraction, biosensing, and other fields.
研究领域:
生物传感
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纳米技术
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分析化学
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材料科学
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DOI
PubMed
高影响因子
JOURNAL OF CONTROLLED RELEASE
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2016
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IF 7.441
Wenjun Zhang,Feihu Wang,Yun Wang,Jining Wang,Yanna Yu,Shengrong Guo,Rongjun Chen,Dejian Zhou
A thiolated pH-responsive DNA conjugated gold nanorod (GNR) was developed as a multifunctional nanocarrier for targeted, pH-and near infrared (NIR) radiation dual-stimuli triggered drug delivery. It was further passivated by a thiolated poly(ethylene glycol)-biotin to improve its cancer targeting ability by specific binding to cancer cell over-expressed biotin receptors. Doxorubicin (DOX), a widely used clinical anticancer drug , was conveniently loaded into nanocarrier by intercalating inside the double-stranded pH-responsive DNAs on the GNR surface to complete the construction of the multifunctional nanomedicine . The nanomedicine can rapidly and effectively release its DOX payload triggered by an acidic pH environment (pH ~ 5) and/or applying an 808 nm NIR laser radiation. Compared to free DOX, the biotin-modified nanomedicine displayed greatly increased cell uptake and significantly reduced drug efflux by model multidrug resistant (MDR) breast cancer cell lines (MCF-7/ADR). The application of NIR radiation further increased the DOX release and facilitated its nuclear accumulation. As a result, this new DNA-GNR based multifunctional nanomedicine exerted greatly increased potency (~ 67 fold) against the MDR cancer cells over free DOX.
研究领域:
纳米技术
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癌症治疗
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药物递送系统
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生物医学工程
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DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2022
·Vol. 10
·期 43
·8931-8944
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IF 7.571
Shengjie Ge,Yujie Wang,Zhiyue Li,Bin Lu,Jinhua Zhu,Hongmei Lu,Xiaowei Cao,Yayun Qian
In this study, we apply catalytic hairpin assembly (CHA) as the signal amplification strategy for the quantification of carcinoembryonic antigen (CEA) and cytokeratin fragment antigen 21-1 (CYFRA21-1) with a surface-enhanced Raman scattering (SERS) microfluidic chip (LoC-SERS) as the carrier. Herein, antibody–DNA conjugates are designed to assist the application of CHA amplification in protein detection. In the presence of protein biomarkers, antibody–DNA conjugates can specifically bind to the target proteins, forming the antigen@antibody–DNA conjugates. The terminal free part of the DNA on the conjugates can trigger the CHA events to connect SERS nanotags to capture nanoprobes. Then, micro-magnet can gather the CHA products in a rectangular chamber, resulting in the aggregation of SERS nanotags, which can ultimately generate abundant “hot spots” for SERS signal enhancement. Using this strategy, CEA and CYFRA21-1 can be successfully determined with a limit of detection (LOD) as low as pg mL−1, much lower than recently reported methods. Meanwhile, a non-small cell lung cancer (NSCLC)-xenografted mouse model was established, and SERS was applied to analyze the expression level of CEA and CYFRA21-1 in tumorigenesis and development. The comparison between SERS results and those of the ELISA method demonstrated a high degree of consistency, suggesting that the proposed CHA-assisted LoC-SERS device has satisfying accuracy. Thus, introducing the CHA strategy via the design of antibody–DNA conjugates opens new gates to ultra-sensitive and specific SERS detection of protein biomarkers.
研究领域:
生物医学工程
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分析化学
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癌症研究
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分子生物学
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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）