ANALYTICA CHIMICA ACTA
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2013
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IF 4.387
Ying Chen,Mengli Yang,Yun Xiang,Ruo Yuan,Yaqin Chai
Single nucleotide polymorphisms are the most common type of genetic variations among human beings and can serve as biomarkers for various types of diseases. In this work, based on ligase chain reaction amplification for the production of massive hemin/G-quadruplex DNAzymes to quench the electrochemiluminescent (ECL) emission of quantum dots (QDs), a universal and sensitive single nucleotide polymorphism detection method is described. During the ligase chain reaction process, the mutant K-ras target gene is recycled and exponentially duplicated, leading to the attachment of numerous G-rich sequences on the QD-embedded sensing surface. Upon the addition of the assistant sequences and hemin, numerous hemin/G-quadruplex DNAzymes are formed, which consume the dissolved oxygen in the detection buffer and result in significant quenching of QD ECL emission for sensitive single nucleotide polymorphism determination. The developed method shows a linear range of 50 fM to 50 pM and an estimated detection limit of 45 fM for the mutant K-ras gene. The proposed strategy also exhibits high selectivity towards the mutant K-ras gene against the co-existence of 10 3 -fold excess of the wild-type K-ras gene, which makes our method a useful addition to the alternatives for single nucleotide polymorphism monitoring.
研究领域:
分子生物学
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医学诊断
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生物传感技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOELECTROCHEMISTRY
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2024
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IF 4.8
Haotian Xie,Zhaojiang Yin,Guobin Wei,Binghui Li,Hanfeng Cui,Hao Fan,Jing Zhang
This study developed a dual-mode “on-off-on” sensor based on a bipyridine ruthenium metal–organic framework (Ru-MOF) and dual enzyme cleavage technology for the sensitive detection of the K-ras gene. The sensor combines electrogenerated chemiluminescence (ECL) and fluorescence (FL) detection modes, achieving high sensitivity and specificity in detecting the K-ras gene through catalytic hairpin assembly (CHA) and dual enzyme cleavage reactions. Experimental results showed that the detection limits for the K-ras gene were 0.044 fM (ECL) and 0.16 fM (FL), demonstrating excellent selectivity and stability during detection. Through testing actual samples, the sensor has shown potential for application in complex biological environments. This method offers an efficient and reliable new tool for cancer diagnosis and treatment.
研究领域:
生物传感
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分子诊断
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癌症研究
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL BIOCHEMISTRY
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2014
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IF 2.305
Xian Fang,Lijuan Bai,Xiaowei Han,Jiao Wang,Anqi Shi,Yuzhong Zhang
In this study, an ultra-sensitive hairpin DNA-based electrochemical DNA biosensor for K-ras gene detection is described. Gold nanoparticles (Au-NPs) and horseradish peroxidase (HRP)–streptavidin capped Au-NPs (HAS) conjugates are used for signal amplification. Initially, hairpin DNA dually labeled with thiol at its 5′ end and with biotin at its 3′ end is immobilized on the surface of Au-NPs modified electrode , and the hairpin DNA is in a “closed” state; hence, the HAS conjugates are shielded from being approached by the biotin due to steric hindrance . However, in the presence of target DNA, the target DNA hybridizes with the loop structure of hairpin DNA and causes conformational change, resulting in biotin forced away from the electrode surface, thereby becoming accessible for the HAS conjugates. Thus, the HAS conjugates are linked to the electrode surface via the specific interaction between biotin and streptavidin . Electrochemical detection was performed in phosphate-buffered saline (PBS) containing tetramethylbenzidine (TMB) and H 2 O 2 . Under optimal conditions, the peak current differences (Δ I ) are linear with the target DNA in the range from 0.1 fM to 1 nM with a detection limit of 0.035 fM. Furthermore, this biosensor also demonstrates its excellent specificity for single-base mismatched DNA.
研究领域:
生物化学
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分子生物学
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纳米技术
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基因工程
✓ 已验证
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
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2023
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IF 12.6
Longshua Qin,Ting Huang,Hanfeng Cui,Mengqing Cheng,Guobing Wei,Fusheng Liao,Wei Xiong,Hedong Jiang,Jing Zhang,Hao Fan
Herein, an fluorescence (FL)−electrochemiluminescence (ECL) dual-mode biosensor is constructed based on the dual-signal “turn-on” strategy of functionalized metal-organic frameworks nanosheets (RuMOFNSs)-tetraferrocene for K-ras gene detection, and the mechanism of bursting through front-line orbital theory is explained for the first time. Amino-functionalized tetraferrocene-labeled probe DNA molecules are linked to RuMOFNSs by covalent amide bonds, acting as FL and ECL intensity switches. The target DNA, complementary to the probe DNA, triggers cyclic amplification of the target by nucleic acid exonuclease III (Exo III), repelling tetraferrocene reporter groups away from RuMOFNSs and inhibiting the electron transfer process and photoinduced electron transfer (PET) effect. These phenomena induce a double turn-on of FL and ECL signals with a high signal-to-noise ratio. The developed FL-ECL dual-mode sensing platform provides sensitive detection of the K-ras gene with detection limits of 0.01 fM (the detection range is 1 fM to 1 nM) and 0.003 fM (the detection range is 0.01 fM to 10 pM), respectively. In addition, the proposed dual-mode sensor can be easily extended to detect other disease-related biomarkers by changing the specific target and probe base sequences , depicting potential applications in bioanalysis and early disease diagnosis.
研究领域:
生物化学
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分析化学
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生物技术
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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