ANALYST
·
2022
·Vol. 147
·期 11
·2575-2581
·
IF 5.227
Xu-Hua Zhao,Xiao-Chun Dai,Ya-Nan Zhou,Han-Xiao Zhang,Xiao-Hua Cui,Xiang Zhai,Bao-Feng Yu,Zhi-Ling Song
In this paper, we developed an amplified fluorescence biosensor for acetylcholinesterase (AChE) activity detection by taking advantage of the mercury ion-mediated Mgzyme (Mg2+-dependent DNAzyme) activity. The catalytic activity of Mgzyme can be inhibited by the formation of T–Hg2+–T base pairs between the Mgzyme and mercury ions. Therefore, the Mgzyme–Hg2+ complex has no activity on a molecular beacon (MB) substrate, which afforded a very weak fluorescence background for this biosensor. After the addition of acetylcholinesterase (AChE), the substrate acetylthiocholine could be hydrolyzed to thiocholine, which has a stronger binding power with mercury ions than T–Hg2+–T base pairs. Therefore, the Mgzyme activity was recovered. The activated Mgzyme could hybridize with the MB substrate and undergo many cleavage cycles, resulting in a significant increase of fluorescence intensity. This biosensor displayed high sensitivity with the detection limit as low as 0.01 mU mL−1. Moreover, this design did not require complex composition and sequence design; thus it is simple and convenient. This biosensor was also applied for the determination of AChE in human blood and showed satisfactory results.
研究领域:
分析化学
·
生物化学
·
生物传感器
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2021
·Vol. 13
·期 35
·4001-4007
·
IF 2.896
Mengyang Zhou,Chao Li,Baolong Wang,Lin Huang
Exosomes as fluid biomarkers hold great promise for noninvasive cancer diagnosis. However, a method for the rapid and convenient detection of exosomes is still a challenge because current analysis processes involve multiple steps and yield low sensitivity. Here, we developed a wash-free fluorescent biosensor for the rapid and sensitive quantification of exosomes by combining aptamer and nicking endonuclease (Nb·BbvCI). In this system, an aptamer–trigger complex was used as the recognition element; the trigger probe could be released, and it hybridized with gold nanoparticles (GNPs)–DNA–FAM conjugates, thereby resulting in Nb·BbvCI-assisted target recycling. As a result, our method allowed the quantification of exosomes with lower analysis time by using a cocktail containing an aptamer–trigger complex, Nb·BbvCI, and GNPs–DNA–FAM. A high sensitivity with a limit of detection (LOD) of 1.0 × 104 particles per μL could be achieved. Besides, this biosensor exhibited potential application for the quantification of exosomes in human plasma, facilitating the development of exosome-based noninvasive cancer diagnosis.
研究领域:
分子生物学
·
医学诊断
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2019
·Vol. 12
·期 2
·188-192
·
IF 2.378
Yanling Huang,Guiyin Yue,Fang Luo,Longhua Guo,Bin Qiu,Zhenyu Lin
Hydrogen sulfide (H2S) is a dramatically toxic gas molecule; long term exposure to H2S environment poses a serious threat to human health. It is highly imperative to develop sensitive and selective methods for H2S detection. In this study, a signal-on fluorescence biosensor for the H2S (used to represent the total amount of H2S, HS− and S2−) detection was developed based on silver-mediated base pairs (C–Ag+–C). Two separate C-rich single-stranded DNAs (ssDNAs) were synthesized, namely, one was labeled with fluorescein (6-carboxyfluorescein, FAM) and the other was labeled with quencher (black hole quencher, BHQ1). The two ssDNAs were in a flexible single strand owing to the mismatch of the ssDNA, and hence, significant fluorescence intensity was observed. In the presence of Ag+, DNA probes could selectively capture Ag+ to form double stranded DNA (dsDNA) via the C–Ag+–C base pairs, which made the quench of FAM by BHQ1 and low fluorescence signal was detected. With the addition of H2S to the system, the dsDNA was decomposed into ssDNA since Ag+ could be released from C–Ag+–C by the formation of a more stable complex Ag2S, which resulted in the recovery of the fluorescence intensity. The enhanced fluorescence intensity had a linear relationship with H2S concentration in the range from 0.5 to 20 μM with a detection limit (LOD) of 0.16 μM (S/N = 3). The proposed system was applied to detect H2S (used to represent the total amount of H2S, HS− and S2−) in air near a garbage station with satisfying results.
研究领域:
环境科学
·
分析化学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2017
·
IF 4.162
Zhonghui Chen,Mi Sun,Fang Luo,Kefeng Xu,Zhenyu Lin,Lan Zhang
In most aptamer based stimulus response mesoporous silica nanoparticles (MSN) systems, the aptamer is modified on the MSN via electrostatic interaction , however leakage might exist after a certain time in the system and hence the stability is not good. In this study, the pores of MSN were capped by aptamer through click chemistry reaction for the first time and the system was then employed to develop a fluorescence biosensor. Specifically, the aptamer of the target (thrombin in this study) was hybridized with its complementary DNA (which was initially modified with alkyne at the terminal) to form a double strand DNA (dsDNA) firstly, and then this dsDNA was modified on N 3 modified MSN via Cu(I) catalyzed alkyne-azide cycloaddition reaction. The guest molecules (fluorescein) were blocked in the pores of the MSN with high efficiency and nearly no leakage was detected. Upon the introduction of thrombin, thrombin specifically recognized its aptamer, so aptamer released from the MSN; and the single strand DNA(ssDNA) left could not cap the pores of the MSN efficiently and hence caused the releasing of fluorescein into the solution. The enhanced fluorescence intensity of the system has a good linear relationship with the thrombin concentration in the range of 50–1000 ng mL −1 with a detection limit of 28.46 ng mL −1 . The proposed biosensor has been successfully applied to detect thrombin in serum samples with high selectivity . The same strategy can be applied to develop biosensors for different targets by changing the adopted aptamer.
研究领域:
纳米技术
·
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2020
·Vol. 145
·期 13
·4664-4670
·
IF 3.978
Zhifang Wu,Hui Zhou,Qianjin Han,Xuelian Lin,Dongxue Han,Xun Li
The efficient detection of illicit drugs such as cocaine continues to be important for the fight against drug trafficking. Herein, we report a one-step method for rapid and specific cocaine detection. The method is based on our finding that small-molecule Thioflavin T (ThT) can act as a fluorescence indicator, which can be bonded with the anti-cocaine aptamer (MNS-4.1) to generate an enhanced fluorescence signal. More interestingly, upon cocaine binding, the intercalated ThT can be replaced, causing a drastic fluorescence reduction. We further optimized the sequence of MNS-4.1 and a new anti-cocaine aptamer (coc.ap2-GC) was obtained. This aptamer showed a higher affinity to both ligands, which increased the ThT binding fluorescence intensity and showed the highest quenching efficiency. Based on the fluorescence change induced by competitive binding, cocaine detection could be accomplished by a “mix-and-detect” strategy within seconds. Such a label-free method exhibits high sensitivity to cocaine with a low detection limit of 250 nM. Moreover, the practical sample analysis (2.5% human urine and saliva) also exhibits good precision and high sensitivity.
研究领域:
分析化学
·
毒品检测
·
生物传感器
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2024
·Vol. 191
·期 7
·1-12
·
IF 5.3
Tao Chunxu,Wang Junyan,Zhu Ying,Ding Chao,Shen Zhuoyue,Sun Danni,Cao Shanshan,Jiang Xinrong,Li Yaqi,Liu Chang,Zhang Qi,Li Shijie,Zhang Xinyan,Shi Qiaoqiao,Kong Dezhao
A fluorescence biosensor for determination of aflatoxin B 1 (AFB 1 ) based on polydiacetylene (PDA) liposomes and exonuclease III (EXO III)-assisted recycling amplification was developed. The AFB 1 aptamer partially hybridizes with complementary DNA (cDNA), which is released upon recognition of AFB 1 by the aptamer. Subsequently, the cDNA hybridizes with hairpin H to form double-stranded DNA that undergoes digestion by EXO III, resulting in the cyclic release of cDNA and generation of capture DNA for further reaction. The capture DNA then hybridizes with probe modified on PDA liposomes, leading to aggregation of liposomes and subsequent fluorescence production. This strategy exhibited a limit of detection of 0.18 ng/mL within the linear range 1–100 ng/mL with a determination coefficient > 0.99. The recovery ranged from 92.81 to 106.45%, with relative standard deviations (RSD) between 1.73 and 4.26%, for corn, brown rice, peanut butter, and wheat samples. The stability, accuracy, and specificity of the method demonstrated the applicability for real sample analysis. Graphical abstract
研究领域:
食品科学
·
分析化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Xiuzhong Wang,Ting Hou,Shanshan Dong,Xiaojuan Liu,Feng Li
Pesticides are of great importance in agricultural and biological fields, but pesticide residues may harm the environment and human health. A highly sensitive fluorescent biosensor for the detection of carbamate pesticide has been developed based on acetylcholinesterase (AChE)-catalyzed hydrolysis product triggered Hg 2+ release coupled with subsequent nicking enzyme-induced cleavage of a duplex DNA for cycling amplification. In this protocol, two DNA probes, an unmodified single-stranded helper DNA probe 1 (HP1) and a quencher–fluorophore probe (QFP) are ingeniously designed. HP1 can be folded into hairpin configuration through T–Hg 2+ –T base pair formation. QFP, labeled with FAM and BHQ1 at its two terminals, contains the recognition sequence and the cleavage site of the nicking enzyme . In the presence of carbamate pesticide, the activity of AChE is inhibited, and the amount of the product containing the thiol group generated by the hydrolysis reaction of acetylthiocholine chloride (ACh) decreases, resulting in the release of a low concentration of Hg 2+ . The number of HP1 that can be selectively unfolded would be reduced and the subsequent nicking enzyme-assisted cleavage processes would be affected, resulting in decreased fluorescence signals. The fluorescence intensity further decreases with the increase of the pesticide concentration. Therefore, the pesticide content can be easily obtained by monitoring the fluorescence signal change, which is inversely proportional to the logarithm of the pesticide concentration. The detection limit of aldicarb , the model analyte , is 3.3 μg L −1 , which is much lower than the Chinese National Standards or those previously reported. The as-proposed method has also been applied to detect carbamate pesticide residues in fresh ginger and artificial lake water samples with satisfactory results, which demonstrates that the method has great potential for practical application in biological or food safety field.
研究领域:
分析化学
·
环境科学
·
食品安全
✓ 已验证
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2025
·
IF 10.5
Yuqing Zhang,Chunli Yang,Jiayang He,Zhihan Zhang,Yaqin Chai,Ruo Yuan,Wenju Xu
It might be intriguing and desirable to explore the stimuli-responsive modulation of dynamic switching circuit (DSC) for constructing versatile fluorescence biosensors via two-step sequential independent displacement reactions. Here, a switchable DNA translator (DT) encoding three functional modules is proposed to implement DSC for interpreting specific Key triggers (i.e. DNA segment, miRNA or small molecule) by activating intramolecular conformation transition. Upon presenting Key to regulate strand displacement, the Lock -blocked DT is liberated and self-folded into “active” on-state hairpin structure, so that two ended toeholds are oriented closely to execute proximal hybridization cooperatively for Key -responsive signal readout. Benefited from fast kinetics, efficient transduction, simplified operation and flexible programming, the Key -actuated DSC strategy achieved label-free assay of various target species by employing tunable Ag nanocluster as fluorescent reporter adjacent to or away from hemin/G-quadruplex complexes, which would be more potential and applicable in versatile fluorescence biosensors, identifiable cell imaging or customized tasks than typical strand displacements.
研究领域:
生物化学
·
分子生物学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2025
·
IF 3.1
Fang Fang,Cao Hongyu,Lu Jialu,Chen Nannan,Zhang Lu,Chen Yang
Carbon dots (CDs)-based ratiometric fluorescence strategies have attracted considerable attention. In this study, we developed a facile ratiometric fluorescent biosensor for DNA detection by utilizing the blue-emitting carbon dots (BCDs) as the fluorophore and acriflavine (AF), a fluorescent biological stain reagent, as both the response and recognition molecules. When AF was added, the fluorescence of BCDs decreased effectively and accompanied by a hypsochromic shift from 448 to 425 nm, whereas the fluorescence of AF at about 500 nm appeared due to the synergistic effect of Förster resonance energy transfer (FRET) and the inner filter effect (IFE) between the BCDs and AF. In the presence of DNA, the intercalative binding of AF into the DNA helix resulted in the fluorescence quenching of AF and the fluorescence restoration of BCDs at the same time. Therefore, the quantitative detection of DNA can be carried out vis evaluating the fluorescence intensity ratio of F 425 /F 500 . Under optimized conditions, the developed fluorescence method had an excellent linear range from 0 to 90 µM and a low detection limit of 0.52 µM. In addition, satisfactory results were obtained for the analysis of DNA in synthetic and real samples, with spiked recoveries ranging from 90.1 to 101.3%, demonstrating the enormous potential of the developed sensing platform for bioanalysis and biodetection. Graphical
研究领域:
生物传感器
·
分析化学
·
纳米技术
·
生物分析
·
荧光光谱
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2012
·
IF 4.525
Ali Cao,Yanli Tang,Yue Liu
A new fluorescent biosensor has been designed to screen α-glucosidase inhibitors (AGIs) sensitively by utilizing signal amplification effect of conjugated polymers. The fluorescence of cationic poly(fluorenylene phenylene) (PFP) was quenched in the presence of para-nitrophenyl-α-d-glucopyranoside and α-glucosidase, and turned on upon addition of AGIs. Thus, a new method was developed for AGIs screening based on the fluorescence turn-off/turn-on. The IC50 values obtained for inhibitors were compared with that reported using absorption spectroscopy. All results present the new method is more sensitive and promising in screening AGIs and inhibitors of other enzymes whose hydrolysis product is 4-nitrophenol.
研究领域:
生物化学
·
药物开发
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Jing Li,Minhui Chen,Qi Jiang,Wei Zhang,Yiting Lan,Md. Maruf Ahmed,Cheng Ma,Jin Huang,Qin Xu
To tackle the predicament of the traditional turn-off mechanism, exploring an activated turn-on system remains an intriguing and crucial objective in biosensing fields. Herein, a dark DNA Ag nanocluster (NC) with hairpin-structured DNA containing a six-base cytosine loop (6C loop) as a template is atypically synthesized. Intriguingly, the dark DNA Ag NCs can be lit to display strong red-emission nanoclusters. Building upon these exciting findings, an unprecedented and upgraded turn-on biosensing system [entropy-driven catalysis circuit (EDCC)-Ag NCs/graphene oxide (GO)] has been created, which employs an EDCC to precisely manipulate the conformational transition of DNA Ag NCs on the GO surface from adsorption to desorption. Benefiting from the effective quenching of GO and signal amplification capability of the EDCC, the newly developed EDCC–Ag NCs/GO biosensing system displays a high signal-to-background (S/B) ratio (26-fold) and sensitivity (limit of detection as low as 0.4 pM). Meanwhile, it has good specificity, excellent stability, and reliability in both buffer and biological samples. To the best of our knowledge, it is the first example that adopts an EDCC to precisely modulate the configuration transformation of DNA Ag NCs on the GO surface to obtain a biosensor with low background, strong fluorescence, high contrast, and sensitivity. This exciting finding may provide a new route to fabricate a novel turn-on biosensor based on hairpin-templated DNA Ag NCs in the optical imaging and bioanalytical fields.
研究领域:
生物传感
·
分子生物学
·
纳米技术
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2020
·
IF 10.257
Ziqi Zhou,Yangzi Zhang,Mingzhang Guo,Kunlun Huang,Wentao Xu
A relatively-simple and high-efficient fluorescent magnetic biosensor based on DNAzyme was established for the detection of E. coli O157:H7. In order to solve the problem of weak signal and low sensitivity in the detection of foodborne pathogenic bacteria , we ingeniously designed a fluorescent sensor based on triple signal amplification of magnetic beads, DNAzyme and photoluminescence . In the detection process, the E. coli -specific RNA-cleaving DNAzyme can specifically identify the target protein in crude intracellular mixture (CIM), which caused its conformation changes and induced rolling circle amplification (RCA) to the generation and luminescence of copper nanoclusters (CuNCs). This cascade amplification design can capture weak signals in the sample. The biosensor also indicated a good linear range from 10 CFU mL −1 to 1000 CFU mL −1 and obtained a limit of detection (LOD) of 1.57 CFU mL −1 , which showed a relatively high sensitivity compared with other studies. Furthermore, the biosensor displayed high-efficient detection capability in 1.5 h and good reproducibility (relative standard deviations < 2%). It has been proved that this sensor is feasible to the detection of E. coli O157:H7 in drinking water and apple juice. Moreover, we found that the final detection product can effectively wrap the magnetic beads and can be driven by the magnetic field. And this unexpected discovery will provide ideas for the development of biosensing robots.
研究领域:
生物化学
·
食品科学
·
分子生物学
✓ 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）