Nanoscience and Nanotechnology Letters
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2019
·Vol. 11
·期 8
·1104-1115
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IF 0
Bhatti Huma,Jawed Rohil,Liu Hang,Ali Irshad,Zhu Libo,Liu Quanjun
Biological nanopores have been proved as impressive nano-devices capable of holding the detection sensitivity from a nanoparticle to a single macromolecule. Protein pores are efficiently reproducible with assured channel geometry and their propensity to be engineered easily make them
convenient in nanopore sensing techniques. Among various porin-proteins, MspA porin of Mycobacterium smegmatis is quite ideal for nanopore DNA sequencing. However, the traversing speed of singlestranded DNA (ssDNA) through both the mutants of MspA (M1MspA and M2MspA) is too fast to
be analyzed. Therefore, we utilized a new mutant of MspA, termed as M3MspA which was previously purified in our laboratory. We, for the first time, demonstrated that translocation of ssDNA is achieved at a minimum voltage-threshold of 40 mV at pH 8.0. This new mutant of MspA exhibits a crystal-clear
discrimination between two homopolymers, poly dA50 and poly dC50 with duration time up to few milliseconds and well-resolved signature current-amplitudes were obtained for both sides (3′ or 5′) of the polymer entered the pore, without any modification to ssDNA.
Significantly, M3MspA determines a precise length of a hetero-homopolymer, poly(dA50dC50) by producing a dwell time congruent to the sum of the time spent by their component-homopolymers, separately. On account of their specificity and sensitivity towards translocating
polynucleotides, we suggest that this new mutant of MspA would be a sophisticated bio-nanopore in further enlightening the translocation dynamics caused by diverse conformations of a same biomolecule. On top of that, it would also be helpful in nanopore DNA sequencing.
研究领域:
生物物理学
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纳米技术
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分子生物学
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基因组学
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DOI
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Guoni Huang,Jiezhen Pan,Junfang Zhu,Ye Zhang,Xiaohe Zhang,Shihua Luo
In this study, we introduce an ultrasensitive electrochemical RNA biosensor based on hyperbranched primer exchange reaction (HPER) cascade amplification and Au@Pt@UiO-66-NH 2 nanozymes. This strategy employs catalytic hairpin assembly (CHA) for precise target RNA recognition, which trigger the immobilization of HPER products onto the electrode surface, thereby providing binding sites for nanozymes. Then, the sDNA@Au@Pt@UiO-66-NH 2 signal probes (sDAPU probes) attach to the HPER scaffolds through base-pairing interactions, facilitating signal amplification. The nanozymes catalyze the decomposition of hydrogen peroxide into H 2 O and O 2 , producing a significantly amplified electrochemical signal. By combining CHA-HPER cascade amplification with the catalytic activity of sDAPU probes, the established biosensor achieves remarkable sensitivity, with a detection limit as low as 14.68 aM, and high specificity that enables the differentiation of non-target pathogen RNA. Furthermore, the biosensor also demonstrates excellent recovery rates in serum samples. Therefore, this electrochemical strategy shows great potential as a diagnostic tool for ultrasensitive Mycobacterium tuberculosis detection.
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Lushan Liang,Meng Chen,Yanli Tong,Weiguo Tan,Zuanguang Chen
Herein, a universal fluorescent biosensor was developed for detecting Mycobacterium Tuberculosis (MTB) specific insertion sequence IS6110 gene fragment based on Förster resonance energy transfer (FRET) strategy. CdTe quantum dots (QDs), with excellent luminous performance, were used to label single-stranded DNA (ssDNA) as fluorescence donor (QDs-DNA), in which the ssDNA was complementary to the IS6110 gene fragment. A new type of two-dimensional metal-organic framework (Cu-TCPP) was served as an acceptor. The Cu-TCPP exhibited a higher affinity towards ssDNA than double-stranded DNA (dsDNA). In the absence of targets, the fluorescence of QDs-DNA was quenched – due to the π-π stacking interactions between Cu-TCPP and ssDNA. Otherwise, QDs-DNA hybridized with the target to form a double helix and the fluorescence maintained in a target-concentration dependent manner. Excess QDs-DNA would be quenched and produced negligible background signal. The fluorescent sensor possessed a linear range from 0.05 nM to 1.0 nM with a low detection limit of 35 pM. Furthermore, we successfully applied this biosensing system to detect clinical sputum samples. This method displayed high sensitivity, specificity and great potentials in the early diagnosis of Tuberculosis.
研究领域:
生物技术
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分子生物学
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医学诊断
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DOI
PubMed
高影响因子
BIOMATERIALS
·
2019
·
IF 10.273
Yuhan Chen,Xinzhu Liu,Shuliang Guo,Jun Cao,Jing Zhou,Jianli Zuo,Lijuan Bai
The present work described a novel sandwich-type electrochemical aptasensor for rapid and sensitive determination of Mycobacterium tuberculosis MPT64 antigen. Herein, a novel carbon nanocomposite composed of fullerene nanoparticles , nitrogen-doped carbon nanotubes and graphene oxide (C 60 NPs-N-CNTs/GO) was facilely synthesized for the first time, which not only possessed a large specific surface area and excellent conductivity , but also exhibited outstanding inherent electroactive property, and therefore served as nanocarrier and redox nanoprobe simultaneously. Gold nanoparticles (AuNPs) was then uniformly anchored onto the surface of such nanocomposite via Au–N bonds to bind with MPT64 antigen aptamer Ⅱ (MAA Ⅱ), forming the tracer label to realize generation and amplification of electrochemical signal. Additionally, conductive polyethyleneimine (PEI)-functionalized Fe-based metal-organic framework (P-MOF) was used as a sensing platform to absorb bimetallic core-shell Au–Pt nanoparticles ( [email protected] ), which could accelerate electron transfer and increase the immobilization of MPT64 antigen aptamer Ⅰ (MAA Ⅰ). After the typical sandwich-type protein-aptamer recognition, the inherent electroactivity of the tracer label was provoked by tetraoctylammonium bromide (TOAB), leading to a well-defined current response. Under the optimum condition, the proposed aptasensor showed a wide linear range for MPT64 detection from 1 fg/mL to 1 ng/mL with a limit of detection (LOD) as low as 0.33 fg/mL. More importantly, it was successfully used for MPT64 antigen detection in human serum, exhibiting a promising prospect for TB diagnosis in clinical practice.
研究领域:
分析化学
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纳米技术
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生物医学工程
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电化学
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生物传感器
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医疗诊断
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产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 9
·1-9
·
IF 5.705
Gou Dan,Xie Guoming,Li Yuxia,Zhang Xin,Chen Hui
The authors describe an electrochemical immunoassay for ultrasensitive determination of the Mycobacterium tuberculosis (MTb) secretory protein MPT64 which is an antigen for early diagnosis of infection with MTb . Protein G was used to immobilize antibodies against MPT64 on a gold electrode. Graphene oxide with its large surface area was used as a carrier to anchor magnetite (Fe 3 O 4 ) and platinum (Pt) nanoparticles. The nanocomposite of type GO@Fe 3 O 4 @Pt was used as a signal reporter with excellent catalytic activity and recyclability. The nanocomposite exhibits peroxidase-like activity for hydrogen peroxide, best at −0.25 V (vs. Ag/AgCl). It works over a wide range of pH values (2–10) and temperatures (25–65 °C). Further signal amplification strategy was accomplished by rolling circle amplification. This voltammetric assay has a linear response to the logarithm of MPT64 concentration in the range from 5.0 fg·mL −1 to 1.0 ng·mL −1 and a detection limit of 0.34 fg·mL −1 (at a signal to noise ratio of 3, for n = 10). The assay can be completed within 4 h. It was successfully applied to the determination of MPT64 in spiked serum samples. Conceivably, the assay has a large potential in providing laboratory evidence for rapid diagnosis of MTb infection.
An electrochemical biosensor was developed for rapid detection of Mycobacterium tuberculosis secretory protein MPT64. The detection signal was synergistically amplified by GO@Fe 3 O 4 @Pt and rolling circle amplification. Phi29: phi29 DNA polymerase; BSA: bovine serum albumin; GO: graphene oxide.
研究领域:
医学诊断
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生物传感
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纳米技术
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DOI
PubMed
高影响因子
INTERNATIONAL IMMUNOPHARMACOLOGY
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2017
·
IF 2.956
Zhaoxiao Yu,Chenhui Zhang,Mingliang Zhou,Qiming Li,Hui Li,Wei Duan,Xue Li,Yonghong Feng,Jianping Xie
Tuberculosis (TB), caused by Mycobacterium tuberculosis , remains a formidable threat to global public health . The successful intracellular persistence of M . tuberculosis significantly contributes to the intractability of tuberculosis. Proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) are mycobacterial exclusive protein families that widely reported to be involved in the bacterial virulence , physiology and interaction with host. Rv2770c (PPE44), a predicted virulence factor , was up-regulated upon the infected guinea pig lungs. To investigate the role of Rv2770c, we heterologously expressed the PPE44 in the nonpathogenic fast-growing M . smegmatis strain. Subcellular location analysis demonstrated that Rv2770c is a cell wall associated protein, suggestive of a potential candidate involved in host-pathogen interaction. The Rv2770c can enhance M . smegmatis survival within macrophages and under stresses such as H 2 O 2 , SDS, diamide exposure, and low pH condition. M . smegmatis expressing Rv2770c is more virulent as testified by the increased death of macrophages and the increased expression of interlukin-6 (IL-6) and interlukin-12p40 (IL-12p40). Moreover, Rv2770c altered the secretion of IL-6 and IL-12p40 of macrophages via NF-κB, ERK1/2 and p38 MAPK axis. Taken together, this study implicated that Rv2770c was a virulent factor actively engaged in the interaction with host macrophage.
研究领域:
微生物学
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免疫学
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分子生物学
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DOI
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 12
·1-7
·
IF 5.705
Li Ningning,Huang Xing,Sun Duanping,Yu Weiye,Tan Weiguo,Luo Zhaofan,Chen Zuanguang
An ultrasensitive aptasensor is described for the voltammetric determination of the Mycobacterium tuberculosis antigen MPT64 in human serum. Firstly, an amino-modified Zr(IV) based metal-organic framework (MOF; type UiO-66-NH 2 ; made up from Zr 6 O 32 units and 2-amino-terephthalate linkers) with a high specific surface was synthesized and used as the carrier of the gold nanoparticles and the aptamers. Then the signalling nanoprobe was fabricated after the horseradish peroxidase was cast on the nanomaterials. The two aptamers with synergistic effect on binding MPT64 were anchored on the gold electrode. Differential pulse voltammetry indicated that the peak current is highest if the ratio of the two aptamers is 1:1. The assay has a wide linear response range (0.02 to 1000 pg·mL −1 of MPT64) and a 10 fg·mL −1 detection limit at a working potential of around −96 mV (vs Ag/AgCl). The results show this biosensor to be a viable tool for detection of tuberculosis at an early stage.
Schematic presentation of the construction of the nanoprobe and biosensor. Firstly, the surface of UiO-66-NH 2 was anchored to gold nanoparticles (AuNPs). A dual-aptamer and HRP were added to form the signalling nanoprobe (Aptamer/HRP/AuNPs/UiO-66-NH 2 ). Then, the aptamers I and II were attached on the surface of gold electrode and 6-mercapto-1-hexanol was used to block the uncovered active site of the gold electrode. Finally, after incubation with MPT64, the signalling nanoprobe was dropped on the modified electrode and the DPV measurements was used for the analysis of Mycobacterium tuberculosis antigen MPT64. (PVP: poly(vinyl pyrrolidone); HRP: horseradish peroxidase; MCH: 6-Mercapto-1-hexanol; HQ: hydroquinone; BQ: benzoquinone).
研究领域:
生物传感器
·
电化学
·
纳米技术
·
结核病诊断
·
分析化学
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DOI
PubMed
高影响因子
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