1
|
A lateral flow assay for miRNA-21 based on CRISPR/Cas13a and MnO 2 nanosheets-mediated recognition and signal amplification. Anal Bioanal Chem 2024; 416:3401-3413. [PMID: 38630279 DOI: 10.1007/s00216-024-05290-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/22/2024] [Accepted: 04/04/2024] [Indexed: 05/21/2024]
Abstract
The point-of-care testing (POCT) of miRNA has significant application in medical diagnosis, yet presents challenges due to their characteristics of high homology, low abundance, and short length, which hinders the achievement of quick detection with high specificity and sensitivity. In this study, a lateral flow assay based on the CRISPR/Cas13a system and MnO2 nanozyme was developed for highly sensitive detection of microRNA-21 (miR-21). The CRISPR/Cas13a cleavage system exhibits the ability to recognize the specific oligonucleotide sequence, where two-base mismatches significantly impact the cleavage activity of the Cas13a. Upon binding of the target to crRNA, the cleavage activity of Cas13a is activated, resulting in the unlocking of the sequence and initiating strand displacement, thereby enabling signal amplification to produce a new sequence P1. When applying the reaction solution to the lateral flow test strip, P1 mediates the capture of MnO2 nanosheets (MnO2 NSs) on the T zone, which catalyzes the oxidation of the pre-immobilized colorless substrate 3,3',5,5'-tetramethylbenzidine (TMB) on the T zone and generates the blue-green product (ox-TMB). The change in gray value is directly proportional to the concentration of miR-21, allowing for qualitative detection through visual inspection and quantitative measurement using ImageJ software. This method achieves the detection of miR-21 within a rapid 10-min timeframe, and the limit of detection (LOD) is 0.33 pM. With the advantages of high specificity, simplicity, and sensitivity, the lateral flow test strip and the design strategy hold great potential for the early diagnosis of related diseases.
Collapse
|
2
|
Determination of Acetylcholinesterase Activity Based on Ratiometric Fluorescence Signal Sensing. J Fluoresc 2024:10.1007/s10895-024-03703-y. [PMID: 38613708 DOI: 10.1007/s10895-024-03703-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/05/2024] [Indexed: 04/15/2024]
Abstract
Acetylcholinesterase (AChE) plays an important role in the treatment of human diseases, environmental security and global food supply. In this study, the simple fluorescent indicators and MnO2 nanosheets were developed and integrated to establish a ratiometric fluorescence sensing system for the detection of AChE activity. Two fluorescence signals could be recorded independently at the same excitation wavelength, which extended the detection range and enhanced the visibility of results. Fluorescence of F-PDA was quenched by MnO2 nanosheets on account of inner filtering effect. Meanwhile, the nonfluorescent OPD was catalytically oxidized to 2,3-diaminophenazine by MnO2 nanosheets. The acetylcholine (ATCh) was catalytically hydrolyzed by AChE to enzymatic thiocholine, which decomposed MnO2 to Mn2+, recovered the fluorescence of F-PDA and reduced the emission of ox-OPD. Utilizing the fluorescence intensity ratio F468/F558 as the signal readout, the ratiometric fluorescence method was established to detect AChE activity. Under the excitation wavelength of 410 nm, the ratio F460/F558 against the AChE concentration demonstrated two linear relationships in the range 0.05 -1.0 and 1.0-50 U·L- 1 with a limit of detection (LOD) of 0.073 U·L- 1. The method was applied to the detection of AChE activity and the analysis of the inhibitor Huperzine-A. Due to the advantages of high sensitivity and favorable selectivity, the method possesses an application prospect in the activity deteceion of AChE and the screening of inhibitors.
Collapse
|
3
|
O 2-Generating Fluorescent Carbon Dot-Decorated MnO 2 Nanosheets for "Off/On" MR/Fluorescence Imaging and Enhanced Photodynamic Therapy. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 38037417 DOI: 10.1021/acsami.3c12155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Imaging-guided photodynamic therapy (PDT) has emerged as a promising protocol for cancer theragnostic. However, facile preparation of such a theranostic system for simultaneously achieving tumor location, real-time monitoring, and high-performance reactive oxygen species generation is highly desirable but remains challenging. Herein, we developed a reasonable tumor-targeting strategy based on carbon dots (CDs)-decorated MnO2 nanosheets (HA-MnO2-CDs) with an active magnetic resonance (MR)/fluorescence imaging and enhanced PDT effect. Under light irradiation, the addition of HA-MnO2-CDs increased the production of 1O2 by 2.5 times compared with CDs, providing favorable conditions for the PDT treatment effect on breast cancer. Moreover, HA-MnO2-CDs exhibited excellent performance in producing O2 in the presence of endogenous H2O2, which alleviated hypoxia in tumors and improved the therapeutic effect of PDT. In the presence of glutathione (GSH), the degraded MnO2 nanosheets released CDs and Mn2+ from HA-MnO2-CDs, restoring their fluorescence imaging function and increasing T1 relaxivity (r1) by 23 times. In vivo fluorescence and MR imaging suggested the excellent tumor-targeting property of HA-MnO2-CDs. By combining the complementary properties of nanoprobes and tumor microenvironments, the in vivo PDT therapeutic effect was significantly improved under the action of HA-MnO2-CDs. Overall, our reasonably designed HA-MnO2-CDs may inspire the future development of the next generation of high-performance tumor-responsive diagnostic and therapeutic agents to further enhance the targeted therapy effect of tumors.
Collapse
|
4
|
Atomically Coupled 2D MnO 2/MXene Superlattices for Ultrastable and Fast Aqueous Zinc-Ion Batteries. ACS NANO 2023; 17:21761-21770. [PMID: 37891704 DOI: 10.1021/acsnano.3c07627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/29/2023]
Abstract
The delta manganese dioxide (δ-MnO2) has sparked a great deal of scientific research for application as the cathode in aqueous zinc-ion batteries (AZIBs) owing to its characteristic layered structure. However, further development and commercial application of the δ-MnO2 cathode are hindered by the low rate performance and poor cycling stability, which are derived from its inherently poor electrical conductivity and structural instability during the charge/discharge process. Herein, we report the fabrication of the 2D MnO2/MXene superlattice by the solution-phase assembly of unilamellar MnO2 and Ti3C2Tx MXene nanosheets, where the unilamellar MnO2 nanosheet is separated and stabilized between unilamellar MXene nanosheets. The MXene nanosheets can not only serve as structural stabilizers to isolate the MnO2 nanosheets and prevent them from aggregating but also act as conductive contributors to strengthen the electrical conductivity, thus maintaining the overall structural stability and realizing the rapid electron transport. Additionally, the regular stacking with a repeating periodicity of the 2D MnO2/MXene can lead to highly exposed active sites, promoting ion diffusion. As a consequence, the large specific capacity of 315.1 mAh g-1 at 0.2 A g-1, prominent rate performance of 149.8 mAh g-1 at 5 A g-1, and excellent long-term cycling stability after 5000 cycles with 88.1% capacity retention are obtained for the MnO2/MXene cathode in AZIBs. Meanwhile, the superior H+/Zn2+ diffusion kinetics and desirable pseudocapacitive behaviors are elucidated by electrochemical measurements and density functional theory computations. This study provides an advanced perspective for the innovation of manganese oxide-based cathode materials in AZIBs.
Collapse
|
5
|
A dual-channel sensor array for discrimination of biothiols based on manganese dioxide nanosheets. Mikrochim Acta 2023; 190:294. [PMID: 37458860 DOI: 10.1007/s00604-023-05883-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 06/26/2023] [Indexed: 07/20/2023]
Abstract
A dual-signal sensor array for highly sensitive identification of biothiols is reported based on different optical responses of MnO2/curcumin (CUR) system to different biothiols. The addition of MnO2 nanosheets (MnO2 NSs) quenches the fluorescence of CUR, and the color of the mixture changes from yellow to brown. In the presence of reductive biothiols, MnO2 NSs are etched and lose their fluorescence quenching ability, resulting in an increase in the fluorescence intensity of CUR at 540 nm and a decrease in the absorbance at 430 nm. The sensor array generates specific response modes based on the varying reduction abilities of different biothiols, which can be distinguished by linear discriminant analysis (LDA). The sensor array successfully distinguished five biothiols (glutathione (GSH), dithiothreitol (DTT), cysteine (Cys), mercaptoethanol (ME), and homocysteine (Hcy)) across a wide concentration range (1 μM-100 μM) and biothiol mixtures with varing molar ratios.
Collapse
|
6
|
MnO 2@Au nanostructures supported colorimetric biosensing with duplex-specific nuclease-assisted DNA structural transition. Mater Today Bio 2023; 19:100571. [PMID: 36816603 PMCID: PMC9932214 DOI: 10.1016/j.mtbio.2023.100571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 01/29/2023] [Accepted: 01/31/2023] [Indexed: 02/04/2023] Open
Abstract
Manganese dioxide (MnO2) nanosheets are regarded as a new class of two-dimensional nanomaterials with several attractive properties with enormous progress in biomedical fields. Gold nanoparticles (AuNPs) are also important biocompatible nanomaterials with unusual optical properties. Hetero-nanostructure of MnO2 and AuNPs with the medium of DNA is an interesting topic. In this work, the protection of the hetero-nanostructure from salt-induced aggregation is systematically investigated including the effects of sequence length, reagents concentrations, incubation time and temperature. The MnO2@Au nanostructures are thus applied for the analysis of miRNA. Duplex-specific nuclease (DSN) catalyzed digestion, hybridization chain reaction (HCR) and catalytic hairpin assembly (CHA) are utilized for signal amplification. By finally analyzing the optical responses of the nanocomponents, highly sensitive analysis of target miRNA can be achieved. Excellent analytical performances are attributed to the unique features of MnO2@Au nanostructures and signal amplification designs. They are promising basis for the construction of novel biosensors for clinical applications.
Collapse
|
7
|
Intracellular miRNA Imaging Based on a Self-Powered and Self-Feedback Entropy-Driven Catalyst-DNAzyme Circuit. ACS APPLIED MATERIALS & INTERFACES 2022; 14:39866-39872. [PMID: 36018586 DOI: 10.1021/acsami.2c11923] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
DNAzyme-based signal amplification circuits promote the advances in low-abundant miRNA imaging in living cells. However, due to the insufficient cofactor in living cells and unsustainable target utilization, self-powered and self-feedback DNAzyme amplification circuits have rarely been achieved. Here, a MnO2 nanosheet-mediated self-powered and self-feedback entropy-driven catalyst (EDC)-DNAzyme nanoprobe (MnPFEDz) was demonstrated for sensitive imaging of intracellular microRNA (miRNA). In this strategy, MnPFEDz was formed by adsorbing EDC modules and substrate probes on MnO2 nanosheets. The MnO2 nanosheets acted not only as glutathione (GSH)-responsive nanocarriers for efficient delivery of DNA probes but also as a DNAzyme cofactor supplier to power the DNAzyme biocatalysis and promote signal transduction in a feedback way. When entering the cells, GSH could decompose MnO2 nanosheets to generate numerous Mn2+ ion cofactors, leading to the release of DNA probes. Subsequently, the target miRNA initiated EDC cycles to generate amplified fluorescence signals and exposed the complete DNAzyme. Meanwhile, each of the exposed DNAzyme then cleaved the substrate probes with the help of Mn2+ ion cofactors and released a new trigger analogue for the next round of EDC cycles, initiating additional fluorescence signals in a feedback way. As a multiple signal amplification strategy, the MnPFEDz nanoprobe facilitated the effective detection of intracellular molecules with enhanced sensitivity and provided a versatile strategy for the construction of self-powered and self-feedback DNA circuits in living cells.
Collapse
|
8
|
Injectable Antibacterial Gelatin-Based Hydrogel Incorporated with Two-Dimensional Nanosheets for Multimodal Healing of Bacteria-Infected Wounds. ACS APPLIED BIO MATERIALS 2022; 5:4435-4453. [PMID: 36066957 DOI: 10.1021/acsabm.2c00567] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The design and development of multifunctional injectable hydrogels with high photothermal antibacterial activity and shape adaptability to accelerate bacteria-infected wound healing is of critical importance in clinical applications. In this study, a hybrid hydrogel composed of gelatin, iron, and MnO2 nanosheets was prepared by multiple interactions, including coordinative and hydrogen bonding as well as electrostatic attraction. The introduced MnO2 and Fe components made the hydrogels photothermally and chemodynamically active, thereby endowing them with potent antibacterial capabilities against both Gram-negative and Gram-positive bacteria. Because of the Fenton activity of the hydrogels, they could produce abandoned oxygen, which is highly crucial in the healing process of wounds. They also showed good cytocompatibility and hemocompatibility as well as high hemostatic properties. Moreover, the injectable hydrogels could fill irregular wounds and significantly accelerate bacteria-infected wound healing through decreasing the inflammatory response and increasing blood vessels. These features indicated the promising potential of the multifunctional hydrogel for healing infected full-thickness wounds.
Collapse
|
9
|
Graphitic-phase C 3N 4 nanosheets combined with MnO 2 nanosheets for sensitive fluorescence quenching detection of organophosphorus pesticides. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2022; 57:441-449. [PMID: 35414329 DOI: 10.1080/03601234.2022.2063608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this study, we have developed a sensitive approach to measure organophosphorus pesticides (OPs) using graphitic-phase C3N4 nanosheets (g-C3N4) combined with a nanomaterial-based quencher, MnO2 nanosheets (MnO2 NS). Since MnO2 NS can quench the fluorescence of g-C3N4 via the inner-filter effect (IFE), enzymatic hydrolysate (thiocholine, TCh) can efficiently trigger the decomposition of MnO2 nanosheets in the presence of acetylcholinesterase (AChE) and acetylthiocholine (ATCh), resulting in the fluorescence recovery of g-C3N4. OPs, as inhibitors to AChE activity, can prevent the generation of TCh and decomposition of MnO2 nanosheets while exhibiting fluorescence quenching. Therefore, the AChE-ATCh-MnO2-g-C3N4 system can be utilized to quantitatively detect OPs based on g-C3N4 fluorescence. Under optimal conditions, the linear ranges for the determination of parathion-methyl (PM) and 2,2-dichlorovinyl dimethyl phosphate (DDVP) were found to be 0.1-2.1 ng/mL and 0.5-16 ng/mL, respectively, with limits of detection of 0.069 ng/mL and 0.20 ng/mL, respectively. The advantages of this assay are user-friendliness, ease of use, and cost effectiveness compared to other more sophisticated analytical instruments.
Collapse
|
10
|
A dual-quenched ECL immunosensor for ultrasensitive detection of retinol binding protein 4 based on luminol@AuPt/ZIF-67 and MnO 2@CNTs. J Nanobiotechnology 2021; 19:272. [PMID: 34496877 PMCID: PMC8425071 DOI: 10.1186/s12951-021-01020-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/30/2021] [Indexed: 11/14/2022] Open
Abstract
Background Retinol binding protein 4 (RBP4) has been regarded as an important serological biomarker for type 2 diabetes mellitus (T2DM). Hence, the construction of a highly sensitive detection method for RBP4 is the key to early prevention and multidisciplinary intervention of T2DM. In this work, a dual-quenched electrochemiluminescence (ECL) immunosensor has been fabricated for ultrasensitive detection of RBP4 by combining zeolitic imidazolate framework-67/AuPt-supported luminol (luminol@AuPt/ZIF-67) with MnO2 nanosheets-grown on carbon nanotubes (MnO2@CNTs). Results AuPt/ZIF-67 hybrids with high-efficiency peroxidase-like activity could provide multipoint binding sites for luminol and antibodies and significantly boost the amplified initial signal of the ECL immunosensor. Upon glutathione/H2O2 coreactants system, MnO2@CNTs composites could quench the initial signal by inhibiting mimic peroxidase activity of luminol@AuPt/ZIF-67. Moreover, the absorption spectrum of the MnO2@CNTs composites completely overlaps with the emission spectrum of luminol, which can further reduce initial signal by ECL resonance energy transfer (ECL-RET). Conclusions Benefiting from the above-mentioned properties, the designed immunoassay sensitivity exhibited excellent sensitivity and relative stability for RBP4 detection range from 0.0001 to 100 ng mL−1 with a low detection limit of 43 fg mL−1. Therefore, our ECL immunosensor provides an alternative assaying strategy for early diagnosis of T2DM. Graphic abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12951-021-01020-1.
Collapse
|
11
|
Ratiometric sensing of butyrylcholinesterase activity based on the MnO 2 nanosheet-modulated fluorescence of sulfur quantum dots and o-phenylenediamine. Mikrochim Acta 2021; 188:294. [PMID: 34363549 DOI: 10.1007/s00604-021-04949-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 07/19/2021] [Indexed: 12/14/2022]
Abstract
Butyrylcholinesterase (BChE) can modulate the expression level of cholinesterase, which emerges as an important clinical diagnose index. However, the currently reported assays for BChE are suffering from the problem of interferences. A ratiometric fluorescence assay was developed based on the MnO2 nanosheet (NS)-modulated fluorescence of sulfur quantum dots (S-dots) and o-phenylenediamine (OPD). MnO2 NS can not only quench the fluorescence of blue emissive S-dots, but also enhance the yellow emissive OPD by catalyzing its oxidation reactions. Upon introducing BChE and substrate into the system, their hydrolysate can reduce MnO2 into Mn2+, leading to the fluorescence recovery of S-dots and failure of OPD oxidation. BChE activity can be quantitatively detected by recording the change of fluorescence signals in the blue and yellow regions. A linear relationship is observed between the ratio of F435/F560 and the concentration of BChE in the range 30 to 500 U/L, and a limit of detection of 17.8 U/L has been calculated. The ratiometric fluorescence assay shows an excellent selectivity to acetylcholinesterase and tolerance to various other species. The method developed provides good detection performances in human serum medium and for screening of inhibitors.
Collapse
|
12
|
Universal Nanoplatform for Formaldehyde Detection Based on the Oxidase-Mimicking Activity of MnO 2 Nanosheets and the In Situ Catalysis-Produced Fluorescence Species. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:7303-7312. [PMID: 34160203 DOI: 10.1021/acs.jafc.1c01174] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Formaldehyde (HCHO) pollution is a scientific problem of general concern and has aroused wide attention. In this work, a fluorometric method for sensitive detection of formaldehyde was developed based on the oxidase-mimicking activity of MnO2 nanosheets in the presence of o-phenylenediamine (OPD). The MnO2 nanosheets were prepared by the bottom-up approach using manganese salt as the precursor, followed by the exfoliation with bovine serum albumin. The as-prepared MnO2 nanosheets displayed excellent oxidase-mimicking activity, and can be used as the nanoplatform for sensing in fluorometric analysis. OPD was used as a typical substrate because MnO2 nanosheets can catalyze the oxidation of OPD to generate yellow 2,3-diaminophenazine (DAP), which can emit bright yellow fluorescence at the wavelength of 560 nm. While in the presence of formaldehyde, the fluorescence was greatly quenched because formaldehyde can react with OPD to form Schiff bases that decreased the oxidation reaction of OPD to DAP. The main mechanism and the selectivity of the platform were studied. As a result, formaldehyde can be sensitively detected in a wide linear range of 0.8-100 μM with the detection limit as low as 6.2 × 10-8 M. The platform can be used for the detection of formaldehyde in air, beer, and various food samples with good performance. This work not only expands the application of MnO2 nanosheets in fluorescence sensing, but also provides a sensitive and selective method for the detection of formaldehyde in various samples via a new mechanism.
Collapse
|
13
|
A Safe Flexible Self-Powered Wristband System by Integrating Defective MnO 2-x Nanosheet-Based Zinc-Ion Batteries with Perovskite Solar Cells. ACS NANO 2021; 15:10597-10608. [PMID: 34037383 DOI: 10.1021/acsnano.1c03341] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The booming market of portable and wearable electronics has aroused the requests for advanced flexible self-powered energy systems featuring both excellent performance and high safety. Herein, we report a safe, flexible, self-powered wristband system by integrating high-performance zinc-ion batteries (ZIBs) with perovskite solar cells (PSCs). ZIBs were first fabricated on the basis of a defective MnO2-x nanosheet-grown carbon cloth (MnO2-x@CC), which was obtained via the simple lithium treatment of the MnO2 nanosheets to slightly expand the interlayer spacing and generate rich oxygen vacancies. When used as a ZIB cathode, the MnO2-x@CC with a ultrahigh mass loading (up to 25.5 mg cm-2) exhibits a much enhanced specific capacity (3.63 mAh cm-2 at current density of 3.93 mA cm-2), rate performance, and long cycle stability (no obvious degradation after 5000 cycles) than those of the MnO2@CC. Importantly, the MnO2-x@CC-based quasi-solid-state ZIB not only achieves excellent flexibility and an ultrahigh energy density of 5.11 mWh cm-2 (59.42 mWh cm-3) but also presents a high safety under a wide temperature range and various severe conditions. More importantly, the flexible ZIBs can be integrated with flexible PSCs to construct a safe, self-powered wristband, which is able to harvest light energy and power a commercial smart bracelet. This work sheds light on the development of high-performance ZIB cathodes and thus offers a good strategy to construct wearable self-powered energy systems for wearable electronics.
Collapse
|
14
|
A Cellulose-Derived Nanofibrous MnO 2-TiO 2-Carbon Composite as Anodic Material for Lithium-Ion Batteries. MATERIALS 2021; 14:ma14123411. [PMID: 34202983 PMCID: PMC8234856 DOI: 10.3390/ma14123411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/11/2021] [Accepted: 06/17/2021] [Indexed: 11/29/2022]
Abstract
A bio-inspired nanofibrous MnO2-TiO2-carbon composite was prepared by utilizing natural cellulosic substances (e.g., ordinary quantitative ashless filter paper) as both the carbon source and structural matrix. Mesoporous MnO2 nanosheets were densely immobilized on an ultrathin titania film precoated with cellulose-derived carbon nanofibers, which gave a hierarchical MnO2-TiO2-carbon nanoarchitecture and exhibited excellent electrochemical performances when used as an anodic material for lithium-ion batteries. The MnO2-TiO2-carbon composite with a MnO2 content of 47.28 wt % exhibited a specific discharge capacity of 677 mAh g−1 after 130 repeated charge/discharge cycles at a current rate of 100 mA g−1. The contribution percentage of MnO2 in the composite material is equivalent to 95.1% of the theoretical capacity of MnO2 (1230 mAh g−1). The ultrathin TiO2 precoating layer with a thickness ca. 2 nm acts as a crucial interlayer that facilitates the growth of well-organized MnO2 nanosheets onto the surface of the titania-carbon nanofibers. Due to the interweaved network structures of the carbon nanofibers and the increased content of the immobilized MnO2, the exfoliation and aggregation, as well as the large volume change of the MnO2 nanosheets, are significantly inhibited; thus, the MnO2-TiO2-carbon electrodes displayed outstanding cycling performance and a reversible rate capability during the Li+ insertion/extraction processes.
Collapse
|
15
|
MOF@MnO 2nanocomposites prepared using in situmethod and recyclable cholesterol oxidase-inorganic hybrid nanoflowers for cholesterol determination. NANOTECHNOLOGY 2021; 32:315502. [PMID: 33836512 DOI: 10.1088/1361-6528/abf692] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
In this work, through thein situgrowth of MnO2nanosheets on the surface of terbium metal-organic frameworks (Tb-MOFs), MOF@MnO2nanocomposites are prepared and the fluorescence of Tb-MOFs is quenched significantly by MnO2. Additionally, the hybrid nanoflowers are self-assembled by cholesterol oxidase (ChOx) and copper phosphate (Cu3(PO4)2·3H2O). Then a new strategy for cholesterol determination is developed based on MOF@MnO2nanocomposites and hybrid nanoflowers. Cholesterol is oxidized under the catalysis of hybrid nanoflowers to yield H2O2, which further reduces MnO2nanosheets into Mn2+. Hence, the fluorescence recovery of Tb-MOFs is positively correlated to the concentration of cholesterol in the range of 10 to 360μM. The limit of detection (LOD) of cholesterol is 1.57μM. On the other hand, the hierarchical and confined structure of ChOx-inorganic hybrid nanoflowers greatly improve the stability of the enzyme. The activity of hybrid nanoflowers remains at a high level for one week when stored at room temperature. Moreover, the hybrid nanoflowers can be collected by centrifugation and reused. The activity of hybrid nanoflowers can continue at a high level for five cycles of determination. Therefore, it can be concluded that the hybrid nanoflowers are more stable and more economic than free enzymes, and they show a similar sensitivity and specificity to cholesterol compared with free ChOx. Finally, this strategy has been further validated for the determination of cholesterol in serum samples with satisfactory recoveries.
Collapse
|
16
|
Oxidase-like Nanozyme-Mediated Altering of the Aspect Ratio of Gold Nanorods for Breaking through H 2O 2-Supported Multicolor Colorimetric Assay: Application in the Detection of Acetylcholinesterase Activity and Its Inhibitors. ACS APPLIED BIO MATERIALS 2021; 4:3539-3546. [PMID: 35014439 DOI: 10.1021/acsabm.1c00069] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A convenient, fast, and colorful colorimetric platform with high resolution for acetylcholinesterase (AChE) activity and its inhibitors detection based on the regulation of oxidase-like nanozyme-mediated etching of gold nanorods (AuNRs) has been proposed in this work. MnO2 nanosheets are selected as the nanozyme. Their excellent oxidase-like activity enables the etching process to proceed smoothly without the usage of unstable H2O2. When AChE is present, it catalytically hydrolyzes acetylthiocholine (ATCh) to thiocholine (TCh). With high reducing ability, TCh induces the decomposition of MnO2 nanosheets, causing them to lose their oxidase-like activity. Thus, the etching of AuNRs is hampered. Consequently, with the increasing concentration of AChE, an apparent change in the AuNRs solution color is observed. The proposed platform achieves high-sensitivity detection of AChE (limit of detection = 0.18 mU/mL). Furthermore, the proposed platform also has been demonstrated its applicability for its inhibitors detection. Benefiting from the advantages of convenient and high resolution of visual readout, the proposed platform holds great potential for the detection of AChE and its inhibitors in clinical diagnosis.
Collapse
|
17
|
A MnO 2 nanosheet-assisted ratiometric fluorescence probe based on carbon quantum dots and o-phenylenediamine for determination of 6-mercaptopurine. Mikrochim Acta 2021; 188:156. [PMID: 33825037 DOI: 10.1007/s00604-021-04802-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/20/2021] [Indexed: 12/25/2022]
Abstract
A MnO2 nanosheet-assisted ratiometric fluorescence probe based on carbon quantum dots (CQDs) and o-phenylenediamine (OPD) has been developed for the detection of the anticancer drug 6-mercaptopurine (6-MP). CQDs with strong fluorescence are synthesized via the one-step hydrothermal method. MnO2 nanosheets as an oxidase-mimicking nanomaterial directly oxidize OPD into 2,3-diaminophenazine (DAP) which has a fluorescence emission at 570 nm, whereas the fluorescence of CQDs at 445 nm is then reduced by the DAP through the inner filter effect (IFE) under a single excitation wavelength (370 nm). After adding 6-MP, MnO2 nanosheets can be reduced to Mn2+ and lose their oxidase-like property, blocking the IFE with the fluorescence decrease of DAP and fluorescence increase of CQDs. The novel ratiometric fluorescence probe exhibits considerable sensitivity toward 6-MP and linear response is in the 0.46-100.0 μmol L-1 concentration range with the detection limit of 0.14 μmol L-1. Furthermore, the probe shows good selectivity when exposed to a series of interfering other organic and inorganic compounds, and biomolecules and can be applied to the detection for 6-MP in human serum samples and pharmaceutical tablets. Satisfactory recoveries of 6-MP in human serum samples are in the range 96.1-110.9% with the RSD of 1.4 to 3.2%. The amount of 6-MP is successfully estimated as 49.3 mg in pharmaceutical tablet with the RSD of about 2.2%.
Collapse
|
18
|
A ratiometric fluorescence probe based on graphene quantum dots and o-phenylenediamine for highly sensitive detection of acetylcholinesterase activity. Mikrochim Acta 2020; 187:511. [PMID: 32833082 DOI: 10.1007/s00604-020-04522-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/19/2020] [Indexed: 12/14/2022]
Abstract
By using graphene quantum dots (GQDs) and o-phenylenediamine (OPD), a ratiometric fluorescence probe was designed for the highly sensitive and selective detection of AChE. GQDs with strong fluorescence were synthesized by the one-step hydrothermal method. The optimal emission wavelength of GQDs was 450 nm at the excitation wavelength of 375 nm. MnO2 nanosheets with a wide absorption band of 300-600 nm were prepared at room temperature. Because of the extensive overlap between the absorption spectrum of MnO2 nanosheets and the excitation and emission spectra of GQDs, the fluorescence of GQDs at 450 nm was efficiently quenched by the inner-filter effect. Meanwhile, due to the peroxidase-like activity of MnO2 nanosheets, OPD was catalytically oxidized to 2,3-diaminophenazine (oxOPD), a yellow fluorescent substance with a new emission peak at 572 nm. When AChE was present, the substrate acetylthiocholine (ATCh) was hydrolyzed to thiocholine (TCh) that is capable of decomposing MnO2 nanosheets. Therefore, the quench of GQDs and the oxidation of OPD by MnO2 nanosheets were suppressed, resulting in the fluorescence recovery of GQDs at 450 nm, while the fluorescence decrease of oxOPD at 572 nm. Utilizing the fluorescence intensity ratio F450/F572 as the signal readout, the ratiometric fluorescence method was established to detect AChE activity. The ratio F450/F572 against the AChE concentration demonstrated two linear relationships in the range 0.1-2.0 and 2.0-4.5 mU mL-1 with a detection limit of 0.09 mU mL-1. The method was applied to the detection of positive human serum samples and the analysis of the inhibitor neostigmine. Due to the advantages of high sensitivity, favorable selectivity, and strong anti-interference, the method possesses an application prospect in clinical diagnosis of AChE and the screening of inhibitors. Graphical abstract Schematic presentation of a ratiometric fluorescence method for the detection of acetylcholinesterase (AChE). The fluorescence of graphene quantum dots (GQDs) is quenched and o-phenylenediamine (OPD) is oxidized to generate fluorescent product 2,3-diaminophenazine (oxOPD) by MnO2 nanosheets. When AChE is present, acetylthiocholine iodide (ATCh) is hydrolyzed to thiocholine (TCh) with reducibility for decomposing MnO2 nanosheets. Due to the decomposition of MnO2 nanosheets, the quenching of GQDs and oxidation of OPD are suppressed. The fluorescence of GQDs at 450 nm is enhanced, while the fluorescence of oxOPD at 572 nm is reduced. The fluorescence intensity ratio F450/F572 is used to establish the ratiometric fluorescence method for AChE activity.
Collapse
|
19
|
Manganese dioxide nanosheets: from preparation to biomedical applications. Int J Nanomedicine 2019; 14:4781-4800. [PMID: 31308658 PMCID: PMC6613456 DOI: 10.2147/ijn.s207666] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 05/23/2019] [Indexed: 12/15/2022] Open
Abstract
Advancements in nanotechnology and molecular biology have promoted the development of a diverse range of models to intervene in various disorders (from diagnosis to treatment and even theranostics). Manganese dioxide nanosheets (MnO2 NSs), a typical two-dimensional (2D) transition metal oxide of nanomaterial that possesses unique structure and distinct properties have been employed in multiple disciplines in recent decades, especially in the field of biomedicine, including biocatalysis, fluorescence sensing, magnetic resonance imaging and cargo-loading functionality. A brief overview of the different synthetic methodologies for MnO2 NSs and their state-of-the-art biomedical applications is presented below, as well as the challenges and future perspectives of MnO2 NSs.
Collapse
|
20
|
A dual (colorimetric and fluorometric) detection scheme for glutathione and silver (I) based on the oxidase mimicking activity of MnO 2 nanosheets. Mikrochim Acta 2019; 186:498. [PMID: 31270601 DOI: 10.1007/s00604-019-3613-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/14/2019] [Indexed: 02/01/2023]
Abstract
A fluorimetric and colorimetric method is described for the determination of glutathione (GSH) and silver (I). It is based on the use of MnO2 nanosheets that were prepared by solution mixing and exfoliation. They display oxidase-mimicking activity and can catalyze the oxidation of o-phenylenediamine (OPD) to form yellow 2,3-diaminophenazine (DAP) with an absorption maximum at 410 nm. DAP also has a yellow fluorescence (with a peak at 560 nm). The MnO2 nanosheets can be rapidly reduced to Mn2+ by GSH. This reduces the efficiency of the oxidase mimic MnO2 and causes a decrease in fluorescence and absorbance intensity. However, on addition of Ag+, a complex is formed with GSH. It prevents the destruction of MnO2 nanosheets so that the enzyme mimicking activity is retained. A dual-method for the determination of GSH and Ag(I) was developed. It has excellent sensitivity for GSH with lower detection limits of 62 nM (fluorimetric) and 0.94 μM (colorimetric). The respective data for Ag(I) are 70 nM and 1.15 μM. The assay was successfully applied to the determination of GSH and Ag(I) in spiked serum samples. Graphical abstract Schematic presentation of a method for colorimetric and fluorometric determination of glutathione (GSH) and silver(I). MnO2 nanosheets are reduced to Mn(II) by GSH. This reduces the enzyme-mimicking activity of MnO2 nanosheets and causes a decrease in fluorescence and absorbance. On addition of Ag(I), the enzyme-like activity is increasingly retained. A decrease in fluorescence and absorbance is not observed any longer.
Collapse
|
21
|
Rapid and Highly Effective Noninvasive Disinfection by Hybrid Ag/CS@MnO 2 Nanosheets Using Near-Infrared Light. ACS APPLIED MATERIALS & INTERFACES 2019; 11:15014-15027. [PMID: 30933472 DOI: 10.1021/acsami.8b22136] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A bacterial infection on the surface of medical apparatus and instruments as well as artificial implants is threatening human health greatly. Antibiotics and traditional bacterial-killing agents, even silver nanoparticles, can induce bacterial resistance during long-term interaction with bacteria. Hence, rapid surface sterilization and prevention of bacterial infection in the long term are urgent for biomedical devices, especially for artificial implant materials. Herein, a hybridized chitosan (CS), silver nanoparticles (AgNPs), and MnO2 nanosheets coating was designed on the surface of titanium plates, which can ensure the implants a rapid and highly effective antibacterial efficacy of 99.00% against Staphylococcus aureus ( S. aureus) and 99.25% against Escherichia coli ( E. coli) within 20 min of 808 nm near-infrared light (NIR) irradiation. The exogenous NIR irradiation can trigger the MnO2 nanosheets to produce enough hyperthermia within 10 min, which can combine with a low concentration of prereleased Ag+ from the coating to achieve superior antimicrobial efficacy through synergistic effects. In contrast, either prereleased Ag ions or a photothermal effect alone can achieve much lower antibacterial efficiency under the same concentration, i.e., 24.00% and 30.01% for the former and 30.00% and 42.54% for the later toward S. aureus and E. coli, respectively. The possible cytotoxicity of coatings could be eliminated owing to the low concentration of AgNPs and chitosan encapsulation. Thus, the novel bifunctional coating Ag/CS@MnO2 can exhibit great potential in deep site disinfection of Ti implants through the synergy of prereleased Ag ions and a photothermal effect within a short time.
Collapse
|
22
|
Diatom Microbubbler for Active Biofilm Removal in Confined Spaces. ACS APPLIED MATERIALS & INTERFACES 2018; 10:35685-35692. [PMID: 30107112 PMCID: PMC8216637 DOI: 10.1021/acsami.8b08643] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Bacterial biofilms form on and within many living tissues, medical devices, and engineered materials, threatening human health and sustainability. Removing biofilms remains a grand challenge despite tremendous efforts made so far, particularly when they are formed in confined spaces. One primary cause is the limited transport of antibacterial agents into extracellular polymeric substances (EPS) of the biofilm. In this study, we hypothesized that a microparticle engineered to be self-locomotive with microbubbles would clean a structure fouled by biofilm by fracturing the EPS and subsequently improving transports of the antiseptic reagent. We examined this hypothesis by doping a hollow cylinder-shaped diatom biosilica with manganese oxide (MnO2) nanosheets. In an antiseptic H2O2 solution, the diatoms doped by MnO2 nanosheets, denoted as diatom bubbler, discharged oxygen gas bubbles continuously and became self-motile. Subsequently, the diatoms infiltrated the bacterial biofilm formed on either flat or microgrooved silicon substrates and continued to generate microbubbles. The resulting microbubbles merged and converted surface energy to mechanical energy high enough to fracture the matrix of biofilm. Consequently, H2O2 molecules diffused into the biofilm and killed most bacterial cells. Overall, this study provides a unique and powerful tool that can significantly impact current efforts to clean a wide array of biofouled products and devices.
Collapse
|
23
|
Smartly Designed Hierarchical MnO 2 @Fe 3 O 4 /CNT Hybrid Films as Binder-free Anodes for Superior Lithium Storage. Chem Asian J 2018; 13:3027-3031. [PMID: 30126056 DOI: 10.1002/asia.201800922] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/15/2018] [Indexed: 01/08/2023]
Abstract
Nowadays, the development of advanced anode materials is highly desirable for the increasing demand for high-performance lithium-ion batteries (LIBs). Nanostructured MnO2 has received utmost attention due to high theoretical capacity (1230 mA h g-1 ), abundant resources, environmental benignity, and shortened electron and ion diffusion paths. Unfortunately, poor electronic conductivity and strong aggregation inclination of MnO2 nanostructures result in disappointing electrochemical performances, which restrict their practical application as sole institute. Here, we propose smartly designed MnO2 @Fe3 O4 /CNT hybrid films, in which MnO2 nanosheets, Fe3 O4 nanoparticles and CNTs are hierarchically assembled in a unique stage of nanosheets-nanoparticles-nanotubes. The resulting MnO2 @Fe3 O4 /CNT hybrid films can be directly used as anodes without any polymer binders, and exhibit significant synergistic interactions among three components, achieving excellent reversible capacity and rate performance.
Collapse
|
24
|
Abstract
A novel fluorescence sensing platform for ultrasensitive detection of S1 nuclease activity has been constructed based on MnO2 nanosheets and FAM labeled single-stranded DNA (FAM-ssDNA). In this system, MnO2 nanosheets were found to have different adsorbent ability toward ssDNA and mono- or oligonucleotide fragments. FAM-ssDNA could adsorb on MnO2 nanosheets and resulted in significant fluorescence quenching through fluorescence resonance energy transfer (FRET), while mono- or oligonucleotide fragments could not adsorb on MnO2 nanosheets and still retained strong fluorescence emission. With the addition of S1 nuclease, FAM-ssDNA was cleaved into mono- or oligonucleotide fragments, which were not able to adsorb on MnO2 nanosheets and the fluorescence signal was never quenched. The different fluorescence intensity allowed for examination of S1 nuclease activity. The developed method can detect S1 nuclease activity in the range of 0 - 20 U mL-1 with a detection limit of 0.05 U mL-1. Benefits of the system include less time-consuming processes and more simple design compared to other endonuclease assays. Satisfactory performance for S1 nuclease in complex samples has been successfully demonstrated with the system. The developed assay could potentially provide a new platform in bioimaging and clinical diagnosis.
Collapse
|
25
|
A Simple and Effective Colorimetric Assay for Glucose Based on MnO₂ Nanosheets. SENSORS 2018; 18:s18082525. [PMID: 30072628 PMCID: PMC6111558 DOI: 10.3390/s18082525] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 07/26/2018] [Accepted: 07/28/2018] [Indexed: 12/31/2022]
Abstract
Simple and effective methods for the detection of the level of blood glucose are closely linked to the monitoring of people's health. In the study, MnO₂ nanosheets with absorption range of 300 nm~500 nm and obvious yellow color were easily prepared and applied to detect glucose through their absorbance and color. The proposed method is based on the fact that a specific concentration of glucose can be quantitatively transformed into hydrogen peroxide (H₂O₂) under the catalytic effect of glucose oxidase. Based on the redox reaction of MnO₂ with H₂O₂, yellow MnO₂ can be converted into colorless Mn2+ to monitor the concentration of glucose. Under optimal conditions, a simple and effective visual assay for the sensitive and reliable detection of glucose was developed. The linear range was estimated to the range from 0 μM to 100 μM, with a detection limit of 12.8 μM. Furthermore, the proposed colorimetric assay based on MnO₂ nanosheets can effectively detect blood glucose of clinical serum samples with accuracy and convenience.
Collapse
|
26
|
Fluorometric determination of microRNA-155 in cancer cells based on carbon dots and MnO 2 nanosheets as a donor-acceptor pair. Mikrochim Acta 2018; 185:372. [PMID: 29995191 DOI: 10.1007/s00604-018-2868-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 06/08/2018] [Indexed: 10/28/2022]
Abstract
A fluorometric method is presented for sensitive deternination of microRNA. It is making use of carbon dots (C-dots) loaded with a DNA probe as fluorophore and MnO2 nanosheets as the quenching agent. The blue-green fluorescence of the DNA-loaded C-dots is quenched by the MnO2 nanosheets, but restored on binding target microRNA-155. The maximum excitation wavelength and the maximum emission wavelength of C-dots are at 360 nm and 455 nm, respectively. Fluorescence correlates linearly with the log of the microRNA-155 concentration in two ranges, viz. from 0.15 to 1.65 aM and from 1.65 to 20 aM. The detection limit is as low as 0.1 aM. The assay can discriminate between fully complementary and single-base mismatch microRNA. The assay displayed high specificity when used to detect MCF-7 breast cancer cells which can be detected in concentrations from 1000 to 45,000 cells·mL-1, with a 600 cells·mL-1 detection limit. The method was applied to the analysis of serum samples spiked with microRNA, and satisfactory results were acquired. Graphical abstract Schematic of a fluorometric sensing platform for miRNA-155. The method relies on a FRET process between C-dots and MnO2 nanosheets. This strategy has a practical application for detection of miRNA in cell lines and biological fluids.
Collapse
|
27
|
FRET Effect between Fluorescent Polydopamine Nanoparticles and MnO 2 Nanosheets and Its Application for Sensitive Sensing of Alkaline Phosphatase. ACS APPLIED MATERIALS & INTERFACES 2018; 10:6560-6569. [PMID: 29384352 DOI: 10.1021/acsami.7b18816] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
As an essential and universal hydrolase, alkaline phosphatase (ALP) has been identified as a crucial indicator of various diseases. Herein, we, for the first time, expanded the application of fluorescent polydopamine (F-PDA) nanoparticles to nanoquencher-based biosensing system, as well as discovered the reversible quenching effect of manganese dioxide (MnO2) nanosheets on the fluorescence of F-PDA nanoparticles and intensively confirmed the quenching mechanism of Förster resonance energy transfer by using transmission electron microscopy, UV-vis, Fourier transform infrared spectroscopy, and fluorescence lifetime experiments. By means of the ALP-triggered generation of ascorbic acid (AA) from the substrate ascorbic acid 2-phosphate, the AA-triggered reduction of MnO2 nanosheets to Mn2+, as well as the clear quenching mechanism of F-PDA nanoparticles by MnO2 nanosheets, we have developed a label-free, low-cost, visual, and facile synthetic fluorescent biosensor for convenient assay of ALP activity. The fluorescent bioassay shows a good linear relationship from 1 to 80 mU/mL (R2 = 0.999), with a low detection limit of 0.34 mU/mL, and the excellent applicability in human serum samples demonstrates potential applications in clinical diagnosis and biomedical research.
Collapse
|
28
|
MnO 2-graphene nanosheets wrapped mesoporous carbon/sulfur composite for lithium-sulfur batteries. ROYAL SOCIETY OPEN SCIENCE 2018; 5:171824. [PMID: 29515889 PMCID: PMC5830778 DOI: 10.1098/rsos.171824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/04/2018] [Indexed: 03/14/2024]
Abstract
MnO2-graphene nanosheets wrapped mesoporous carbon/sulfur (MGN@MC/S) composite is successfully synthesized derived from metal-organic frameworks and investigated as cathode for lithium-ion batteries. Used as cathode, MGN@MC/S composite possesses electronic conductivity network for redox electron transfer and strong chemical bonding to lithium polysulfides, which enables low capacity loss to be achieved. MGN@MC/S cathodes exhibit high reversible capacity of 1475 mA h g-1 at 0.1 C and an ultra-low capacity fading of 0.042% per cycle at 1 C over 450 cycles.
Collapse
|
29
|
Detection of glutathione based on MnO 2 nanosheet-gated mesoporous silica nanoparticles and target induced release of glucose measured with a portable glucose meter. Mikrochim Acta 2017; 185:44. [PMID: 29594599 DOI: 10.1007/s00604-017-2603-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/01/2017] [Indexed: 12/31/2022]
Abstract
The authors describe a novel method for the determination of glutathione (GSH). Detection is based on target induced release of glucose from MnO2 nanosheet-gated aminated mesoporous silica nanoparticles (MSNs). In detail, glucose is loaded into the pores of MSNs. Negatively charged MnO2 nanosheets are assembled on the MSNs through electrostatic interactions. The nanosheets are reduced by GSH, and this results in the release of glucose which is quantified by using a commercial electrochemical glucose meter. GSH can be quantified by this method in the 100 nM to 10 μM concentration range, with a 34 nM limit of detection. Graphical abstract Glucose is loaded into the pores of mesoporous silica nanoparticles (MSNs). MnO2 nanosheets are assembled on MSNs through electrostatic interactions. Glutathione (GSH) can reduce the nanosheets, and this results in the release of glucose which is quantified by using a commercial glucose meter.
Collapse
|
30
|
Active Antioxidizing Particles for On-Demand Pressure-Driven Molecular Release. ACS APPLIED MATERIALS & INTERFACES 2017; 9:35642-35650. [PMID: 28961399 PMCID: PMC7042956 DOI: 10.1021/acsami.7b12297] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Overproduced reactive oxygen species (ROS) are closely related to various health problems including inflammation, infection, and cancer. Abnormally high ROS levels can cause serious oxidative damage to biomolecules, cells, and tissues. A series of nano- or microsized particles has been developed to reduce the oxidative stress level by delivering antioxidant drugs. However, most systems are often plagued by slow molecular discharge, driven by diffusion. Herein, this study demonstrates the polymeric particles whose internal pressure can increase upon exposure to H2O2, one of the ROS, and in turn, discharge antioxidants actively. The on-demand pressurized particles are assembled by simultaneously encapsulating water-dispersible manganese oxide (MnO2) nanosheets and green tea derived epigallocatechin gallate (EGCG) molecules into a poly(lactic-co-glycolic acid) (PLGA) spherical shell. In the presence of H2O2, the MnO2 nanosheets in the PLGA particle generate oxygen gas by decomposing H2O2 and increase the internal pressure. The pressurized PLGA particles release antioxidative EGCG actively and, in turn, protect vascular and brain tissues from oxidative damage more effectively than the particles without MnO2 nanosheets. This H2O2 responsive, self-pressurizing particle system would be useful to deliver a wide array of molecular cargos in response to the oxidation level.
Collapse
|
31
|
A Smart Photosensitizer-Manganese Dioxide Nanosystem for Enhanced Photodynamic Therapy by Reducing Glutathione Levels in Cancer Cells. Angew Chem Int Ed Engl 2016; 55:5477-82. [PMID: 27010667 DOI: 10.1002/anie.201510748] [Citation(s) in RCA: 392] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 12/28/2015] [Indexed: 12/25/2022]
Abstract
Photodynamic therapy (PDT) has been applied in cancer treatment by utilizing reactive oxygen species to kill cancer cells. However, a high concentration of glutathione (GSH) is present in cancer cells and can consume reactive oxygen species. To address this problem, we report the development of a photosensitizer-MnO2 nanosystem for highly efficient PDT. In our design, MnO2 nanosheets adsorb photosensitizer chlorin e6 (Ce6), protect it from self-destruction upon light irradiation, and efficiently deliver it into cells. The nanosystem also inhibits extracellular singlet oxygen generation by Ce6, leading to fewer side effects. Once endocytosed, the MnO2 nanosheets are reduced by intracellular GSH. As a result, the nanosystem is disintegrated, simultaneously releasing Ce6 and decreasing the level of GSH for highly efficient PDT. Moreover, fluorescence recovery, accompanied by the dissolution of MnO2 nanosheets, can provide a fluorescence signal for monitoring the efficacy of delivery.
Collapse
|
32
|
Intelligent MnO2 Nanosheets Anchored with Upconversion Nanoprobes for Concurrent pH-/H2O2-Responsive UCL Imaging and Oxygen-Elevated Synergetic Therapy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:4155-61. [PMID: 26058562 DOI: 10.1002/adma.201405141] [Citation(s) in RCA: 481] [Impact Index Per Article: 53.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 05/08/2015] [Indexed: 05/28/2023]
|
33
|
Enhanced tolerance to stretch-induced performance degradation of stretchable MnO2-based supercapacitors. ACS APPLIED MATERIALS & INTERFACES 2015; 7:2569-2574. [PMID: 25569836 DOI: 10.1021/am507588p] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The performance of many stretchable electronics, such as energy storage devices and strain sensors, is highly limited by the structural breakdown arising from the stretch imposed. In this article, we focus on a detailed study on materials matching between functional materials and their conductive substrate, as well as enhancement of the tolerance to stretch-induced performance degradation of stretchable supercapacitors, which are essential for the design of a stretchable device. It is revealed that, being widely utilized as the electrode material of the stretchable supercapacitor, metal oxides such as MnO2 nanosheets have serious strain-induced performance degradation due to their rigid structure. In comparison, with conducting polymers like a polypyrrole (PPy) film as the electrochemically active material, the performance of stretchable supercapacitors can be well preserved under strain. Therefore, a smart design is to combine PPy with MnO2 nanosheets to achieve enhanced tolerance to strain-induced performance degradation of MnO2-based supercapacitors, which is realized by fabricating an electrode of PPy-penetrated MnO2 nanosheets. The composite electrodes exhibit a remarkable enhanced tolerance to strain-induced performance degradation with well-preserved performance over 93% under strain. The detailed morphology and electrochemical impedance variations are investigated for the mechanism analyses. Our work presents a systematic investigation on the selection and matching of electrode materials for stretchable supercapacitors to achieve high performance and great tolerance to strain, which may guide the selection of functional materials and their substrate materials for the next-generation of stretchable electronics.
Collapse
|
34
|
Break-up of two-dimensional MnO2 nanosheets promotes ultrasensitive pH-triggered theranostics of cancer. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:7019-26. [PMID: 25156250 DOI: 10.1002/adma.201402572] [Citation(s) in RCA: 303] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 07/03/2014] [Indexed: 05/20/2023]
Abstract
Chemically exfoliated two-dimensional MnO2 nanosheets are successfully modified with amino-polyethylene glycol as a theranostic platform for ultrasensitive stimuli-responsive theranostics of cancer. The highly dispersed MnO2 nanosheets exhibit a unique break-up in the mildly acidic microenvironment of tumor tissues, which could substantially enhance their in vitro and in vivo performances in T1 -weighted magnetic resonance imaging. Such a pH-triggered breaking-up behavior could further promote the fast release of loaded anticancer drugs for concurrent pH-responsive drug release and circumvent the multidrug resistance of cancer cells.
Collapse
|