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1.
Adv Sci (Weinh) ; : e2403249, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39013078

ABSTRACT

Exploring the molecular packing and interaction between chiral molecules, no matter single enantiomer or racemates, is important for recognition and resolution of chiral drugs. However, sensitive and non-destructive analysis methods are lacking. Herein, an intermolecular-charge transfer (ICT) based spectroscopy is reported to reveal the differences in interaction between the achiral acceptor 1,2,4,5-tetracyanobenzene (TCNB) and the chiral donors, including S, R, and racemic naproxen (S/R/rac-NAP). In this process, S-NAP+TCNB and R-NAP+TCNB display a narrower band gap attributed to the newly formed ICT state. In contrast, the mixed rac-NAP and TCNB exhibit almost no significant change due to the strong affinity between the stereoisomers according to the Wallach's rule. Thus, S/R-NAP can be easily distinguished from rac-NAP based on significantly different optical behavior. The single crystal analysis, infrared spectroscopy, fluorescence spectroscopy, and theoretical calculation of naproxen confirm the importance of carboxyl for this differentiation in molecular packing and interaction. In addition, the esterification derivatization of naproxen achieves the manipulation of the intermolecular interaction model of racemates from the absolute Wallach's rule to a coexisting form of Wallach's rule and ICT. Further, visualized chiral purification of naproxen by the simple cocrystallization method is achieved through the collaboration of ICT and Wallach's rule.

2.
Spectrochim Acta A Mol Biomol Spectrosc ; 322: 124788, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38986256

ABSTRACT

MicroRNAs (miRNAs) play a key role in physiological processes, and their dysregulation is closely related to various human diseases. Simultaneous detection of multiple miRNAs is pivotal to cancer diagnosis at an early stage. However, most multicomponent analyses generally involve multiple excitation wavelengths, which are complicated and often challenging to simultaneously acquire multiple detection signals. In this study, a convenient and sensitive sensor was developed to simultaneously detection of multiple miRNAs under a single excitation wavelength through the fluorescence resonance energy transfer between the carbon dots (CDs)/quantum dots (QDs) and graphene oxide (GO). A hybridization chain reaction (HCR) was triggered by miRNA-141 and miRNA-21, resulting in the high sensitivity with a limit of detection (LOD) of 50 pM (3σ/k) for miRNA-141 and 60 pM (3σ/k) for miRNA-21. This simultaneous assay also showed excellent specificity discrimination against the mismatch. Furthermore, our proposed method successfully detected miRNA-21 and miRNA-141 in human serum samples at a same time, indicating its diagnostic potential in a clinical setting.

3.
Anal Chem ; 96(28): 11498-11507, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38946253

ABSTRACT

The determination of pH values is crucial in various fields, such as analytical chemistry, medical diagnostics, and biochemical research. pH test strips, renowned for their convenience and cost-effectiveness, are commonly utilized for pH qualitative estimation. Recently, quantitative methods for determining pH values using pH test strips have been developed. However, these methods can be prone to errors due to environmental factors, such as lighting conditions, which affect the imaging quality of the pH test strips. To address these challenges, we developed an innovative approach that combines machine learning techniques with pH test strips for the quantitative determination of pH values. Our method involves extracting artificial features from the pH test strip images and combining them across multiple dimensions for comprehensive analysis. To ensure optimal feature selection, we developed a feature selection strategy based on SHAP importance. This strategy helps in identifying the most relevant features that contribute to accurate pH prediction. Furthermore, we integrated multiple machine learning algorithms, employing a robust stacking fusion strategy to establish a highly reliable pH value prediction model. Our proposed method automates the determination of pH values through pH test strips, effectively overcoming the limitations associated with environmental lighting interference. Experimental results demonstrate that this method is convenient, effective, and highly reliable for the determination of pH values.

4.
Anal Chem ; 96(10): 4282-4289, 2024 Mar 12.
Article in English | MEDLINE | ID: mdl-38469640

ABSTRACT

Chirality is a widespread phenomenon in nature and in living organisms and plays an important role in living systems. The sensitive discrimination of chiral molecular enantiomers remains a challenge in the fields of chemistry and biology. Establishing a simple, fast, and efficient strategy to discriminate the spatial configuration of chiral molecular enantiomers is of great significance. Chiral perovskite nanocrystals (PNCs) have attracted much attention because of their excellent optical activity. However, it is a challenge to prepare perovskites with both chiral and fluorescence properties for chiral sensing. In this work, we synthesized two chiral fluorescent perovskite nanocrystal assembly (PNA) enantiomers by using l- or d-phenylalanine (Phe) as chiral ligands. PNA exhibited good fluorescence recognition for l- and d-proline (Pro). Homochiral interaction led to fluorescence enhancement, while heterochiral interaction led to fluorescence quenching, and there is a good linear relationship between the fluorescence changing rate and l- or d-Pro concentration. Mechanism studies show that homochiral interaction-induced fluorescence enhancement is attributed to the disassembly of chiral PNA, while no disassembly of chiral PNA was found in heterochiral interaction-induced fluorescence quenching, which is attributed to the substitution of Phe on the surface of chiral PNA by heterochiral Pro. This work suggests that chiral perovskite can be used for chiral fluorescence sensing; it will inspire the development of chiral nanomaterials and chiral optical sensors.

5.
Anal Chem ; 96(11): 4597-4604, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38456210

ABSTRACT

DNA assemblies are commonly used in biosensing, particularly for the detection and imaging of microRNAs (miRNAs), which are biomarkers associated with tumor progression. However, the difficulty lies in the exploration of high-sensitivity analytical techniques for miRNA due to its limited presence in living cells. In this study, we introduced a DNA nanosphere (DS) enhanced catalytic hairpin assembly (CHA) system for the detection and imaging of intracellular miR-21. The single-stranded DNA with four palindromic portions and extending sequences at the terminal was annealed for assembling DS, which avoided the complex sequence design and high cost of long DNA strands. Benefiting from the multiple modification sites of DS, functional hairpins H1 (modified with Cy3 and BHQ2) and H2 were grafted onto the surface of DS for assembling DS-H1-H2 using a hybridization reaction. The DS-H1-H2 system utilized spatial confinement and the CHA reaction to amplify fluorescence signals of Cy3. This enabled highly sensitive and rapid detection of miR-21 in the range from 0.05 to 3.5 nM. The system achieved a limit of determination (LOD) of 2.0 pM, which was 56 times lower than that of the control CHA circuit with freedom hairpins. Additionally, the sensitivity was improved by 8 times. Moreover, DS-H1-H2 also showed an excellent imaging capability for endogenous miR-21 in tumor cells. This was due to enhanced cell internalization efficiency, accelerated reaction kinetics, and improved biostability. The imaging strategy was shown to effectively monitor the dynamic content of miR-21 in live cancer cells and differentiate various cells. In general, the simple nanostructure DS not only enhanced the detection and imaging capability of the conventional probe but also could be easily integrated with the reported DNA-free probe, indicating a wide range of potential applications.


Subject(s)
Biosensing Techniques , DNA, Catalytic , MicroRNAs , Nanospheres , Neoplasms , MicroRNAs/genetics , MicroRNAs/chemistry , DNA/genetics , DNA/chemistry , Nucleic Acid Hybridization , DNA Probes/chemistry , Biosensing Techniques/methods , Limit of Detection
6.
Anal Sci ; 40(3): 511-518, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38151695

ABSTRACT

Real-time monitoring of hypochlorous acid (HClO) in biological systems is of great significance for exploring and regulating its pathological functions because abnormal production of HClO is closely related with many diseases, such as atherosclerosis, rheumatoid arthritis, and cancer. Herein, we developed a reliable fluorescent Fe-doped carbon dots (Fe-CDs) for the sensitive and selective detection of biological HClO using ferrocenecarboxylic acid and m-phenylenediamine as precursors through a one-step solvothermal procedure. The Fe-CDs exhibited excellent a wide HClO detection range from 20 nmol/L to 1000 nmol/L with corresponding limits of detection at 7.8 nmol/L. The sensing mechanism is based on the chemical oxidation of the hydroxyl groups on the surface of Fe-CDs by HClO. In addition, Fe-CDs also displayed high photoluminescence yield, excitation-independence emission, as well as good biocompatibility, enabling the successful imaging of endogenous and exogenous HClO in HeLa cells. These results revealed that Fe-CDs holds great promise as a robust fluorescent probe for investigating HClO-mediated biological events.


Subject(s)
Hypochlorous Acid , Quantum Dots , Humans , HeLa Cells , Carbon , Fluorescent Dyes
7.
Anal Chem ; 95(41): 15375-15383, 2023 Oct 17.
Article in English | MEDLINE | ID: mdl-37796610

ABSTRACT

Single particle analysis can effectively determine the heterogeneity between particles based on the local information on a single particle, which is utilized extensively for monitoring chemical reactions and biological activities. However, the study of obtaining ensemble reaction information at the single particle level, which can obtain both the structural and functional heterogeneity of particles as well as the ensemble reaction information, is challenging because the selection of a single particle mainly depends on experience, which will lead to a certain randomness when analyzing the ensemble reaction with single particles. Using machine learning, it is demonstrated that the proposed intelligent single particle analysis strategy can provide single particle and ensemble analyses with high confidence. Convolutional neural network and Gaussian mixture model were utilized to develop a machine learning model for resonance scattering imaging analysis of plasmonic nanoparticles. It can identify the scattered light of single particles and select representative or diverse particles. When single particle scattering imaging is used to obtain ensemble information on the reaction, the error caused by the selection of individual particles can be significantly reduced by selecting representative particles. In addition, the real situation of the reaction can be better revealed by selecting diverse particles. These results indicate that the intelligent single particle analysis strategy has great potential for imaging analysis and biological sensing.

8.
J Am Chem Soc ; 145(36): 19503-19507, 2023 09 13.
Article in English | MEDLINE | ID: mdl-37638713

ABSTRACT

Tile-based DNA self-assembly provides a versatile approach for the construction of a wide range of nanostructures for various applications such as nanomedicine and advanced materials. The inter-tile interactions are primarily programmed by base pairing, particularly Watson-Crick base pairing. To further expand the tool box for DNA nanotechnology, herein, we have designed DNA tiles that contain both ligands and aptamers. Upon ligand-aptamer binding, tiles associate into geometrically well-defined nanostructures. This strategy has been demonstrated by the assembly of a series of DNA nanostructures, which have been thoroughly characterized by gel electrophoresis and atomic force microscopy. This new inter-tile cohesion could bring new potentials to DNA self-assembly in the future. For example, the addition of free ligand could modulate the nanostructure formation. In the case of biological ligands, DNA self-assembly could be related to the presence of certain ligands.


Subject(s)
DNA , Oligonucleotides , Ligands , Base Pairing , Microscopy, Atomic Force
9.
Sci Adv ; 9(34): eadg9601, 2023 08 25.
Article in English | MEDLINE | ID: mdl-37624881

ABSTRACT

The dearth of antibiotic candidates against Gram-negative bacteria and the rise of antibiotic resistance create a global health concern. The challenge lies in the unique Gram-negative bacterial outer membrane that provides the impermeable barrier for antibiotics and sequesters antigen presentation. We designed a transformable nano-antibiotics (TNA) that can transform from nontoxic nanoparticles to bactericidal nanofibrils with reasonable rigidity (Young's modulus, 21.6 ± 5.9 MPa) after targeting ß-barrel assembly machine A (BamA) and lipid polysaccharides (LPSs) of Gram-negative bacteria. After morphological transformation, the TNA can penetrate and damage the bacterial envelope, disrupt electron transport and multiple conserved biosynthetic and metabolic pathways, burst bacterial antigen release from the outer membrane, and subsequently activate the innate and adaptive immunity. TNA kills Gram-negative bacteria in vitro and in vivo with undetectable resistance through multiple bactericidal modes of action. TNA treatment-induced vaccination results in rapid and long-lasting immune responses, protecting against lethal reinfections.


Subject(s)
Anti-Bacterial Agents , Gram-Negative Bacteria , Anti-Bacterial Agents/pharmacology , Antigen Presentation , Antigens, Bacterial , Elastic Modulus
10.
Anal Chim Acta ; 1276: 341651, 2023 Oct 02.
Article in English | MEDLINE | ID: mdl-37573127

ABSTRACT

There are more than 200 subtypes of human papillomavirus (HPV), and high-risk HPVs are a leading cause of cervical cancer. Identifying the genotypes of HPV is significant for clinical diagnosis and cancer control. Herein, we used programmable and modified DNA as the backbone to construct fluorescent genotyping nanodevice for HPV subtype distinction. In our strategy, the dye-labeled single-stranded recognize-DNA (R-DNA) was hybridized with Black Hole Quencher (BHQ) labeled single-stranded link-DNA (L-DNA) to form three functionalized DNA (RL-DNA). Through the extension of polycytosine (poly-C) in L-DNA, three RL-DNAs can be more firmly adsorbed on graphene oxide to construct reliable genotyping nanodevice. The genotyping nanodevice had low background noise since the dual energy transfer, including Förster resonance energy transfer (FRET) from dye to BHQ and the resonance energy transfer (RET) from dye to graphene oxide. Meanwhile, the programmability of DNA allows the proposed strategy to simultaneously and selectively distinguish several HPV subtypes in solution using DNA labeled with different dyes. To demonstrate clinical potential, we show multiplexed assay of HPV subtypes in cervical scrapes, and it has been successfully applied in HPV-DNA analysis in cervical scrapes samples. The genotyping nanodevice could be developed for simultaneous and multiplex analysis of several oligonucleotides in a homogeneous solution by adjusting the recognition sequence, demonstrating its potential application in the rapid screening of multiple biomarkers.


Subject(s)
Papillomavirus Infections , Uterine Cervical Neoplasms , Female , Humans , Genotype , Human Papillomavirus Viruses , Papillomavirus Infections/diagnosis , Papillomaviridae/genetics , Uterine Cervical Neoplasms/diagnosis , DNA, Viral/genetics , DNA, Viral/analysis
11.
Anal Chem ; 95(29): 10992-10998, 2023 07 25.
Article in English | MEDLINE | ID: mdl-37436093

ABSTRACT

Challenges remained in precisely real-time monitoring of apoptotic molecular events at the subcellular level. Herein, we developed a new type of intelligent DNA biocomputing nanodevices (iDBNs) that responded to mitochondrial microRNA-21 (miR-21) and microRNA-10b (miR-10b) simultaneously which were produced during cell apoptosis. By hybridizing two hairpins (H1 and H2) onto DNA nanospheres (DNSs) that had been previously modified with mitochondria-targeted triphenylphosphine (TPP) motifs, iDBNs were assembled in which two localized catalytic hairpins self-assembly (CHA) reactions occurred upon the co-stimulation of mitochondrial miR-21 and miR-10b to perform AND logic operations, outputting fluorescence resonance energy transfer (FRET) signals for sensitive intracellular imaging during cell apoptosis. Owing to the spatial confinement effects of DNSs, it was discovered that iDBNs had a high efficiency and speed of logic operations by high local concentrations of H1 and H2, making the simultaneous real-time responses of mitochondrial miR-21 and miR-10b reliable and sensitive during cell apoptosis. These results demonstrated that iDBNs were simultaneously responsive to multiple biomarkers, which greatly improved the detection accuracy to identify the cell apoptosis, demonstrating that iDBNs are highly effective and reliable for the diagnosis of major disease and screening of anticancer drugs.


Subject(s)
MicroRNAs , MicroRNAs/genetics , DNA , Apoptosis , Biomarkers
12.
Anal Chem ; 95(26): 9754-9760, 2023 07 04.
Article in English | MEDLINE | ID: mdl-37343019

ABSTRACT

De novo design of functional biomacromolecules is of great interest to a wide range of fundamental science and technological applications, including understanding life evolution and biomacromolecular structures, developing novel catalysts, inventing medicines, and exploring high-performance materials. However, it is an extremely challenging task and its success is very limited. It requires a deep understanding of the relationships among the primary sequences, the 3D structures, and the functions of biomacromolecules. Herein, we report a rational, de novo design of a DNA aptamer that can bind melamine with high specificity and high affinity (dissociation constant Kd = 4.4 nM). The aptamer is essentially a DNA triplex, but contains an abasic site, to which the melamine binds. The aptamer-ligand recognition involves hydrogen-bonding, π-π stacking, and electrostatic interactions. This strategy has been further tested by designing aptamers to bind to guanosine. It is conceivable that such a rational strategy, with further development, would provide a general framework for designing functional DNA molecules.


Subject(s)
Aptamers, Nucleotide , DNA , DNA/chemistry , Aptamers, Nucleotide/chemistry , Hydrogen Bonding
13.
ACS Appl Mater Interfaces ; 15(27): 32262-32271, 2023 Jul 12.
Article in English | MEDLINE | ID: mdl-37341517

ABSTRACT

Polyvalent ligand-induced cell receptor aggregation is closely related to cell behavior regulation. At present, most of the means to induce receptor aggregation rely on external stimuli such as light, heat, and magnetic fields, which may cause side effects to normal cells. How to achieve receptor aggregation on the cancer cell surface to achieve cell apoptosis selectively is still a challenge. Therefore, by taking advantage of the unique property of cancer cells' slightly acidic microenvironment, an easy-to-use apoptosis-inducing mode for the in situ activation of cell surface nucleolin clustering has been developed, which not only opened a new channel for nucleolin receptor aggregation to regulate cell function and further development but also avoided damage to normal cells, providing a new strategy for tumor treatment. Dual functional ssDNA (AS1411 aptamer and pH-responsive I-strand sequence) was modified on the surface of gold nanoparticles (AuNPs) to fabricate AI-Au intelligent nanomachines. Then, the specific binding on cancer cells and aggregation of the nucleolin receptors can be achieved via the formation of an i-Motif structure among adjacent AuNPs under the acidic microenvironment. The result showed that AI-Au nanomachines mediated nucleolin cross-linking on the cell surface, resulting in a cytotoxic effect of approximately 60%. Experiments such as calcein-AM/PI staining, nuclear dye staining, and flow cytometry demonstrated that cell apoptosis became more evident with the increase of acidity under the cell surface microenvironment. Immunofluorescence imaging further confirmed the Cyt-c/caspase-3 apoptosis pathway induced by AI-Au nanomachines. The proposed strategy used for specific cancer cell apoptosis by the in situ activation of tumor cell membrane receptor aggregation is inexpensive and simple to use, which not only provides a new means of nucleolin receptor aggregation for regulating cell function but also offers a new strategy for tumor treatment with reduced side effect to normal cells. This work is significant for comprehending the ligand-induced receptor aggregation process and can lead to the development of a promising anticancer drug.


Subject(s)
Antineoplastic Agents , Aptamers, Nucleotide , Metal Nanoparticles , Neoplasms , Humans , Gold/pharmacology , Gold/chemistry , Ligands , Apoptosis , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Neoplasms/drug therapy , Receptor Aggregation , Cell Line, Tumor , Aptamers, Nucleotide/pharmacology , Tumor Microenvironment
14.
Anal Chem ; 95(19): 7603-7610, 2023 05 16.
Article in English | MEDLINE | ID: mdl-37129512

ABSTRACT

System leakage critically confines the development of cascade DNA systems that need to be implemented in a strict order-by-order manner. In principle, ternary DNA reactants, composed of three single-strand DNA (ssDNA) with a strict equimolar ratio (1:1:1), have been indispensable for successfully cascading upstream entropy-driven DNA circuit (EDC) with downstream circuits, and system leakage will occur with any unbalance of the molar ratio. In this work, we proposed "splitting-reconstruction" and "protection-release" strategies on the potential downstream circuit initiator derived from upstream EDC to guide the construction of EDC-involved cascade systems independent of system leakage derived from unpurified reactants. Both the reconstructed and released downstream circuit initiators were in compliance with the principle of the cascade AND logic gate. Using these two strategies, two cascade systems─EDC2-4WJ-TMSDR and EDC3-HCR─were developed to carry out the designed order, which did not require that the ratio of 1:1:1 be maintained. Furthermore, the inherent property of the upstream EDC could transfer into the downstream circuit, endowing the developed cascade systems with a more powerful signal amplification ability for the sensitive detection of the corresponding initiator strand. These two strategies may provide new insights into the process of constructing EDC-like circuit-involved high-order DNA networks.


Subject(s)
DNA, Single-Stranded , DNA , DNA/genetics , DNA, Single-Stranded/genetics , Entropy , Logic
15.
Chem Commun (Camb) ; 59(38): 5729-5732, 2023 May 09.
Article in English | MEDLINE | ID: mdl-37092322

ABSTRACT

Understanding the structural transformation of photocatalysts under illumination provides detailed insights to solve the poisoning of photocatalysts. In this study, the 1O2-induced transformation of crystalline structure in nanosized Zr-porphyrin metal organic frames (ZrTCPP MOFs) is confirmed by a dark-field microscopy (DFM) system. Under continuous illumination, the energy of excited ZrTCPP transfers to oxygen in the surroundings and generates 1O2, which causes the nanosized crystal ZrTCPP to change into the amorphous state The crystalline structure of ZrTCPP corresponds to the multiple resonance peaks of the scattering spectra, and the amorphous structure corresponds to the single scattering peak. Therefore, the crystalline change is characterized by characteristic peaks changes in the scattering spectra under DFM, showing that a real-time and in situ DFM imaging method is a good platform for monitoring the crystal structure transformation at the single particle level.

16.
Acta Biomater ; 164: 387-396, 2023 07 01.
Article in English | MEDLINE | ID: mdl-37088158

ABSTRACT

Short peptides are poor immunogens. One way to increase their immune responses is by arraying immunogens in multivalency. Simple and efficient scaffolds for spatial controlling the inter-antigen distance and enhancing immune activation are required. Here, we report a molecular vaccine design principle that maximally drives potent SARS-CoV-2 RBD subunit vaccine on DNA duplex to induce robust and efficacious immune responses in vivo. We expect that the DNA-peptide epitope platform represents a facile and generalizable strategy to enhance the immune response. STATEMENT OF SIGNIFICANCE: DNA scaffolds offer a biocompatible and convenient platform for arraying immunogens in multivalency antigenic peptides, and spatially control the inter-antigen distance. This can effectively enhance immune response. Peptide (instead of entire protein) vaccines are highly attractive. However, short peptides are poor immunogens. Our DNA scaffolded multivalent peptide immunogen system induced robust and efficacious immune response in vivo as demonstrated by the antigenic peptide against SARS-CoV-2. The present strategy could be readily generalized and adapted to prepare multivalent vaccines against other viruses or disease. Particularly, the different antigens could be integrated into one single vaccine and lead to super-vaccines that can protect the host from multiple different viruses or multiple variants of the same virus.


Subject(s)
COVID-19 , Vaccines , Humans , COVID-19 Vaccines/pharmacology , SARS-CoV-2 , Vaccines, Combined , COVID-19/prevention & control , Peptides , DNA
17.
Anal Chem ; 95(18): 7237-7243, 2023 05 09.
Article in English | MEDLINE | ID: mdl-37120835

ABSTRACT

DNA nanosheets (DNSs) have been utilized effectively as a fluorescence anisotropy (FA) amplifier for biosensing. But, their sensitivity needs to be further improved. Herein, CRISPR-Cas12a with strong trans-cleavage activity was utilized to enhance the FA amplification ability of DNSs for the sensitive detection of miRNA-155 (miR-155) as a proof-of-principle target. In this method, the hybrid of the recognition probe of miR-155 (T1) and a blocker sequence (T2) was immobilized on the surface of magnetic beads (MBs). In the presence of miR-155, T2 was released by a strand displacement reaction, which activated the trans-cleavage activity of CRISPR-Cas12a. The single-stranded DNA (ssDNA) probe modified with a carboxytetramethylrhodamine (TAMRA) fluorophore was cleaved in large quantities and could not bind to the handle chain on DNSs, inducing a low FA value. In contrast, in the absence of miR-155, T2 could not be released and the trans-cleavage activity of CRISPR-Cas12a could not be activated. The TAMRA-modified ssDNA probe remained intact and was complementary to the handle chain on the DNSs, and a high FA value was obtained. Thus, miR-155 was detected through the obviously decreased FA value with a low limit of detection (LOD) of 40 pM. Impressively, the sensitivity of this method was greatly improved about 322 times by CRISPR-Cas12a, confirming the amazing signal amplification ability of CRISPR-Cas12a. At the same time, the SARS-CoV-2 nucleocapsid protein was detected by the strategy successfully, indicating that this method was general. Moreover, this method has been applied in the analysis of miR-155 in human serum and the lysates of cells, which provides a new avenue for the sensitive determination of biomarkers in biochemical research and disease diagnosis.


Subject(s)
Biosensing Techniques , COVID-19 , MicroRNAs , Humans , SARS-CoV-2 , DNA , DNA, Single-Stranded , CRISPR-Cas Systems/genetics
18.
Anal Methods ; 15(12): 1500-1505, 2023 03 23.
Article in English | MEDLINE | ID: mdl-36916642

ABSTRACT

In this study, molecularly imprinted polymers (MIPs) were assembled on the surface of ethylene imine polymer (PEI)/poly(vinyl alcohol) (PVA) electrospun nanofiber membranes for the point-of-care testing (POCT) of thiodiglycol (TDG), a sulfur mustard poisoning metabolic marker, using concentrated gold nanoparticles (AuNPs) as the signal reporting units. The MIPs/PEI/PVA nanofiber membranes could capture TDG specifically through the recognition interaction between MIPs and TDG. Then, AuNPs were adsorbed onto the MIPs/PEI/PVA nanofiber membranes through the Au-S interaction between TDG and AuNPs to produce a visible red color. In order to improve the sensitivity, the silver-enhanced solutions were used to deepen the color of the nanofiber membranes and the software Image J was used to read the gray value as the signal response for subsequent analysis. There was a good linear relationship between the color change of the MIPs/PEI/PVA nanofiber membranes and the TDG concentration from 0.1 ng mL-1 to 1.0 µg mL-1, and the limit of detection was 38 pg mL-1. This method was applied for the selective detection of TDG in urine, showing great potential for the clinical diagnosis of mustard gas poisoning.


Subject(s)
Metal Nanoparticles , Mustard Gas , Nanofibers , Molecularly Imprinted Polymers , Gold , Point-of-Care Systems , Static Electricity
19.
Anal Chem ; 95(8): 3968-3975, 2023 02 28.
Article in English | MEDLINE | ID: mdl-36792543

ABSTRACT

Multiple biomarker detection is crucial for early clinical diagnosis, and it is significant to achieve the simultaneous detection of multiple biomarkers with the same nanomaterial. In this work, the hairpin DNA strands were selectively modified on the surface of gold nanorods (AuNRs) to construct two kinds of nanoprobes by rational design. When in the presence of dual microRNAs, AuNRs were assembled to form end-to-end (ETE) and side-by-side (SBS) dimers. Compared with a single AuNR, the dark-field scattering intensity and red color percentage variation of dimers were extremely distinguished, which could be developed for dual microRNA detection by combining the red color percentage and scattering intensity with the data processing method of principal component analysis to construct a two-dimensional analysis method. Especially, the fraction of AuNR dimers presented a linear relationship with the amount of microRNAs. Based on this, microRNA-21 and microRNA Let-7a in breast cancer cells were detected with the detection limits of 1.72 and 0.53 fM, respectively. This method not only achieved the sensitive detection of dual microRNAs in human serum but also realized the high-resolution intracellular imaging, which developed a new way for the oriented assembly of nanomaterials and biological detection in living cells.


Subject(s)
Biosensing Techniques , Breast Neoplasms , Metal Nanoparticles , MicroRNAs , Nanotubes , Humans , Female , MicroRNAs/analysis , Breast Neoplasms/genetics , DNA , Biomarkers , Gold , Limit of Detection
20.
Anal Chem ; 2023 Jan 12.
Article in English | MEDLINE | ID: mdl-36633481

ABSTRACT

Owing to the excellent structural rigidity and programmable reaction sites, DNA nanostructures are more and more widely used, but they are limited by high cost, strict sequence requirements, and time-consuming preparation. Herein, a general signal amplifier based on a micelle-supported entropy-driven circuit (MEDC) was designed and prepared for sensitive quantification of biomarkers. By modifying a hydrophobic cholesterol molecule onto a hydrophilic DNA strand, the amphiphilic DNA strand was first prepared and then self-assembled into DNA micelles (DMs) driven by hydrophobic effects. The as-developed DM showed unique advantages of sequence-independence, easy preparation, and low cost. Subsequently, amplifier units DMF and DMTD were successfully fabricated by connecting fuel strands and three-strand duplexes (TDs) to DMs, respectively. Finally, the MEDC was triggered by microRNA-155 (miR-155), which herein acted as a model analyte, resulting in dynamic self-assembly of poly-DNA micelles (PDMs) and causing the recovery of cyanine 3 (Cy3) fluorescence as the DMTD dissociated. Benefiting from the "diffusion effect", the MEDC herein had a nearly 2.9-fold increase in sensitivity and a nearly 97-fold reduction in detection limit compared to conventional EDC. This amplifier exhibited excellent sensitivity of microRNAs, such as miR-155 detection in a dynamic range from 0.05 to 4 nM with a detection limit of 3.1 pM, and demonstrated outstanding selectivity with the distinguishing ability of a single-base mismatched sequence of microRNAs. Overall, the proposed strategy demonstrated that this sequence-independent DNA nanostructure improved the performance of traditional DNA probes and provided a versatile method for the development of DNA nanotechnology in biosensing.

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