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Y-shaped DNA-Mediated hybrid nanoflowers as efficient gene carriers for fluorescence imaging of tumor-related mRNA in living cells
摘要： Organic-inorganic hybrid nanomaterial has gained much attention due to its excellent performances in bioanalysis and biomedicine. However, the preparation of DNA-inorganic hybrid nanomaterial with suitable size for cell uptake remains a huge challenge. Herein, a moderate biomineralization strategy for synthesis of Y-DNA@Cu3(PO4)2 (Y-DNA@CuP) hybrid nanoflowers is reported. Y-DNA with a loop structure is used as both the biomineralization template and the recognition unit for thymidine kinase 1 (TK1) mRNA. The Y-DNA probe can linearly response to TK1 mRNA target sequence in a range from 2 nM to 150 nM with the limit of detection as low as 0.56 nM. Interestingly, the presence of Y-DNA significantly decreases the size of Cu3(PO4)2 (CuP) particles, which allows them suitable for intracellular applications as gene nanocarriers. Once inside the cells, the hybrid nanoflowers dissolve and release the Y-DNA probes. Then, the intracellular TK1 mRNA hybridizes with the loop region of Y-DNA, which dissociates the Cy3-labeled loop strand and turns on the red fluorescence. Through the real-time imaging of the intracellular TK1 mRNA, the assessment of tumor cells before and after the treatment of drugs including b-estradiol and tamoxifen is achieved.
关键词： Cell imaging,Thymidine kinase 1,Biomineralization,Y-shaped DNA@CuP,Tumor-related biomarker
更新于2025-09-19 17:15:36
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Protein-functionalized WO3 nanorods–based impedimetric platform for sensitive and label-free detection of a cardiac biomarker
摘要： We report the development of a sensitive and a label-free electrochemical immunosensing platform for the detection of cardiac biomarker troponin I (cTnI) using tungsten trioxide nanorods (WO3 NRs). The low-temperature hydrothermal technique was employed for the controlled synthesis of WO3 NRs. Thin films of 3-aminopropyltriethoxy saline (APTES)-functionalized WO3 NRs were deposited on indium tin oxide (ITO)-coated glass substrate (0.5 cm × 1 cm) using electrophoretic deposition technique. The covalent immobilization of cTnI antibody onto functionalized WO3 NRs electrode was accomplished using EDC-NHS [1-(3-(dimethylamino)-propyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysulfosuccinimide] chemistry. The structural and morphological characterizations of WO3 NRs and functionalized WO3 NRs were studied using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and electrochemical techniques. The impedimetric response study of the proposed immunosensor demonstrates high sensitivity [6.81 KΩ·mL/(ng·cm2)] in a linear detection range of 0.01–10 ng/mL. The excellent selectivity, good reproducibility, and long-term stability of the proposed immunosensing platform indicate WO3 NRs as a suitable platform for the development of a point-of-care biosensing device for cardiac detection.
关键词： electrochemical impedance spectroscopy,tungsten trioxide nanorods,immunosensor,cardiac biomarker,label-free detection
更新于2025-09-19 17:15:36
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Graphene Quantum Dot-Based Nanocomposites for Diagnosing Cancer Biomarker APE1 in Living Cells
摘要： As an essential DNA repair enzyme, apurinic/apyrimidinic endonuclease 1 (APE1) is overexpressed in most human cancers and is identified as a cancer diagnostic and predictive biomarker for cancer risk assessment, diagnosis, prognosis and prediction of treatment efficacy. Despite its importance in cancer, however, it is still a significant challenge nowadays to sense abundance variation and monitor enzymatic activity of this biomarker in living cells. Here, we report our construction of biocompatible functional nanocomposites, which are a combination of meticulously designed unimolecular DNA and fine-sized graphene quantum dots. Upon utilization of these nanocomposites as diagnostic probes, massive accumulation of fluorescence signal in living cells can be triggered by merely a small amount of cellular APE1 through repeated cycles of enzymatic catalysis. Most critically, our delicate structural designs assure that these graphene quantum dot-based nanocomposites are capable of sensing cancer biomarker APE1 in identical type of cells under different cell conditions and can be applied to multiple cancerous cells in highly sensitive and specific manners. This work not only brings about new methods for cytology-based cancer screening, but also lays down a general principle for fabricating diagnostic probes that target other endogenous biomarkers in living cells.
关键词： cancer diagnosis,biomarker,nanocomposites,DNA repair enzymes,graphene quantum dots
更新于2025-09-19 17:13:59
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Combining laser microdissection and microRNA expression profiling to unmask microRNA signatures in complex tissues
摘要： Neglecting tissue heterogeneity during the analysis of microRNA (miRNA) levels results in average signals from an unknown mixture of different cell types that are difficult to interpret. Here we demonstrate the technical requirements needed to obtain high-quality, quantitative miRNA expression information from tumor tissue compartments obtained by laser microdissection (LMD). Furthermore, we show the significance of disentangling tumor tissue heterogeneity by applying the newly developed protocols for combining LMD of tumor tissue compartments with RT-qPCR analysis to reveal compartment-specific miRNA expression signatures. An important advantage of this strategy is that the miRNA signature can be directly linked to histopathology. In summary, combining LMD and RT-qPCR is a powerful approach for spatial miRNA expression analysis in complex tissues, enabling discovery of disease mechanisms, biomarkers and drug candidates.
关键词： laser microdissection (LMD),biomarker discovery,tumor microenvironment,drug discovery,microRNA profiling,tissue complexity
更新于2025-09-19 17:13:59
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Label-free quantum dot conjugates for human protein IL-2 based on molecularly imprinted polymers
摘要： Herein, the development of a fluorescent-based sensor by combining quantum dots (QDs) with molecularly-imprinted technology (MIP), intensively optimized to generate exceptional operating features is presented. This sensor is designed to target human interleukin-2 (IL-2) in synthetic human serum. IL-2 is a regulatory protein released as a triggered response from the immune system towards an inflammation. For this purpose, cadmium telluride (CdTe) QDs are prepared with 3-mercaptopropionic acid (MPA) and modified afterwards to produce an IL-2 imprinted polymer with methacrylic acid and N,N′-methylenebis(acrylamide), upon removal of the template under optimized conditions. During IL-2 rebinding, the fluorescence intensity of CdTe@MPA QDs is quenched in a concentration dependent manner. Using surface imprinting technology, the optimal fluorescence signals yielded a linear response versus logarithm of IL-2 concentration from 35 fg/ml to 39 pg/ml, in a 1000-fold diluted synthetic human serum. The limit of detection obtained is 5.91 fg/ml, lying below the concentration levels of IL-2 with clinical interest for cancer diagnosis (9.4-19.2 pg/ml). Overall, the method presented herein is a demonstration that the combination of MIP and QDs for protein detection constitutes a powerful tool in clinical analysis, providing low cost, sensitive and quick responses. The same concept may be further extended to other proteins of interest.
关键词： interleukin-2,conjugated-QDs,protein,molecularly imprinted polymer,Quantum dots,cancer biomarker
更新于2025-09-16 10:30:52
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Plasmon-Emitter Hybrid Nanostructures of Gold Nanorod-Quantum Dots with Regulated Energy Transfer as a Universal Nano-Sensor for One-step Biomarker Detection
摘要： Recently, biosensing based on weak coupling in plasmon-emitter hybrid nanostructures exhibits the merits of simplicity and high sensitivity, and attracts increasing attention as an emerging nano-sensor. In this study, we propose an innovative plasmon-regulated fluorescence resonance energy transfer (plasmon-regulated FRET) sensing strategy based on a plasmon-emitter hybrid nanostructure of gold nanorod-quantum dots (Au NR-QDs) by partially modifying QDs onto the surfaces of Au NRs. The Au NR-QDs showed good sensitivity and reversibility against refractive index change. We successfully employed the Au NR-QDs to fabricate nano-sensors for detecting a cancer biomarker of alpha fetoprotein with a limit of detection of 0.30 ng/mL, which displays that the sensitivity of the Au NR-QDs nano-sensor was effectively improved compared with the Au NRs based plasmonic sensing. Additionally, to demonstrate the universality of the plasmon-regulated FRET sensing strategy, another plasmon-emitter hybrid nano-sensor of Au nano-prism-quantum dots (Au NP-QDs) were constructed and applied for detecting a myocardial infarction biomarker of cardiac troponin I. It was first reported that the change of absorption spectra of plasmonic structure in a plasmon-emitter hybrid nanostructure was employed for analytes detection. The plasmon-regulated FRET sensing strategy described herein has potential utility to develop general sensing platforms for chemical and biological analysis.
关键词： localized surface plasmon resonance,quantum dot,gold nanorod,biomarker,fluorescence resonance energy transfer,plasmonic-emitter hybrid nanostructure
更新于2025-09-16 10:30:52
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Electrochemiluminescence Resonance Energy Transfer between Ru(bpy) <sub/>3</sub><sup>2+</sup> and CdZnSe@ZnSe Quantum Dots for Ovarian Cancer Biomarker Detection
摘要： Herein, an enhanced electrochemiluminescence resonance energy transfer (ECL-RET) from Ru(bpy)3 2+ to the core/shell CdZnSe@ZnSe quantum dots (CdZnSe@ZnSe QDs) was first designed for ovarian cancer biomarker analysis. The TiO2 metal-organic frameworks (TiO2 MOFs) was used as promoter because of its unique semiconductor structure and high loading ability for Ru(bpy)3 2+. Additionally, Envision complex with numerous horseradish peroxidase (HRP) was employed to immobilize CdZnSe@ZnSe QDs, the acceptor of ECL-RET, which further improved the ECL emission of CdZnSe@ZnSe QDs. Concretely, reactive oxygen species (ROS), for instance, O2 ?? and OH?, were firstly yielded due to the catalytic ability of HRP to H2O2, and then the electron from O2 ?? or hole from OH? injection into the CdZnSe@ZnSe QDs, triggering an extremely strong ECL response of CdZnSe@ZnSe QDs. On the basis of all above features, a highly effective ECL-RET biosensor was elaborately established to detect the targets in the range of 1.00×10-6?1.00×102 ng/mL with low detection limit of 3.30×10-1 fg/mL (S/N=3). This work opened up a new avenue for developing high-performance ECL-RET biosensors and demonstrated the high potential of the new biomarker in clinical ovarian cancer screening.
关键词： CdZnSe@ZnSe QDs,TiO2 MOFs,Envision complex,ECL-RET,ovarian cancer biomarker
更新于2025-09-12 10:27:22
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A turn-on graphene quantum dot and graphene oxide based fluorometric aptasensor for the determination of telomerase activity
摘要： A turn-on fluorometric assay is described for determination of the activity of enzyme telomerase. For this purpose, graphene quantum dots (GQDs) were first modified with the telomeric sequence (5′-amino-AATCCGTCGAGCAGAGTT-3′) via a condensation reaction. Injection of graphene oxide causes instant quenching of the blue fluorescence of the GQDs. Addition of cell extract containing telomerase, triggers the extension of telomer via addition of specific sequence (TTAGGG)n to its 3′ end. Fluorescence, best measured at excitation/emission wavelengths of 390/446 nm, is subsequently restored due to folding of the extended telomeric sequence into G-quadruplex structure. The method was applied to the determination of telomerase activity in crude cell extracts of as little as 10 HeLa cells. The linear dynamic range extends from 10 to 6500 cells.
关键词： G-quadruplex,Biosensors,Fluorescence,Optical sensing,Biomarker,Cancer detection,Nanoprobe
更新于2025-09-12 10:27:22
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A boronate-modified molecularly imprinted polymer labeled with a SERS-tag for use in an antibody-free immunoassay for the?carcinoembryonic antigen
摘要： An antibody-free immunoassay that makes use of a boronate affinity molecularly imprinted polymer (MIP) and surface enhanced Raman scattering (SERS) tags is described. It was applied to the specific determination of the carcinoembryonic antigen (CEA) in human serum. For the preparation of the boronate affinity array, a polymer capable of adsorbing glycoproteins was first synthesized on the surface of a glass slide with four spots using 4-vinylbenzeneboronic acid (VPBA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the crosslinking agent, and ethylene glycol and cyclohexanol as porogens. The surface of the VPBA-Co-EGDMA can bind target glycoproteins. After specific capture of the glycoprotein, a “MIP-target glycoprotein-SERS tag” sandwich structure was formed by covalent interaction between the SERS nanotag (consisting of gold nanoparticles and 4-mercaptophenylboronic acid [MPBA]). CEA can be quantified in spiked serum with a detection limit of 0.1 ng·mL?1 via the specific Raman band at 1098 cm?1.
关键词： MIP array,Sandwich structure,Nanoprobes,Biomarker,Real sample analysis
更新于2025-09-12 10:27:22
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Biosynthesized Quantum Dot for Facile and Ultrasensitive Electrochemical and Electrochemiluminescence Immunoassay
摘要： Nanomaterials are commonly utilized for amplified immunoassay of biomarkers. However, traditional nanomaterial-based immunoassay usually requires time-consuming and labor-intensive nanoparticle modification and conjugation process, which impedes their practical applications. Here, a new immunoassay method based on biosynthesized nanomaterials is developed with versatile functions for facile and ultrasensitive detection of cancer biomarker. In this method, the utilized biosynthesized quantum dots (BQDs) allow convenient antibody conjugation and electrode modification, and demonstrate excellent electrochemical and electrochemiluminescent responses. The differential pulse voltammetric, impedance spectroscopy, and electrochemiluminescent measurements with the BQD-modified electrode show detection limits at picomolar levels as well as good specificity towards human prostate-specific antigen (PSA) detection. The inherent recognization capability as well as the inherent electrochemical and electrochemiluminescence features thus enable BQDs good candidates for facile immunosensors with high sensitivity. Such a biosynthesized nanomaterial-based approach opens up the possibility of using innovative designs for nanoparticle-based assays, and developing reliable and practical methods for early disease diagnosis.
关键词： Biosynthesized quantum dots,Immunoassay,Electrochemical,Electrochemiluminescence,Cancer biomarker
更新于2025-09-11 14:15:04