Gilliamelgaard2559

The HRCA-strip platform could achieve highly sensitive and specific miRNA 31 detection with the limit of detection (LOD) as low as 3.21 fM. Moreover, the designed HRCA-strip platform also enabled portable detection of miRNA 31 in clinical sample which might show good potential for early clinical diagnosis of OSCC.The aggregation and redispersion of positively-charged AuNPs ((+)AuNPs) modified with cysteamine (CS) could be regulated by the negatively charged As(III)-specific aptamer (As(III)-apt). In general, (+)AuNPs aggregated with increasing inducer concentration. However, in the present study, it was found that (+)AuNPs re-dispersed after a certain high concentration of As(III)-apt was reached. this website By optimizing the concentration of As(III)-apt that resulted in the aggregation and redispersion behavior of (+)AuNPs, a dual-mode colorimetric aptasensor for As(III) determination was established. It was not only able to quantify As(III) sensitively over a ranges of As(III) concentrations, but also to selectively differentiate As(III) and eliminate false results from other control ions by dual-mode.A novel sulfate-loaded iron-nitrogen co-doped carbon quantum dots (SO42--CQDs)-based fluorescent method was synthesized by the facile and environmentally friendly pyrolysis of persimmon frost (carbon source) and (NH4)2Fe(SO4)2·6H2O. After SMMC-7721 cells were incubated with the SO42--CQDs for 24 h, more than 95% of the cells remained viable, even at a high concentration of the SO42--CQDs, indicating excellent biocompatibility and low toxicity. In addition, it was able to be taken up by the cells to emit their bright blue fluorescence after excitation at 365 nm, indicating suitable cell permeability. The SO42--CQDs also exhibited a unique response to changes in pH, which was applied in the detection of OPs by relying on the production of acetic acid from the hydrolysis of acetylcholine (ACh) by acetylcholinesterase (AChE), which decreased the pH and engendered an increase in the fluorescence of the SO42--CQDs; however, the inhibition of AChE by glyphosate resulted in little influence on fluorescence intensity due to the lack of acetic acid produced. This mechanism was the basis for the development of a sensitive assay for the detection of glyphosate. The resulting assay had a limit of detection of 0.066 ng/mL. Furthermore, the method was successfully applied for the precise and accurate monitoring of the concentration, distribution, and variation of glyphosate residues in chives and cultivated soil. Therefore, the proposed method was anticipated to provide a promising alternative for other detection methods to enable the reliable analysis of OPs in food products.Molecularly imprinted polymers (MIPs) as artificial receptors have been widely applied in various fields. However, construction of MIPs for precise recognition of glycoprotein still remains a rather challenging task. To overcome this problem, we first fabricated boronate-affinity-oriented and sequential-surface imprinting magnetic nanoparticles (BSIMN) through integrating the boronate-affinity-oriented and sequential surface imprinting. The boronate-affinity-oriented immobilization of glycoprotein template endowed the BSIMN with homogeneous imprinted cavities. In addition, the polydopamine (PDA) imprinted layer was introduced by self-polymerization of dopamine in the first imprinting process, and then the phenylboronic acid (PBA) imprinted layer was introduced by boronate-affinity interaction in the second imprinting process. Surprisingly, the PBA imprinted layer possessed self-healing property due to the presence of pH-dependent boronate-affinity interaction between two imprinted layers. Therefore, the fabricated BSIMN exhibited excellent selectivity toward glycoprotein templates. To quantitatively detect glycoproteins in biological samples, the BSIMN was linked with hydrophilic rhodamine B-loaded/boronic acid-modified graphene oxide (HRBGO), which could selectively label glycoprotein and output amplified signal. In quantitative analysis, target glycoproteins were firstly captured by BSIMN and then specifically labeled by HRBGO; subsequently, the releasing agent was added to release numerous rhodamine B from HRBGO, and the corresponding fluorescence signal was used for further quantitative analysis. The proposed strategy showed ultrahigh sensitivity for ovalbumin, carcinoembryonic antigen and alpha fetoprotein with limit of detection of 4.5 fg mL-1, 3.6 fg mL-1 and 4.2 fg mL-1, respectively, and was successfully applied in determination of these glycoproteins in serum samples.G-quadruplex (G4)-hemin complexes are a convenient peroxidase mimicking DNAzyme for utilization in biosensing and analytical applications. Although dispersive G4/hemin DNAzymes have been extensively studied, a thorough investigation of the catalytic mechanism of multivalent G4/hemin (MultiG4) DNAzymes is warranted. To address this, dispersive G4/hemin DNAzymes with high-efficiency are connected by double- or multi-stranded DNA structures to build MultiG4 DNAzymes. The distance and environment of hemin binding sites are regulated by altering the position and spatial orientation of these connected G4s. Our data demonstrate that the catalytic activities of duplex-spaced MultiG4 DNAzymes are not affected by duplex length (within a reasonable range). However, vicinal MultiG4 DNAzymes that are immobilized at small spatial distances by Watson-Crick based DNA structures usually exhibit much lower catalytic activities than dispersive G4/hemin DNAzymes. Our results reveal that increasing the spatial flexibility of vicinal MultiG4 DNAzymes is imperative to achieving high catalytic efficiency. Significantly, we demonstrate that the catalytic activities of vicinal MultiG4 DNAzymes regulated by parallel duplexes are similar to that of dispersive G4/hemin DNAzymes, and that their activities are independent of the proximity effect. Thus, vicinal MultiG4 DNAzymes arranged in the same direction are more conducive to the maintenance of catalytic efficiency than those arranged in opposite directions. Our study provides a perspective for exploring multienzyme catalysis and should contribute to the design of nanozymes with high-efficiency catalytic activities.Fluorescence lifetime imaging microscopy (FLIM) is only related to the molecular structure and energy level distribution of the probe, not to the fluorescence intensity. It is an efficient imaging method, because it is not susceptible to interference from the internal environment of biological samples. Diabetes, as a systemic metabolic disease, causes various degrees of inflammation in organs and tissues. As we all know, inflammation of organ and tissue will affect cellular viscosity increases. In this work, a new amphiphilic molecular probe YF-V with a stable structure, good selectivity, fluorescence lifetime response and low cytotoxicity was designed. Under the condition of high viscosity, the rotation of the rotor and the twisting intramolecular charge transfer (TICT) mechanism were inhibited, leading to the extension of the fluorescence lifetime. In the cellular level, YF-V could sensitively detect the dynamic viscosity changes of cells induced by glucose through FLIM. Meanwhile, YF-V is also successfully applied to observe the difference in viscosity between the tissues and organs of diabetic mice and normal mice, and take lead in the detection of organ damage in diabetic mice with different disease durations. This provides an efficient and intuitive method for evaluating organ damage and early diagnosis in diabetes.Golgi protein 73 (GP73) is a new type of marker that can specifically detect hepatocellular carcinoma (HCC). Herein, a dual-signal sandwich-type electrochemical aptasensor for GP73 determination was constructed on the basis of hemin-reduced graphene oxide-manganese oxide (H-rGO-Mn3O4) nanozymes. Gold@poly(o-phenylenediamine) (Au@POPD) nanohybrids with a large specific surface area and conductance were co-electro-deposited onto a screen-printed electrode (SPE) surface to immobilize GP73 capture aptamer 2 (Apt2). H-rGO-Mn3O4 nanozymes were used not only to immobilize amino functionalised GP73 aptamer 1 (Apt1) as the detection probe, but also to serve as an in-situ redox signal indicator because of the redox reaction of Hemin (Fe(Ш)/Hemin(Fe(II)). In addition, given their excellent peroxidase-like activity, H-rGO-Mn3O4 nanozymes can catalyse the decomposition of H2O2 and oxidation of substrate (3,3',5,5'-tetramethylbenzidine, TMB) to oxTMB, which is used as another redox signal. In the presence of the target GP73, the two aptamers specifically bind to the target, thereby affecting two electrochemical signals. Under optimal conditions, the dual-signal sandwich-type electrochemical aptasensor had a salient analytical performance. The two electrochemical redox signals linearly increase with the logarithm of the GP73 concentration in the range of 0.01-100.0 ng/mL with the limit of detection (LOD) of 0.0071 ng/mL and sensitivity of 2.441 μA/μM/cm2. Moreover, the recovery of human serum samples ranged from 98.66% to 121.11%. Furthermore, the two redox signals can simultaneously corroborate each other, thereby preventing missed diagnosis and misdiagnosis. All the results can provide new insights into the clinically effective determination of HCC.With the aid of good biocompatibility and stability with hydroxyapatite (HAp) in protein separation and adsorption fields, we developed a novel extraction-isolation albumin analysis method by relying on the specific adsorption capacity of HAp, combining with surface-enhanced Raman spectroscopy (SERS) for prostate cancer screening. Two different nanostructures of HAp particles, including the HAp flower and HAp sphere, were synthesized with a hydrothermal method, and the targeted binding and extraction abilities of serum albumin of these two HAp particles were compared. By changing the morphology of the nanostructure, the albumin-adsorption capacity of HAp varied significantly. Compared with spherical HAp particles, HAp flower particles have more albumin binding sites per unit area. Thus, the HAp flower displayed the superior capacity for adsorption-release of albumin, which was further employed for clinical prostate cancer screening. Based on the superior adsorption-extraction ability of albumin of HAp flower, serum albumin was adsorbed and extracted by HAp flower from serum samples of prostate cancer patients (n = 30) and healthy volunteers (n = 30), and mixed with silver colloids to perform SERS spectral analysis. The partial least square-support vector machines (PLS-SVM) model is used to analyze the obtained serum albumin SERS spectra and establish the diagnostic model, the diagnostic accuracy was up to 95.00% for differentiating the normal volunteer from prostate patient groups. The results demonstrate that the PLS-SVM model provides superior performance in the classification of a prostate cancer diagnosis. Due to the advantages of simplicity and rapidness, the HAp flower-adsorbed-released albumin combined with SERS was expected to become a promising tool for prostate cancer detection.Glutathione (GSH) plays important roles in various physiological processes, thus highly sensitive assay of GSH and timely warning of its variation at trace level in complex biological matrixes is of great significance. However, this is challenging due to the coexisting reductive biomolecules and dynamic change of GSH levels in responding to various stimuli which remain largely unexploited. Herein, we report a dual mode protocol for the assay of GSH based on nanoconjugate g-C3N4Tb/MnO2 between MnO2 nanosheets and terbium-doped g-C3N4 (g-C3N4Tb) nanosheets. MnO2 moiety effectively quenches the emission at 546 nm from Tb3+ in the nanoconjugate, which is restored under the reduction of MnO2 by GSH to ensure fluorescence turn-on assay of GSH. Meanwhile, the generated Mn2+ facilitates inductively coupled plasma mass spectrometry (ICP-MS) detection to endow indirect highly sensitive assay of GSH. Fluorescence mode derived a limit of detection (LOD) of 0.17 μmol L-1 within a linear range of 0.5-160 μmol L-1, while ICP-MS resulted in a superior LOD of 0.