Frombroberg0712

The strategy exhibited the limit of detection as low as 0.009 U mL-1 and 0.003 U mL-1 for Dnmt1 and UDG, respectively. Meanwhile, this strategy was successfully applied to detect Dnmt1 and UDG activities in living cell samples at single-cell level and assay the inhibitors of Dnmt1 and UDG. Therefore, the strategy provided a potential method to detect Dnmt1 and UDG activities in biological samples for early clinic diagnosis and therapeutics. Gasotransmitter hydrogen sulfide (H2S), produced enzymatically in body, has important functions in biological signaling and metabolic processes. RHO-15 An abnormal level of H2S expression is associated with different diseases, therefore, development of novel bioanalytical methods for rapid and effective detection of H2S in biological conditions is of great importance. In this work, we report the development of a new responsive nanosensor for ratiometric luminescence detection of H2S in aqueous solution and live cells. The nanosensor (Ru@FITC-MSN) was prepared by immobilizing a luminescent ruthenium(II) (Ru(II)) complex into a fluorescein isothiocyanate (FITC) conjugated water-dispersible mesoporous silica nanoparticle (MSN), showing dual emission bands at 520 nm (FITC) and 600 nm (Ru complex). The red luminescence of the formed Ru@FITC-MSN was quenched in the presence of Cu2+. The in-situ generated Ru-Cu@FITC-MSN responded to H2S rapidly and selectively, showing a linear ratiometric luminescence change in FITC and Ru(II) channels with the H2S concentration (0.5-4 μM). Limit of detection (LoD) and limit of quantification (LoQ) were determined to be 0.36 and 1.21 μM. Followed by investigation of cellular uptake processes, the utility of the nanosensor for ratiometric imaging of H2S in live cells and its capability to monitor H2S levels in inflammatory breast cancer cells were then demonstrated. This study provides a powerful approach for detection of highly reactive and unstable H2S biomolecules in live systems. Model-based algorithms have recently attracted much attention for data pre-processing in tissue mapping and imaging by Fourier transform infrared micro-spectroscopy (FTIR). Their versatility, robustness and computational performance enabled the improvement of spectral quality by mitigating the impact of scattering and fringing in FTIR spectra of chemically homogeneous biological systems. However, to date, no comprehensive algorithm has been optimized and automated for large-area FTIR imaging of histologically complex tissue samples. Herein, for the first time, we propose a unique, integrated and fully-automated Multiple Linear Regression Multi-Reference (MLR-MR) method for correcting linear baseline effects due to diffuse scattering, for compensating substrate thickness inhomogeneity and accounting for sample chemical heterogeneity in FTIR images. In particular, the algorithm uses multiple-reference spectra for histologically heterogeneous biological samples. The performance of the procedure was demonstrated for FTIR imaging of chemically complex rat brain frontal cortex tissue samples, mounted onto Ultralene® films. The proposed MLR-MR correction algorithm allows the efficient retrieval of "pure" absorbance spectra and greatly improves the histological fidelity of FTIR imaging data, as compared with the one-reference approach. In addition, the MLR-MR algorithm here presented opens up the possibility for extracting information on substrate thickness variability, thus enabling the indirect evaluation of its topography. As a whole, the MLR-MR procedure can be easily extended to more complex systems for which Mie scattering effects must also be eliminated. In this work, we developed a naked-eye colorimetric and ratiometric fluorescence probe for a very important biomarker of uric acid (UA). The method was based on the oxidation of UA by uricase to allantoin and hydrogen peroxide, and then o-Phenylenediamine (OPD) was oxidized to the yellow-colored 2,3-diaminophenazine (oxOPD) in the presence of horseradish peroxidase (HRP) and hydrogen peroxide. The fluorescence emission of glutathione functionalized Ti3C2 MQDs (GSH-Ti3C2 MQDs) centered at 430 nm overlaps with the UV absorption of oxOPD at 425 nm to a large extent, which facilitates fluorescence resonance energy transfer (FRET) between GSH-Ti3C2 MQDs and oxOPD. With the increase of the UA concentration, the emission at 430 nm of GSH-Ti3C2 MQDs is progressively quenched and the emission at 568 nm of oxOPD was gradually increased. Moreover, the probe we designed is easier to distinguish with color change by naked eye for the detection of UA. This is the first report about the determination of UA by a naked-eye colorimetric and ratiometric fluorescence method combining GSH-Ti3C2 MQDs and uricase/HRP enzymes. This work enables assays to perform fluorescence and visual detection of biomarker in biological fluids based on Ti3C2 MQDs. V.Isoflavones are the major bioactive components in soybeans. Sequential window acquisition of all theoretical fragment ions (SWATH) is a kind of data-independent acquisition (DIA), such that all fragments of each precursor will be preserved in a SWATH-Mass Spectrometry (SWATH-MS) run. In this study, a high-throughput SWATH-MS method for the determination of 12 isoflavones in soybeans was established. Furthermore, amino acids, saponins can be semi-quantitated from the same SWATH-MS data. Combination of targeted quantification and untargeted profiling with SWATH, all bioactive compounds were analyzed within 5 min in 10 min run time, and the method had good linear regression with r2 > 0.99. The precisions (RSD %) of the intra-day and inter-day analyses ranged from 2.11% to 18.7%, and the accuracies (RE%) ranged from -14.39% to 17.48%. The matrix effect ranged from 88.66% to 114.82%. Moreover, 7 varieties of soybeans were analyzed and compared with this robust screening method. This work presents a novel development that exploits the concept of in-situ gas-separation together with a specific enzymatic colorimetric detection to produce a portable biosensor called "Blood Alcohol Micro-pad" for direct quantitation of ethanol in whole blood. The thin square device (25 mm × 25 mm × 1.8 mm) comprises two layers of patterned filter paper held together with a double-sided mounting tape with an 8-mm circular hole (the headspace). In operation, the reagent is deposited on one layer and covered with sticky tape. Then 8 μL of a blood sample is dispensed onto the opposite layer and covered with sticky tape. Diffusion of ethanol across the 1.6 mm narrow headspace permits selective detection of ethanol by the enzymatic reagents deposited on the opposite layer. This reagent zone contains alcohol oxidase, horseradish peroxidase and 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, as the chromogenic reagent. The color intensity, measured from the recorded digital image, resulting from the enzymatic assay of ethanol, correlates with the concentration of blood alcohol.