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Powerful and Collision-Free Creation Control of Multiagent Methods Together with Constrained Information.
Thus, the visual assay achieved sensitive detection of telomerase activity, and the limit of detection (LOD) reached as low as 10 HeLa cells/μL by naked eyes and 4.5 HeLa cells/μL by absorbance measurements. Therefore, it offers a sensitive and low-cost method for visual detection of telomerase activity, which also, widens the application of commercial hydrogen peroxide test strip in the development of non-H2O2 biosensors. Quantitative analysis is critical for biological and chemical sensing applications, yet still remains a great challenge in surface-enhanced Raman spectroscopy (SERS). Here we report the development of a novel fractal SERS nanoprobe with robust internal calibration standard and high multiplexing capability for ultrasensitive detection of DNA and microRNA. This fractal SERS nanoprobe consists of a solid Au core of ~13 nm, an inner hollow gap of ~1 nm, and a stellate outer shell. The inner hollow gap enables the embedding of Raman tags that can serve as a self-calibrating internal standard to effectively correct the fluctuations of samples and measuring conditions. The outer shell morphology is highly tunable, which provides distinct SERS enhancement and enables a reproducible quantitative measurement of nucleic acids down to femtomolar level. In addition, the flexibility of encoding crosstalk-free Raman tag molecules makes such SERS sensor particularly attractive for multiplexed bioassays. This technique is simple, reliable, and of wide applicability to various genomic screening and diagnostic applications. Field effect transistor (FET) biosensors based on low-dimensional materials have the advantages of small in size, simple structure, fast response and high sensitivity. In this work, a field-effect transistor biosensor based on molybdenum disulfide/graphene (MoS2/graphene) hybrid nanostructure was proposed and fabricated for DNA hybridization detection. The biosensor achieved an effective response to DNA concentrations in a broad range from 10 aM to 100 pM and a limit of detection (LOD) of 10 aM was obtained, which was one or more orders of magnitude lower than the reported result. The sensing mechanisms (donor and gating effects) of the FET sensor were discussed. A larger voltage shift of the charge neutral point was obtained due to a strengthened donor effect and a weakened gating effect caused by the introduction of MoS2 layers. Such FET sensor shows high specificity for different matching degrees of complementary DNA, indicating the potential use of such a sensor in disease diagnosis. selleck chemical Biophysical cues, such as electrical stimulus, mechanical feature, and surface topography, enable the control of neural stem cell (NSC) differentiation and neurite outgrowth. However, the effect of these biophysical cues on NSC behavior has not been fully elucidated. In the present study, we developed an innovative combinatorial biophysical cue sensor array combining a surface modified nanopillar array with conductive hydrogel micropatterns. The micro/nanopattern comprised silicon oxide-coated polyurethane nanopillar arrays on a flexible film and conductive hydrogel micropatterns including polyethylene glycol (PEG) hydrogel, silver nanowires (AgNW), and reduced graphene oxide (rGO). A computational fluid dynamic (CFD) model was used to optimize the design parameters of the nanopillar arrays. In the study, we successfully demonstrated that SiO2-coated nanopillar array enhanced the differentiation of NSCs and efficiently regulated neuronal behavior, such as neurite outgrowths, by conductive hydrogel micropatterns combined with electrical stimuli. Therefore, our innovative combinatorial biophysical cue sensor array to control NSC behavior via electrical stimuli can be potentially useful to study neurodegenerative and neurological disorder therapy applications. The majority of analytical chemistry methods requires presence of target molecules directly at a sensing surface. Diffusion of analyte from the bulk towards the sensing layer is random and might be extremely lengthy, especially in case of low concentration of molecules to be detected. Thus, even the most sensitive transducer and the most selective sensing layer are limited by the efficiency of deposition of molecules on sensing surfaces. However, rapid development of new sensing technologies is rarely accompanied by new protocols for analyte deposition. To bridge this gap, we propose a method for fast and efficient deposition of variety of molecules (e.g. proteins, dyes, drugs, biomarkers, amino acids) based on application of the alternating electric field. We show the dependence between frequency of the applied electric field, the intensity of the surface enhanced Raman spectroscopy (SERS) signal and the mobility of the studied analyte. Such correlation allows for a priori selection of parameters for any desired compound without additional optimization. Thanks to the application of the electric field, we improve SERS technique by decrease of time of deposition from 20 h to 5 min, and, at the same time, reduction of the required sample volume from 2 ml to 50 μl. Our method might be paired with number of analytical methods, as it allows for deposition of molecules on any conductive surface, or a conductive surface covered with dielectric layer. V.The rapid increase in antibiotic resistant pathogenic bacteria has become a global threat, which besides the development of new drugs, requires rapid, cheap, scalable, and accurate diagnostics. Label free biosensors relying on electrochemical, mechanical, and mass based detection of whole bacterial cells have attempted to meet these requirements. However, the trade-off between selectivity and sensitivity of such sensors remains a key challenge. In particular, point-of-care diagnostics that are able to reduce and/or prevent unneeded antibiotic prescriptions require highly specific probes with sensitive and accurate transducers that can be miniaturized and multiplexed, and that are easy to operate and cheap. Towards achieving this goal, we present a number of advances in the use of graphene field effect transistors (G-FET) including the first use of peptide probes to electrically detect antibiotic resistant bacteria in a highly specific manner. In addition, we dramatically reduce the needed concentration for detection by employing dielectrophoresis for the first time in a G-FET, allowing us to monitor changes in the Dirac point due to individual bacterial cells.
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