Brixmathis6046

This new SSRE-fiber platform paves a way for the design of highly stretchable and stable electrochemical sensor capable of integrating into textiles for wearable biochemical detection applications. A new and easy to construct sheathless capillary electrophoresis electro spray ionization mass spectrometry (CE-ESI-MS) interface was developed that offers several advantages compared to traditional liquid junction interfaces. The fabrication of the device only requires a CO2 laser engraver that most groups working with microfluids have access to. It only takes a few seconds to create a CO2 laser ablated opening in the bare-fused silica capillaries and the opening can be placed as close as a few mm from the spray tip. The capillary is punctured through a silicone tube such that the opening is directly placed inside this tube, which also serves as a liquid reservoir for the make-up liquid. Electrical contact required for both CE separation and ESI is established via the liquid in this reservoir which is in contact with the electrode of an external high voltage power supply. The developed CE-ESI-MS interface is capable of analysing both small molecules and biomolecules such as peptides in physisorbed PEG polymer brush coated capillaries. Proof-of-principle of the interface was demonstrated by analysing a tryptic digest of BSA. Further, a range of drugs of abuse were also investigated. The examined small molecules (pethidine, nortriptyline, methadone, haloperidol and loperamide) have a quantification limit (LOQ) of 150 ng/mL and a detection limit (LOD) of 40 ng/mL (except for loperamide LOD = 80 ng/mL). Finally, we used our novel CE-MS interface for the analysis of the Aβ40 peptide. This is a member of the beta-Amyloid peptide family, involved in the development of Alzheimer's disease. A LOQ of 9 μg/mL was obtained for Aβ40, corresponding to 23 fmoles in a sample volume of 11 nL. The biosensors based on aptamer based stimuli-responsive hydrogels have the characters of high specificity, good stability, portability. Electronic balance is one of the most accurate equipment and can be reached nearly in all labs. Aflatoxin B1 (AFB1) is highly toxic and carcinogenic to humans and animals, it is necessary to develop simple and convenient detection method to apply in resource limited area. In this study, a novel strategy for quantitative detection of AFB1 has been developed by combining the high selectivity and convenient of target-responsive hydrogel and the simple of using electronic balance as readout devices. The AFB1 target responsive double crosslinked hydrogel has been constructed using linear hyaluronic acid grafted single-stranded DNA complex as the backbone, AFB1 aptamer and polyethyleneimine as crosslinkers. And platinum nanoparticles (PtNPs) had been embedded in the hydrogel firstly. The present of AFB1 can bind with the aptamer with high affinity and cause the releasing of aptamer from hydrogel. The addition of Exo I can specifically recognize and cleave the aptamer in AFB1-aptamer complex, resulting in the releasing of AFB1, which can react with the hydrogel again, thereby achieving the target cycle. By this means, the hydrogel will collapse and many pre-embedded PtNPs can be released. The transferring of the released PtNPs to a drainage device which contains H2O2 can results in the increasing of the internal pressure since the production of oxygen through the catalytic decomposition of H2O2 by PtNPs has low solubility. Selleckchem EGFR inhibitor Which will cause the discharging of water from the system and this can be collected and weighed by an electronic balance easily. The weight of water has a linear relationship with AFB1 concentration. Under 30 min catalytic time, the linear range is 31.2 μg/kg - 6.2 mg/kg with the detection limit of 9.4 μg/kg (S/N = 3). The proposed method was successfully applied to the detection of AFB1 in peanut samples. C-reactive protein (CRP) is a clinical biomarker for inflammatory diseases. In this work, we present a simple and fast colorimetric method for CRP detection that employs citrate-capped gold nanoparticles (AuNPs) and a CRP-binding aptamer as sensing elements. The aptamer consisted in a guanine rich single-stranded DNA (ssDNA) that adsorbs onto the surface of the AuNPs. In the presence of the CRP, the ssDNA releases from the AuNPs surface to interact preferentially with the protein to form guanine-quadruplexes. The exposure of the unprotected AuNPs to buffer salts leads to aggregation and subsequent color change from red-wine to blue-purple that was readily seen by the naked eye. The AuNPs aggregation was monitored using UV-Vis spectroscopy and the CRP concentration in the samples could be correlated with the aggregation ratio (A670nm/A520nm). A linear sensing range of 0.889-20.7 μg/mL was found. The detection limit (LOD) was 1.2 μg/mL which is comparable to the typical clinical cutoff concentration in high-sensitivity CRP assays (1 μg/mL) and lower than the detection limit of nephelometric methods used in clinical practice. This method can provide a fast (5 min analysis time), simple, and sensitive way for CRP detection, with negligible interference of bovine serum albumin (BSA) up to concentrations of 100 nM. A procedure for separation and preconcentration of tetracyclines from human serum samples involving magnetic dispersive micro-solid phase extraction was proposed. The extraction efficiency of different tetracyclines was improved with the use of the surfactant coated Fe3O4 magnetic nanoparticles. Sorption mechanism was presented, and the potential use of magnetic Fe3O4 nanoparticles coated with different surfactants for tetracyclines adsorption was demonstrated for the first time. The procedure involved nanoparticle floating in a liquid sample phase for analyte extraction followed by elution and determination by high performance liquid chromatography with diode array detection. Influence of the main involved parameters was studied, the system was dimensioned accordingly. The analytical curves were linear in the ranges of 0.25-10 mg L-1 for tetracycline and 0.10-10 mg L-1 for oxytetracycline or doxycycline. Limits of detection were estimated (IUPAC, 3 concept) as 0.08 mg L-1 for tetracycline, and 0.03 mg L-1 for oxytetracycline or doxycycline.