Ashby Sander (risehorn8)

Thus, by measuring the system fluorescence intensity and exploiting FRET signal difference, UDG activity can be detected in a simple process. The detection limit is 0.087 U/mL without requiring additional signal amplification process. Besides, our developed strategy can also be used for screening the UDG inhibitors in a ratiometric fluorescence detection way.A novel approach for the online coupling of solid-phase microextraction (SPME) and liquid chromatography (LC) is introduced. An innovative Si@GO@βCD coated needle-sleeve extractant device was developed and then employed in the automated online SPME-LC-UV determination of estrogen-like isoflavones from human urine samples. The extractant SPME device is easily attachable at the endpoint of an analytical syringe needle and operated by a lab-made autosampler. Fully automated online SPME-LC is accomplished by proper autosampler programming to perform the following steps i) the analytes extraction by direct immersion of the extractant device into the stirred sample, ii) a rinsing step iii) the analytes desorption/enrichment, iv) the online transference of the extract to the LC injection valve. Besides allowing the online SPME hyphenation, this extraction modality efficiently addressed the drawbacks associated with the clogging and dispersion of graphene-based microextraction techniques performed in packed-bed and dispersive formats. The main extraction parameters and the performance of the automated online SPME-LC method developed were carefully studied. The results show a good sensitivity, reliability, and straightforward analytical strategy for the determination of organic compounds in complex samples. The detection limit of the method was 20 μg L1 for DAI and 10 μg L-1 for GEN, FOR and BIO. The intra-day RSD was below 10% and inter-day RSD was below 13%. The total analysis time was less than 17 min per sample.Drug-induced liver injury (DILI) has been a hot issue of public health, owing to its unpredictability and serious harm to public health. Peroxynitrite (ONOO-) is an important biomarker for the assessment and diagnosis of DILI. In this article, based on a kind of rhodamine analogue with a near-infrared (NIR) emission (610 nm-800 nm) and a two-photon absorption cross section (54 GM), a two-photon excited NIR fluorescence probe (NIR-ONOO) for ONOO- was developed. With a high selectivity and a high sensitivity to ONOO-, NIR-ONOO has a linear range for detection of ONOO- from 5.0 × 10-8 to 1.0 × 10-5 M, a good detection limit (15 nM) and a large fluorescence enhancement (340-fold). In addition, NIR-ONOO has been used to monitor ONOO- in cells with satisfactory results. Because of its two-photon excied NIR emission, NIR-ONOO also showed excellent performances for imaging ONOO- including low autofluorescence, stable and persistent fluorescence, and a deep penetration (204 μm). Finally, NIR-ONOO was successfully employed to image ONOO- in inflammatory mouse, drug-induced hepatotoxicity in cells and its remediation. All the results indicated that NIR-ONOO is a powerful chemical tool to image ONOO- and assay drug-induced hepatotoxicity.Due to favourable efficiency and low cost, dual-response fluorescent probes play critical roles in the development of fluorescence assay system. Herein, a novel dual-response fluorescent probe (RDCN) was designed and synthesized for the detection of two environmental contaminants hydrazine (N2H4) and cyanide (CN-). Probe RDCN exhibited discriminative sensing behaviors to N2H4 and CN- with different reaction mechanisms, allowing the high selectivity and sensitivity detection for N2H4 and CN-. The probe itself displayed red-emitting fluorescence as a result of strong intramolecular charge transfer (ICT) between diethylamino and dicyano. After mixing with hydrazine, a new corresponding hydrazone came into being with an intense yellow fluorescence. While, the probe could also largely switch to blue fluorescence in response to CN-. Glycochenodeoxychol