- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Label-free detection of folic acid using a sensitive fluorescent probe based on ovalbumin stabilized copper nanoclusters
摘要： In this work, ovalbumin (OVA) stabilized copper nanoclusters (OVA-Cu NCs) were prepared through a simple protein-stabilized synthetic method and applied for the sensitive determination of FA. Cu2+ ions were directly reduced to Cu (0) by a mild reducing agent, N2H4·H2O, at room temperature without any other complicated procedure such as adjusting pH and controlling the temperature of the reaction mixture. The as-prepared OVA-Cu NCs showed good chemical stability, wonderful water solubility and excellent biocompatibility. The OVA-Cu NCs were obtained with an average particle size of 2.0 nm and good dispersibility in aqueous solution. They also showed strong red emitting at 625 nm with a quantum yield of 3.95%. The OVA-Cu NCs were then applied for label-free detection of FA based on a static quenching mechanism. The linear calibration curve of detecting FA served from 0.5 μM -200 μM with the detection limit of 0.18 μM. In addition, the developed method was also successfully applied to determine the content of FA in tablet, spinach, orange juice and biological samples with quantitative spike recoveries from 96.9% to 100.9%. For these reasons, the developed OVA-Cu NCs-based fluorescent strategy can thus offer a convenient label-free biosensor platform for the detection of FA in biomedical applications.
关键词： label-free detection,folic acid,red emitting,copper nanoclusters
更新于2025-09-09 09:28:46
-
Association between seasonal serum folate levels and ultraviolet radiation
摘要： UV radiation has been consistently reported to cause folate photodegradation in vitro and in human skin. Seasonal variations in UV radiation might explain seasonal changes in folate levels in blood. Yet, few studies have addressed this phenomenon. The main objective of this study was to investigate whether a relationship exists between seasonal variations in serum folate levels in a population of Spain (Latitude: 36° 41' 6.88''; Longitude: 4° 30' 0.64'') and the annual variations of solar ultraviolet reached in the localization. From a sample of 118831 serum folate determinations, two studies were performed. The first one, which included all subjects, showed a decreased in mean folate concentrations in all seasons with respect to winter with lower values in summer. The risk of folate deficiency was 1.37 times greater in summer than in winter (95%CI: 1.29-1.46). In the second study, subjects with a first folate determination in winter and a second one in summer were 3.32 more likely to develop folate deficiency than those with a first folate determination in summer and a second one in winter (95%CI: 1.55 to 7.11). Folate levels showed a seasonal variation inversely related to solar total UV radiation reached in our location, with maximum daily doses of 5000 J m-2 reached in June. A gradual increase in percentage of folate deficiency is observed since spring. So, patients with folate levels close to deficiency are at a higher risk of having folate deficiency in summer.
关键词： folic acid,solar ultraviolet radiation,seasonal variation,folate deficiency,folate,photodegradation,population study
更新于2025-09-09 09:28:46
-
Folic acid-nanoscale gadolinium-porphyrin metal-organic frameworks: fluorescence and magnetic resonance dual-modality imaging and photodynamic therapy in hepatocellular carcinoma
摘要： Background: Hepatocellular carcinoma (HCC) is the most common primary liver cancer and severely threatens human health. Since the prognosis of advanced HCC remains poor, there is an urgent need to develop new therapeutic approaches. Porphyrin metal-organic frameworks are a class of porous organic-inorganic hybrid functional materials with good biocompatibility. Methods: Gadolinium-porphyrin metal-organic frameworks were used as a skeleton for folic acid (FA) conjugation to synthesize a novel type of nanoparticle, denoted as folic acid-nanoscale gadolinium-porphyrin metal-organic frameworks (FA-NPMOFs). The FA-NPMOFs were characterized using transmission electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric-differential thermal analysis. The biotoxicity and imaging capability of the FA-NPMOFs were determined using HepG2 cells and embryonic and larval zebrafish. The delivery and photodynamic therapeutic effect of FA-NPMOFs were explored in transgenic zebrafish with doxycycline-induced HCC. Results: FA-NPMOFs were spherical in structure with good dispersion and water solubility. They showed low biotoxicity, emitted bright red fluorescence, and exhibited an excellent magnetic resonance imaging capability, both in vitro and in vivo. Meanwhile, the FA-NPMOFs exhibited a strong affinity for folate receptor (FR)-expressing cells and were delivered to the tumor site in a targeted manner. Moreover, HCC tumor cells were eliminated following laser irradiation. Conclusion: FA-NPMOFs can be used for dual-modality imaging and photodynamic therapy in HCC and show promise for use as a carrier in new therapies for HCC and other FR-positive tumors.
关键词： nanoscale gadolinium-porphyrin metal-organic frameworks,folic acid,hepatocellular carcinoma,photodynamic therapy,dual-modality imaging
更新于2025-09-04 15:30:14