ABSTRACT
Uric acid (UA) is a metabolic byproduct of purine nucleotides and is excreted as a urine component. Abnormalities in UA metabolism cause localized inflammation due to crystal deposition and can lead to various diseases. In the current study, we successfully fabricated a biosensor based on 1-H-3-methylimidazolium acetate (ionic liquid, IL)-capped nickel nanoparticles (NiNPs) for the detection of uric acid in test samples. The structures of IL-capped NiNPs and their precursors were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The IL-capped NiNPs possessed intrinsic peroxidase-like properties and displayed selective UA quenching after interacting with 3,3',5,5'-tetramethylbenzidine (TMB) solution. Different parameters such as pH, time, IL, TMB, and UA concentration were optimized to obtain the best results for the proposed sensor. The UA biosensor shows good responses in the linear range from 1 × 10-8 to 2.40 × 10-6 M, with a lower limit of detection of 1.30 × 10-7 M, a limit of quantification of 4.3 × 10-7 M, and an R 2 value of 0.9994. For the colorimetric detection of UA, the proposed sensor gave a short time response of 4 min at room temperature and pH 7.5. The proposed sensing probe detects UA in real serum samples and could be used as a selective sensor for UA in the real sample detection.
ABSTRACT
The current study reports advanced, ecofriendly and biosynthesized silver NPs for diverse biomedical and environmental applications using Flammulina velutipes as biosource. In the study, a simple aqueous extract of F. velutipes was utilized to reduce the AgNO3 into stable elemental silver (Ag0) at a nanometric scale. The NPs had average size of 21.4 nm, spherical morphology, and were highly stable and pure. The characterized nanoparticles were exploited for a broad range of biomedical applications including bacteriocidal, fungicidal, leishmanicidal, in vitro antialzheimer's, antioxidant, anti-diabetic and biocompatibility studies. Our findings showed that F. velutipes mediated AgNPs exhibited high activity against MDR bacterial strains and spore forming fungal strains. All the tested urinary tract infection bacterial isolates, were resistant to non-coated antibiotics but by applying 1% of the synthesized AgNPs, the bactericidal potential of the tested antibiotics enhanced manifolds. The NPs also exhibited dose-dependent cytotoxic potential against Leishmania tropica with significant LC50 of 248 µg ml-1 for promastigote and 251 µg ml-1 for amastigote forms of the parasite. Furthermore, promising antialzheimer and antidiabetic activities were observed as significant inhibition of α-amylase, α-glucosidase, acetylcholinesterase (AChE) and butrylcholineterase (BChE) were noted. Moreover, remarkable biocompatible nature of the particles was found against human red blood cells. The biosynthesized AgNPs as photocatalyst, also resulted in 98.2% degradation of indigo carmine dye within 140 min. Owing to ecofriendly synthesis, biosafe nature and excellent physicochemical properties F. velutipes AgNPs can be exploited as novel candidates for multifaceted biomedical and environmental applications.
Subject(s)
Anti-Infective Agents/pharmacology , Flammulina , Metal Nanoparticles/chemistry , Silver/chemistry , Silver/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/chemistry , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Dose-Response Relationship, Drug , Dynamic Light Scattering , Flammulina/chemistry , Flammulina/metabolism , Humans , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Leishmania tropica/drug effects , Metal Nanoparticles/administration & dosage , Microbial Sensitivity Tests , Microscopy, Electron, Scanning , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Silver/administration & dosage , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , ThermogravimetryABSTRACT
The formulation of optoelectronic components into 1D nanostructures allows the promotion of new materials with multifunctionalities. In this work, it is demonstrated that new synthesis of photocatalytic carbon nanofiber decorated with semi-embedded titanium oxide (TiO2 ), namely, TiO2 @carbon fiber, is conveniently accessed through the electrospinning of polyacrylonitrile polymer and TiO2 particle comixture, and then followed by photon-activated self-erosion to expose the embedded TiO2 and carbonization. The hybrid nanofibers are characterized by field emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis. Furthermore, the photocatalytic activities of the resultant fibers are tested with photodegradation of Rhodamine B in aqueous solution, which reveals that the carbon nanofiber with semi-embedded TiO2 drastically improved catalytic efficiency and recyclability, comparing to those fibers without or with embedded TiO2 .
