- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Optical aptasensor based on silver nanoparticles for the colorimetric detection of adenosine
摘要： A new and straightforward optical sensor for the colorimetric determination of adenosine (AD) in human urine samples was developed. The sensor comprised silver nanoparticles (AgNPs) as colorimetric elements and anti-AD aptamer (AP) as a recognition probe. In a solution containing AD and high concentration of NaCl, due to the unique binding of AD with AP, the aggregated metal nanomaterials dispersed in the solution, and the color intensity of the solution was changed accordingly. The absorbance of the solution was monitored for AD quantification. The method was applicable for the determination of AD in the concentration range of 60–280 nM with the detection limit of 21 nM. The relative standard deviation ranged from 4.8 to 8.8% for six replicates. The method showed excellent selectivity toward AD checked over some probable interfering compounds. To investigate the performance of AgNPs, the analytical characteristics of the method including linear range, detection limit, selectivity, and precision were compared with those obtained by a common AuNPs-based aptasensor. The reliability of the method was further ascertained for the detection of AD in urine samples of two lung cancer patients with percentage recoveries in the range of 98–107%.
关键词： Adenosine,Silver nanomaterials,Colorimetric,UV–vis absorption spectroscopy,Aptamer
更新于2025-09-23 15:22:29
-
Single-step formation of Cr 2 N nanoparticles by pulsed laser irradiation
摘要： Chromium nitride nanoparticles with mean diameter distribution between 0.8 nm and 30 nm were produced by laser irradiation of a chromium target immersed in liquid nitrogen. Cr was directly converted to chromium nitride nanoparticles according to selected-area electron diffraction analyses using the transmission electron microscopy technique. Crystalline nanoparticles mostly consist of Cr2N, which is commonly reported together with the conversion of Cr2N to CrN and the mixture of chromium oxides. In addition, there is no evidence of oxidation by storage or photodegradation of the nanoparticles in isopropyl alcohol suspensions. The intensity profile of small-angle X-ray scattering indicates that the geometrical shape of the nanoparticles is not spherical but cylindrical with aspect ratio (height-to-radius) of 0:35–0:05. UV-Vis absorption spectroscopy reveals the presence of surface plasmon absorption at the ultraviolet region at wavelengths of 350, 372, and 397 nm. First-principles calculations of density of states, dielectric function, and optical conductivity performed within the theoretical framework of density functional theory for Cr2N with a hexagonal structure corroborate the formation of surface plasmons.
关键词： transmission electron microscopy,liquid nitrogen,chromium nitride nanoparticles,density functional theory,laser irradiation,UV-Vis absorption spectroscopy
更新于2025-09-11 14:15:04