A graphene sample (EGr) was prepared by electrochemical exfoliation of graphite rods in solution containing 0.05 M (NH)SO + 0.1 M HBO + 0.05 M NaCl. The exfoliation was performed by applying a constant voltage (12 V) between the graphite rods, while the temperature was kept constant (18 °C) with a temperature-controlled cryostat. The structural investigation of the graphene sample, performed by X-ray powder diffraction (XRD), revealed that the sample consists of a mixture of few-layer (69%), multi-layer graphene (14%) and graphene oxide (17%). In addition, XPS analysis proved that the sample was triple-doped with heteroatoms such as nitrogen (1.7 at%), sulfur (2.5 at%), and boron (3 at%). The sample was deposited onto the surface of a clean, glassy carbon electrode (GC) and investigated for the non-enzymatic electrochemical detection of L-tryptophan (TRP). The electrocatalytic properties of the EGr/GC electrode led to a considerable decrease in the oxidation potential from +0.9 V (bare GC) to +0.72 V. In addition, the EGr/GC electrode has higher sensitivity (two times) and a lower detection limit (ten times) in comparison with the bare GC electrode.
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http://dx.doi.org/10.3390/bios11020036 | DOI Listing |
Nanoscale
January 2025
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
Current molecular tests for tuberculosis (TB), such as whole genome sequencing and Xpert /rifampicin resistance assay, exhibit limited sensitivity and necessitate the pre-amplification step of target DNA. This limitation greatly increases detection time and poses an increased risk of infection. Here, we present a graphene field-effect transistor (GFET) based on the CRISPR/Cas system for detecting .
View Article and Find Full Text PDFLangmuir
January 2025
College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P.R. China.
Morphology regulation and element doping are effective means to improving the photocatalytic performance of graphite-phase carbon nitride (g-CN). In this article, using melamine and zinc chloride as raw materials, a novel kind of Zn/Cl-doped hollow microtubular g-CN (Zn-HT-CN) by a hydrothermal method was developed. The structure and morphology of Zn-HT-CN and reference samples were characterized by X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), etc.
View Article and Find Full Text PDFTalanta
January 2025
School of Agricultural Engineering, Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, Jiangsu University, Zhenjiang, Jiangsu, 212013, China; College of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang, Henan, 471003, China. Electronic address:
Searching for new alternative to tripropylamine (TPrA) with low toxicity and high chemical stability for the tris(4,4'-dicarboxylic acid-2,2'-bipyridyl)ruthenium (II) (Ru(dcbpy)) based coreactant electrochemiluminescence (ECL) system is essential for widespread analytical applications. Here, nitrogen-doped graphene quantum dots (NGQDs) have been discovered to significantly amplify the ECL emission and increase the ECL efficiency of Ru(dcbpy) for the first time. However, the mechanism by which NGQDs act as coreactants is not well comprehended.
View Article and Find Full Text PDFNanotechnology
January 2025
Department of Electrical and Computer Engineering, Nazarbayev University, Nazarbayev University, Astana, Kazakhstan, Astana, 010000, KAZAKHSTAN.
Non-equilibrium molecular dynamics (NEMD) simulations reveal the existence of a spontaneous heat current (SHC) in the absence of a temperature gradient and demonstrate ultra-high thermal rectification in asymmetric trapezoid-shaped graphene. These unique properties have potential applications in power generation and thermal circuits, functioning as thermal diodes. Our findings also show the presence of negative and zero thermal conductivity in this system.
View Article and Find Full Text PDFAnal Methods
January 2025
Department of Nutrition and Dietetics, Faculty of Health Sciences, Hasan Kalyoncu University, Gazi-antep, 27000, Turkey.
In the present study, a novel voltammetric sensor based on a boron-doped copper oxide/graphene (B-CuO-Gr) nanocomposite and molecularly imprinted polymer (MIP) was developed for the detection of paclobutrazol (PAC) in apple and orange juice samples. The B-CuO-Gr nanocomposite was prepared using sol-gel and calcination methods. After modifying glassy carbon electrodes with the B-CuO-Gr nanocomposite, PAC-imprinted electrodes were prepared in the presence of 100.
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