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Highly selective and sensitive detection of catecholamines using NaLuGdF4:Yb3+/Er3+ upconversion nanoparticles decorated with metal ions
摘要： We developed a novel optical sensor for sensitive and selective detection of catecholamines based on upconversion nanoparticles (UCNPs) decorated with different metal ions (UCNP-Men+). 1,2-ethanedithiol was chosen as a surface additive to synthesize the NaLuGdF4:Yb3+/Er3+ UCNPs by one-step at 200 °C. The as-prepared UCNPs exhibited a strong emission under the continuous excitation at 980 nm. It was found that catecholamines could be more effectively detected in the presence of UCNP-Fe3+, whereas, dopamine and epinephrine were detected selectively using UCNP-Li+ and UCNP-Cu2+ sensors, respectively. Under the optimum conditions, the limit of detections (LODs) for catecholamines, dopamine, and epinephrine are 2.8, 2.5, and 2.4 nM, respectively, with good linearity in the range of 5–320 nM for total catecholamines and 5–30 nM for dopamine and epinephrine. The developed method has been successfully applied to detect dopamine and epinephrine in human urine samples with good accuracy and satisfactory recovery.
关键词： Upconversion nanoparticles,Human urine,Metal ion decorated,Catecholamines,1,2-ethanedithiol
更新于2025-09-23 15:23:52
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Influence of the supramolecular arrangement of iron phthalocyanine thin films on catecholamine oxidation
摘要： The versatility of iron phthalocyanine (FePc) to form distinct supramolecular arrangements in thin films, characterized by their thickness, molecular organization, morphology, and crystallinity, can be used to tune the electrochemical oxidation of catecholamines, becoming a promising material for sensing applications. Here, Langmuir-Schaefer (LS) and electrodeposition (ED) techniques have been used to produce thin films of FePc with different supramolecular arrangements on ITO electrodes. Both types of modified electrode were evaluated for the electrochemical oxidation of L-Dopa, dopamine (DA), norepinephrine (NEp), and epinephrine (Ep) in aqueous solution. The effect of scan rate, potential range, presence of oxygen, and pH were also evaluated, having an influence on the electrochemical oxidation of catecholamines. The FePc/ED modified electrodes showed two distinct peaks in the presence of mixtures of DA/L-Dopa and DA/Ep, while for FePc/LS modified electrodes an overlap of the oxidation waves was observed. This behaviour reveals the influence of the supramolecular arrangement of FePc on catecholamine oxidation. The FePc/LS modified electrodes showed a limit of detection of 0.024 μmol L-1 for DA and 0.168 μmol L-1 for L-Dopa, while FePc/ED showed limits of detection of 0.288 μmol L-1 and 0.564 μmol L-1, respectively. The FePc films showed suitable properties for future application as catecholamine sensors.
关键词： electrodeposition,Langmuir-Schaefer,iron phthalocyanine,catecholamines
更新于2025-09-23 15:23:52
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A new nanocomposite optical sensor based on polyurethane foam and gold nanorods for solid-phase spectroscopic determination of catecholamines
摘要： A new nanocomposite material based on gold nanorods and polyurethane foam was obtained, and a method for the determination of catecholamines with the use of this nanocomposite modified with silver nitrate was developed. The determination is based on the measuring hypsochromic shift of a short-wave surface plasmon resonance band in a diffuse reflection spectrum of the nanocomposite. This shift is caused by reduction of silver from silver ions on the surface of gold nanorods under the influence of catecholamines. Effects of time, pH, volume of the reaction mixture, concentration of silver ions, and catecholamines on the interaction were examined. The proposed method allows to determine dobutamine, epinephrine, norepinephrine and dopamine with the detection limits of 0.1, 0.07, 0.07, and 0.05 μg mL?1, respectively. The developed method can be applied to analysis of medicines.
关键词： Nanocomposite,Au nanorods,Surface plasmon resonance,Polyurethane foam,Catecholamines,Solid-phase spectroscopy
更新于2025-09-12 10:27:22