Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan.
Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore 632 014, India.
Biosensors (Basel). 2022 May 24;12(6):360. doi: 10.3390/bios12060360.
A simple, one-step and facile method has been introduced to prepare fluorescent and electrochemically active carbon nanoparticles with single-size distribution and good long-term stability by electrochemical exfoliation of polyacrylonitrile-based carbon fibers in an alkaline solution-phase condition. The preparation condition was systematically optimized by studying the effect of temperature and electrolytes. It has been found that an electrochemical exfoliation reaction carried out at an applied potential of 2 V vs. Ag/AgCl in a phosphate-ion-containing alkaline solution at a temperature of 40 °C is an ideal condition for the preparation of 14 ± 4 nm-sized carbon nanoparticles. Unlike the literature protocols, there are no filtration and membrane dialysis-based off-line sample pretreatments adopted in this work. The as-prepared carbon nanoparticles were characterized by fluorescence, Raman spectrum, transmission electron microscope, and X-ray photoelectron spectroscopic characterization methods. It was found that the carbon-oxygen functional group rich in graphene-oxide quantum dots (GOQDs) such as carbon nanoparticles were formed in this work. A preliminary study relating to simultaneous electrochemical oxidation and the sensing of uric acid and ascorbic acid with well-resolved peaks was demonstrated as a model system to extend the new carbon material for electroanalytical applications. Furthermore, in situ synthesis of 2 nm-sized gold nanoparticles stabilized by GOQDs was presented. The carbon nanoparticles prepared by the direct method in this work have shown good stability over 6 months when stored at room temperature. The electrochemical exfoliation reaction has been found to be highly reproducible and suitable for bulk synthesis of luminescence-effective carbon nanoparticles to facilitate fundamental studies and practical applications.
一种简单、一步法和简便的方法已经被引入，通过在碱性溶液相条件下电化学剥离基于聚丙烯腈的碳纤维，来制备具有单分散尺寸和良好长期稳定性的荧光和电化学活性碳纳米粒子。通过研究温度和电解质的影响，系统地优化了制备条件。已经发现，在 40°C 的温度下，在含有磷酸盐离子的碱性溶液中，在 2 V 对 Ag/AgCl 的施加电位下进行的电化学剥离反应是制备 14±4nm 尺寸的碳纳米粒子的理想条件。与文献方案不同，在这项工作中没有采用基于过滤和膜透析的离线样品预处理。所制备的碳纳米粒子通过荧光、拉曼光谱、透射电子显微镜和 X 射线光电子能谱表征方法进行了表征。结果发现，在这项工作中形成了富含氧化石墨烯量子点（GOQDs）的碳纳米粒子等富碳-氧官能团。作为一个模型系统，展示了同时电化学氧化和尿酸及抗坏血酸的传感的初步研究，以扩展新的碳材料用于电分析应用。此外，还提出了由 GOQDs 稳定的 2nm 尺寸的金纳米粒子的原位合成。通过直接法制备的碳纳米粒子在室温下储存 6 个月时表现出良好的稳定性。已经发现电化学剥离反应具有高度重现性，适合于发光有效碳纳米粒子的批量合成，以促进基础研究和实际应用。
