Young Researchers and Elite Club, Central Tehran Branch, Islamic Azad University (IAUCTB), Tehran, Iran.
PLoS One. 2013 Nov 26;8(11):e79254. doi: 10.1371/journal.pone.0079254. eCollection 2013.
Graphene oxide (GO) nanoparticle is a high potential effective absorbent. Tetracycline (TC) is a broad-spectrum antibiotic produced, indicated for use against many bacterial infections. In the present research, a systematic study of the adsorption and release process of tetracycline on GO was performed by varying pH, sorption time and temperature. The results of our studies showed that tetracycline strongly loads on the GO surface via π-π interaction and cation-π bonding. Investigation of TC adsorption kinetics showed that the equilibrium was reached within 15 min following the pseudo-second-order model with observed rate constants of k2 = 0.2742-0.5362 g/mg min (at different temperatures). The sorption data has interpreted by the Langmuir model with the maximum adsorption of 323 mg/g (298 K). The mean energy of adsorption was determined 1.83 kJ/mol (298 K) based on the Dubinin-Radushkevich (D-R) adsorption isotherm. Moreover, the thermodynamic parameters such as ΔH°, ΔS° and ΔG° values for the adsorption were estimated which indicated the endothermic and spontaneous nature of the sorption process. The electrochemistry approved an ideal reaction for the adsorption under electrodic process. Simulation of GO and TC was done by LAMMPS. Force studies in z direction showed that tetracycline comes close to GO sheet by C8 direction. Then it goes far and turns and again comes close from amine group to the GO sheet.
氧化石墨烯（GO）纳米粒子是一种高潜力的有效吸附剂。四环素（TC）是一种广谱抗生素，用于治疗多种细菌感染。在本研究中，通过改变 pH 值、吸附时间和温度，对四环素在 GO 上的吸附和释放过程进行了系统研究。研究结果表明，四环素通过π-π相互作用和阳离子-π键强烈负载在 GO 表面。TC 吸附动力学研究表明，在 15 分钟内达到平衡，符合准二级动力学模型，观察到的速率常数 k2为 0.2742-0.5362 g/mg min（在不同温度下）。吸附数据通过 Langmuir 模型进行解释，最大吸附量为 323 mg/g（298 K）。根据 Dubinin-Radushkevich（D-R）吸附等温线，确定平均吸附能为 1.83 kJ/mol（298 K）。此外，还估算了吸附的热力学参数，如ΔH°、ΔS°和ΔG°值，表明吸附过程是吸热和自发的。电化学证明了在电极过程中吸附是一种理想的反应。通过 LAMMPS 对 GO 和 TC 进行了模拟。在 z 方向上的力研究表明，四环素通过 C8 方向接近 GO 片。然后它远离并转向，再次从胺基团接近 GO 片。
