Department of Chemistry, Sri Eshwar College of Engineering (Autonomous), Coimbatore, 641 202, Tamil Nadu, India.
Department of Chemistry, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, South Korea.
Mikrochim Acta. 2023 May 27;190(6):242. doi: 10.1007/s00604-023-05804-0.
Binder-free and efficient electrochemical sensing of levofloxacin (LF) was successfully developed based on the nitrogen-doped carbon nanodots (NCNDs). The NCNDs were synthesized by hydrothermal carbonation (180°C for 12 h), and the heteroatom was embedded in aqueous solution of ammonia (NH). Spectral and microscopic characteristization techniques were used to analyze the topological, crystallinity, and chemical binding behavior of synthesized biomass functional material. HR-TEM image revealed a uniform spherical dot (2.96 nm), and superior quantum yield efficiency (0.42 Φ). The NCNDs was drop coated on a glassy carbon electrode (GCE) and electrochemical sensing of LF was performed by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometric i-t curve in phosphate-buffered saline (PBS; pH = 7.0). The NCNDs modified electrode showed a sharp oxidation peak at +0.95 V (vs. Ag/AgCl) with a four-fold higher current response than the bare GC electrode. The NCNDs/GCE surface not only increases the current response, but has lower detection potential, and facilitates electron transfer reaction. Under optimized working parameters, the NCNDs/GCE showed wide linear concentrations range from 200 nM to 2.8 mM and a low detection limit (LOD) of 48.26 nM (S/N = 3). The electrode modified with NCNDs has high electrochemical sensing stability (RSD = 1.284 ± 0.05% over 5 days), and superior reproducibility (RSD = 1.682 ± 0.06% (n = 3)). Finally, the NCNDs modified GC electrode was successfully applied to quantify the concentration of LF in drug and river water samples with acceptable recovery percentages of 96.60-99.20% and 97.20-99.00% (n=3), respectively.
基于氮掺杂碳纳米点（NCNDs），成功开发了无粘结剂且高效的左氧氟沙星（LF）电化学传感器。NCNDs 通过水热碳化（180°C 12 h）合成，杂原子嵌入氨水溶液（NH）中。光谱和微观特征分析技术用于分析合成生物质功能材料的拓扑结构、结晶度和化学结合行为。高分辨率透射电子显微镜（HR-TEM）图像显示出均匀的球形点（2.96 nm）和较高的量子产率效率（0.42 Φ）。NCNDs 被滴涂在玻碳电极（GCE）上，并通过循环伏安法（CV）、差分脉冲伏安法（DPV）和安培计时电流曲线在磷酸盐缓冲盐水（PBS；pH = 7.0）中进行 LF 的电化学传感。NCNDs 修饰电极在 +0.95 V（相对于 Ag/AgCl）处显示出尖锐的氧化峰，比裸 GCE 的电流响应高四倍。NCNDs/GCE 表面不仅增加了电流响应，而且具有更低的检测电位，有利于电子转移反应。在优化的工作参数下，NCNDs/GCE 显示出从 200 nM 到 2.8 mM 的宽线性浓度范围和低检测限（LOD）为 48.26 nM（S/N = 3）。修饰有 NCNDs 的电极具有高电化学传感稳定性（在 5 天内 RSD = 1.284 ± 0.05%）和出色的重现性（RSD = 1.682 ± 0.06%（n = 3））。最后，成功地将 NCNDs 修饰的 GC 电极应用于药物和河水样品中 LF 浓度的定量分析，回收率分别为 96.60-99.20%和 97.20-99.00%（n = 3）。
