Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
Biosensors (Basel). 2022 Oct 21;12(10):906. doi: 10.3390/bios12100906.
A new electrochemical sensor for the detection of levofloxacin (LV) was efficiently realized. The aim was to develop a new, cheap, and simple sensor for the detection of LV, which is used in various infections due to its pharmacological importance. It consists of carbon paste (CP) enhanced with nano-sized fumed silica (NFS). NFS has a very low bulk density and a large surface area. The carbon paste-enhanced NFS electrode (NFS/CPE) showed great electrocatalytic activity in the oxidation of 1.0 mM LV in Britton-Robinson buffer (BR) at pH values ranging from 3.0 to 8.0. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used; the peak current value (I) of the NFS/CPE sensor was 2.7 times that of the bare electrode, ensuring its high electrocatalytic activity. Electrochemical impedance spectroscopy (EIS) was performed at a peak potential (E) of +1066 mV, yielding a resistance of 10 kΩ for the designed NFS/CPE sensor compared to 2461 kΩ for the bare electrode, indicating the high conductivity of the modified sensor and verifying the data observed using the CV technique. Surface descriptions were determined by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The variation in the concentration of LV (2.0 to 1000 µM) was considered in BR buffer (pH = 5.0) at a scan rate (SR) of 10 mV/s by the NFS/CPE. The detection and quantification limits were 0.09 µM and 0.30 µM, respectively. To evaluate the application of LV in real samples, this procedure was established on Quinostarmax 500 mg tablets and human plasma samples. Reasonable results were obtained for the detection of LV.
一种用于检测左氧氟沙星（LV）的新型电化学传感器得到了有效实现。该研究旨在开发一种新的、廉价且简单的传感器，用于检测 LV，由于其药理学重要性，LV 被用于各种感染。该传感器由碳糊（CP）增强纳米级气相法二氧化硅（NFS）组成。NFS 的体密度非常低，表面积非常大。在 pH 值为 3.0 至 8.0 的 Britton-Robinson 缓冲液（BR）中，碳糊增强的 NFS 电极（NFS/CPE）对 1.0 mM LV 的氧化具有出色的电催化活性。使用循环伏安法（CV）和差分脉冲伏安法（DPV）；NFS/CPE 传感器的峰值电流值（I）是裸电极的 2.7 倍，确保了其高电催化活性。在峰值电位（E）为+1066 mV 时进行了电化学阻抗谱（EIS），与裸电极的 2461 kΩ 相比，设计的 NFS/CPE 传感器的电阻为 10 kΩ，表明改性传感器具有高导电性，并验证了使用 CV 技术观察到的数据。通过扫描电子显微镜（SEM）和能量色散 X 射线分析（EDX）进行了表面描述。在 BR 缓冲液（pH = 5.0）中，以 10 mV/s 的扫描速率（SR）考虑了 LV（2.0 至 1000 µM）浓度的变化。检测限和定量限分别为 0.09 µM 和 0.30 µM。为了评估 LV 在实际样品中的应用，该方法建立在 Quinostarmax 500 mg 片剂和人血浆样品上。对于 LV 的检测，得到了合理的结果。
