Aghajari Rozita, Azadbakht Azadeh
Department of Chemistry, Khorramabad Branch, Islamic Azad University, Khorramabad, Iran.
Department of Chemistry, Khorramabad Branch, Islamic Azad University, Khorramabad, Iran.
Anal Biochem. 2018 Apr 15;547:57-65. doi: 10.1016/j.ab.2018.02.005. Epub 2018 Feb 8.
A streptomycin-specific aptamer was used as a receptor molecule for ultrasensitive quantitation of streptomycin. The glassy carbon (GC) electrode was modified with palladium nanoparticles decorated on chitosan-carbon nanotube (PdNPs/CNT/Chi) and aminated aptamer against streptomycin. Modification of the sensing interface was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray (EDS), wavelength-dispersive X-ray spectroscopy (WDX), cyclic voltammetry (CVs), and electrochemical impedance spectroscopy (EIS). The methodologies applied for designing the proposed biosensor are based on target-induced conformational changes of streptomycin-specific aptamer, leading to detectable signal change. Sensing experiments were performed in the streptomycin concentration range from 0.1 to 1500 nM in order to evaluate the sensor response as a function of streptomycin concentration. Based on the results, the charge transfer resistance (R) values increased proportionally to enhanced streptomycin content. The limit of detection was found to be as low as 18 pM. The superior selectivity and affinity of aptamer/PdNPs/CNT/Chi modified electrode for streptomycin recognition made it favorable for versatile applications such as streptomycin analysis in real samples.
一种链霉素特异性适配体被用作链霉素超灵敏定量的受体分子。玻碳（GC）电极用修饰在壳聚糖 - 碳纳米管上的钯纳米颗粒（PdNPs/CNT/Chi）和抗链霉素的胺化适配体进行修饰。通过扫描电子显微镜（SEM）、能量色散X射线（EDS）、波长色散X射线光谱（WDX）、循环伏安法（CVs）和电化学阻抗谱（EIS）对传感界面的修饰进行表征。所提出的生物传感器设计所采用的方法基于链霉素特异性适配体的目标诱导构象变化，从而导致可检测的信号变化。为了评估传感器响应与链霉素浓度的函数关系，在0.1至1500 nM的链霉素浓度范围内进行传感实验。基于结果，电荷转移电阻（R）值与链霉素含量的增加成比例增加。检测限低至18 pM。适配体/PdNPs/CNT/Chi修饰电极对链霉素识别具有优异的选择性和亲和力，使其有利于在实际样品中的链霉素分析等多种应用。
