In the present research, a nanoaptasensor is proposed for electrochemical measurement of chloramphenicol (CAP). To this purpose, the nanocomposite prepared from graphene oxide and functionalized with (3‐Aminopropyl) triethoxysilane/silver nanoparticles to the abbreviated AgNPs/[NH2–Si]-f-GO, was utilized to modify the glassy carbon electrode (GCE). Furthermore, the modified electrode was also investigated using the electrochemical methods such as electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The AgNPs/[NH2–Si]-f-GO nanocomposite was investigated by UV–Vis spectrophotometry. Fourier transform infrared (FT-IR) spectrometry and transmission electron microscopy (TEM). Moreover, [Fe(CN)6]3-/4 solution in the role of an electrochemical probe was applied. The AgNPs/ [NH2–Si]-f-GO nanocomposite was confirmed as a good layer to covalent immobilization of aptamer (Apt) onto the GCE surface. In this sense, the DPV was used as a sensitive electrochemical technique for the measurement of CAP with an appropriate linear concentration range which was found to be between 10 pM and 0.2 μM and, with a low limit of detection, it equaled 3.3 pM. CAP which was identified in the presence of other usual antibiotics existed in the real samples.
