Electrochemical impedance sensor based on Au nanoparticles and polydopamine functionalized on reduced graphene oxide for atenolol detection

Atenolol has been used as a first-line treatment for hypertension. It is also widely used for the treatment of cardiovascular disease, including myocardial infarction, angina pectoris and arrhythmia. Atenolol needs periodic checking to adjust its dosage due to its wide therapeutic range [۱-۳]. Therefore, accurate and sensitive analytical methods are necessary for analysis of the drug in biological fluids. In this study, we designed and fabricated an electrochemical impedance sensor based on Au nanoparticles and reduced graphene oxide modified with polydopamine (AuNPs/PDA-rGO) for the detection of atenolol drug. AuNPs/PDA-rGO nanocomposite characterized with surface and electrochemical techniques. Atenolol have amine and hydroxyl groups that are protonated in an acidic environment and can be placed on the surface of AuNPs through electrostatic interactions and increase the resistance of the electrode surface compared to the absence of atenolol. The increased resistance is proportional to the concentration of atenolol, which can be recorded as an electrochemical signal with electrochemical impedance spectroscopy (EIS) method in electrochemical probe (Fe(CN)۶۳-/۴-). The constructed sensor exhibits good linearity from ۵.۰×۱۰-۱۲ to ۵.۰×۱۰-۹ mol L-۱. The detection limitation of ۱.۲×۱۰-۱۲ mol L-۱ was achieved. The proposed sensor was successfully applied to the determination of atenolol in pharmaceutical samples, and human serum as real samples. Acceptable recoveries of analyte from samples clearly shown that the proposed sensor is good applicable to clinical analysis, quality control and a routine determination of drugs in pharmaceutical formulations.