An ultrasensitive label-free electrochemical aptasensor was developed for selective detection of chloramphenicol (CAP). The aptasensor was made using screen-printed gold electrode modified with synthesized gold nano cube/cysteine. The interactions of CAP with aptamer were studied by cyclic voltammetry, square wave voltammetry (SWV) and electrochemical impedance spectroscopy. Under optimized conditions, two linear calibration curves were obtained for CAP determination using SWV technique, from 0.03 to 0.10 µM and 0.25– 6.0 µM with a detection limit of 4.0 nM. The aptasensor has the advantages of good selectivity and stability and applied to the determination of CAP in human blood serum sample.
