A novel electrochemical sensor for interleukin-8 (IL-8) detection based on Fe 3 O 4 @ graphene oxide (GO) @ molecularly imprinted polymer (MIP) nanoparticles was constructed. IL-8 was surface imprinted on the GO modified super-paramagnetic Fe 3 O 4 nanoparticles and the synthesized Fe 3 O 4 @GO@MIP nanoparticles were self assembled onto the Au film electrode under magnetic field. Scanning electron microscopy-energy dispersive X-ray was used to characterize the core-shell structure of the nanoparticles. Cyclic 10 voltammetry measurement was used to monitor the electrochemical process and its optimization, which illustrated that IL-8 could selectively bind to the Fe 3 O 4 @GO@MIP nanoparticle based sensor and cause a decrease of the measured current (the higher concentration of IL-8, the larger decrease of the current). The results revealed that the sensor displayed superb resistance to non-specific binding, very attractive detection limit as low as 0.04 pM, and a wide linear range from 0.1 to 10 pM towards IL-8. Furthermore, the sensor was also successfully used for the detection of IL-8 in saliva. Therefore, the Fe 3 O 4 @GO@MIP nanoparticle based sensor might 15 provide a sensitive, rapid, selective and cost-effective method for IL-8 determination and related cancer marker analysis.