An electrochemical sensor based on iron(ii,iii)@graphene oxide@molecularly imprinted polymer nanoparticles for interleukin-8 detection in saliva†
Abstract
A novel electrochemical sensor for interleukin-8 (IL-8) detection based on Fe3O4@graphene oxide (GO)@molecularly imprinted polymer (MIP) nanoparticles was constructed. IL-8 was surface imprinted on GO modified super-paramagnetic Fe3O4 nanoparticles and the synthesized Fe3O4@GO@MIP nanoparticles were self-assembled onto a Au film electrode under a magnetic field. Scanning electron microscopy-energy dispersive X-ray spectroscopy was used to characterize the core–shell structure of the nanoparticles. Cyclic voltammetry measurements were used to monitor the electrochemical process and its optimization, which illustrated that IL-8 could selectively bind to the Fe3O4@GO@MIP nanoparticle based sensor and cause a decrease of the measured current (the higher the concentration of IL-8, the larger the decrease of the current). The results revealed that the sensor displayed superb resistance to non-specific binding, a 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 Fe3O4@GO@MIP nanoparticle based sensor might provide a sensitive, rapid, selective and cost-effective method for IL-8 determination and related cancer marker analysis.