A great promise for nanotechnology in medical applications has focused on the development of different forms of nanoparticles for cancer therapy.However,for further biomedical applications,these nanoparticles should not only be high colloidal stable and biocompatible in the physiological environment,but also present targeting to tumor cells.We explore to solve this problem by surface tailoring of nanoparticles via mixed-charge SAM,which can provide a facile method to present better "stealth" properties and higher accumulation in tumor than PEG-2000 modified nanoparticles.Combing with the pH-responsive properties of weak electrolytes,the mixed charge bionanointerface can be explored as a robust method to control the aggregation of NPs sensitive to enhance the retention and cellular uptake of inorganic NPs in tumors,which has perfect stealth properties and pH-sensitivity for tumor targeting and photothermal treatment.