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Surface behavior of nanopores is important to the molecular sensing of nanopore, which can enhance the translocation events of particles through nanopore.The silicon nitride nanopores were fabricated by FIB and the surface was derivatized with 3-aminopropyltriethoxysilane to change its surface charge density, which was characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), current-voltage (Ⅰ-Ⅴ) curve.The electrophoretic translocation of charged PS nanoparticles (diameter 100 nm) was investigated in solution using the Coulter counter principle in which the time-dependent nanopore current was recorded as the nanoparticles were driven across nanopore.The positively charged surface attracted nanoparticles when they were in the vicinity of nanopore.The capture rate was calculated about 3.34 events/s.Translocation behaviors and several kinds of event types were analyzed in different biased voltages.A linear dependence has been found between current drop and biased voltage.In conclusion, the surface modified nanopore is better applied for sensing nanoparticles in solution.