A fluorescent sensor base on magnetic silica nanoparticles for Cu2+ and pyrophosphate mimicking IMPLICATION logic gate

In this work, we developed a molecular logic gate system (NTPA-Fe3O4@SiO2) based on the multifunctional magnetic silica nanoparticles, using Cu2+ and pyrophosphate (PPi) as inputs. These multifunctional nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), elementary analysis, X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), thermal gravimetric analysis (TGA), UV–visible absorption and fluorescence measurement. UV–visible absorption and fluorescence spectra revealed that NTPA-Fe3O4@SiO2 displayed high selectivity for Cu2+, and the complexation of Cu2+ with NTPA-Fe3O4@SiO2 (Cu-NTPA-Fe3O4@SiO2) exhibited selective recognition towards PPi. Moreover, the fluorescence emission changes of NTPA-Fe3O4@SiO2 by the inputs of Cu2+ and PPi can be viewed as an IMPLICATION logic gate at the nanoscale level.