Constructing a nanoelectrode for an individual nanoparticle and realizing the spectral characterization and modulation simultaneously have profound significances for fabricating nano-optoelectronic devices. This paper proposes and prepares the nanostructure made up of gold (Au) interdigital electrodes loaded with barium titanate (BaTiO₃) nanoparticles, thereby physically couples surface plasmon polariton mode of collective grating with Mie resonance of BaTiO₃ nanoparticles and local surface plasmon resonance mode at the interface of Au-BaTiO₃. Therefore, the scattering modulation and characterization of individual BaTiO₃ nanoparticles with a diameter less than 200 nm loaded on interdigital electrodes are realized. The platform uses the grating structure as the "background screen", which overcomes the undesired scattering signal from the whole electrode structure and solves the problem for detecting the scattering signal of individual nanoparticle when combined with electrodes. BaTiO₃ nanoparticle-based nanopixels with diameters less than 200 nm exhibit tunable scattering spectra in the visible range depending on grating size and polarization, which provides an approach for further building tunable optoelectronic devices based on single nanoparticle.