The frequency of an alternating magnetic field acting on multiwall carbon nanotubes decorated with Pt nanoparticles was identified as a change in conductance. The samples were prepared in film form using chemical vapor deposition and Pt nanoparticles were grown with acid precursors. Sample characterizations were analyzed by transmission and scanning electron microscopies. In a conductance dependent temperature measurement, the sample exhibits a non-metallic behavior. A Bode analysis shows a relocation on the controllable poles in the magneto-conductive activity. Moreover, optical nonlinearities were studied by single-beam and two-wave mixing configurations in the nanosecond regime. The optical absorbance dependent on irradiance and magnetic field was analytically described. Significant changes in two-wave mixing experiment were observed by magnetic perturbation. Sensitive magnetoplasmonic interactions by adding Pt nanoparticles on carbon nanotubes were responsible for enhancing magnetic and nonlinear optical effects. Immediate applications for scalable magnetophotonic systems in quantum sensing can be contemplated.