The controllable manipulation of bandgap, radiative emission, and energy transfer in low-dimensional quantum materials provides a versatile platform for a range of quantum photonic devices. Moreover, the understanding and precise regulation of nanoscale behaviors exhibited by excitonic quasiparticles, such as excitons and trions, in low-dimensional semiconductors are paramount for the development of highly efficient nano-excitonic devices. In this talk, we introduce a tip-induced nano-spectroscopic approach for dynamically controlling light-matter interactions at the nanoscale. We then demonstrate a series of tip-induced nano-engineering experiments exhibiting plasmon-exciton interactions in quantum dots and atomically thin semiconductors. Our research shows a novel strategy for the creation of robust, tunable, and ultracompact nano-excitonic devices utilizing low-dimensional semiconductors.