I will discuss advances in tip-enhanced spectroscopy in sensitivity, selectivity, time resolution, and overall parameter space in particular for Raman, photoluminescence, and nonlinear nano-imaging. In particular to gain insight into intra- and inter-molecular coupling and dynamics, we use tip-enhanced Raman spectroscopy (TERS) at variable and cryogenic temperatures, to slow and control the motion of a single-molecule. We resolve intrinsic linewidths of individual normal modes, allowing detailed and quantitative investigation of the vibrational fingerprint.

From temperature dependent line narrowing and splitting, we quantify ultrafast vibrational dephasing and intramolecular coupling. Through statistical correlation analysis of fluctuations of individual modes, we observe rotational dynamics and spectral diffusion of the molecule. In two-dimensional (2D) materials the physical properties are strongly influenced by nanoscale heterogeneities in the form of nucleation sites, defects, and edges. From combined tip-enhanced Raman scattering (TERS) and photoluminescence (TEPL) spectroscopy and imaging we resolve the nonlocal correlation and influence of grain boundaries and edges on structure and electronic excitation with sub-20 nm spatial resolution. From active AFM tip control and release of built in crystal strain we can assign PL spectral position and intensity to nanoscale strain effect.