Single-walled carbon nanotubes (SWCNTs) illuminated by white light should appear colored due to resonance Rayleigh scattering. However, true-color imaging of SWCNTs on substrates has not been reported, because of the extremely low scattering intensity of SWCNTs and the strong substrate scattering. Here we show that Rayleigh scattering can be greatly enhanced by the interface dipole enhancement effect. Consequently colorful SWCNTs on substrates can be directly imaged under an optical microscope by wide field supercontinuum laser illumination, which facilitates high throughput chirality assignment of individual SWCNTs. This approach, termed "Rayleigh imaging microscopy", is not restricted to SWCNTs, but widely applicable to a variety of nanomaterials, which enables the colorful nanoworld to be explored under optical microscopes.

The optical effect of a nanometer or sub-nanometer interfacial layer of condensed molecules surrounding individual nanomaterials such as single-walled carbon nanotubes (SWCNTs) has been studied theoretically and experimentally. This interfacial layer, when illuminated by light, behaves as an optical dipole lattice and contributes an instantaneous near field which enhances the local field on neighboring atoms, molecules, or nanomaterials, which in turn may lead to enhanced Rayleigh scattering, Raman scattering, and fluorescence. The theory of this interface dipole enhanced effect (IDEE) predicts that a smaller distance between the nanomaterials and the plane of the interfacial layer, or a larger ratio of the dielectric constants of the interfacial layer to the surrounding medium, will result in a larger field enhancement factor. This prediction is further experimentally verified by several implementations of enhanced Rayleigh scattering of SWCNTs as well as in situ Rayleigh scattering of gradually charged SWCNTs. The interface dipole enhanced Rayleigh scattering not only enables true-color real-time imaging of nanomaterials, but also provides an effective means to peer into the subtle interfacial phenomena.