Abstract: An optical component may be optically blackened so that the surface of the component is not reflective when light impinges upon the surface. In some examples, a method of blackening involves exposing a surface of the optical component that defines an optical pathway to an optical blackening composition for a period of time effective to optically blacken the surface. The optical blackening composition may be configured so that the resulting optically blackened optical pathway is non-fluorescing when exposed to ultraviolet light. In some examples, the optical blackening composition comprises selenous acid and is devoid of organic molecules.

Abstract: An optical component may be optically blackened so that the surface of the component is not reflective when light impinges upon the surface. In some examples, a method of blackening involves exposing a surface of the optical component that defines an optical pathway to an optical blackening composition for a period of time effective to optically blacken the surface. The optical blackening composition may be configured so that the resulting optically blackened optical pathway is non-fluorescing when exposed to ultraviolet light. In some examples, the optical blackening composition comprises selenous acid and is devoid of organic molecules.

Abstract: Provided are surface-enhanced Raman spectroscopy (SERS) devices suitable for intra-subject (e.g., intracellular) observation, which devices may be of nanoscale size. Also provided are related SERS analysis methods.