The present invention relates to emulsion-templated silica micro and nano-capsules- and methods for making them. In particular, the template emulsion is stabilized by a biosurfactant that also assists in nucleating the silica shell Mineralizing biosurfactants and stabilized micro- and nano-emulsions useful in forming the emulsion-templated micro- and nano-capsules, and methods for the use of the silica micro- and nano-capsules are also described.