However, the most striking observation came while running a control experiment in which they replaced the reducing agent — which ordinarily releases the gold particles — with microdroplets of water. (sciencedaily.com)
Indeed, the team observed that gold nanoparticle grew over 100,000 times faster in microdroplets. (sciencedaily.com)
It's still unclear why water microdroplets are able to replace a reducing agent in this reaction. (sciencedaily.com)