Plasmon-enhanced fluorescence provided by silver nanoprisms for sensitive detection of sulfide

Noble metallic nanostructures, such as silver, play an important role in fluorescent enhancement. In this paper, a serial of silver nanoprisms were fabricated by using seed-mediated growth method, and their surface plasmon resonance (SPR) peak could be controlled from 500 nm to 900 nm through adjusting the volume of silver seed solution. Then three kinds of as-prepared silver nanoprisms were conjugated with Atto550 by using polymer COOH-PEG-SH and streptavidin-biotin bond. It is proved that all these three silver nanoprisms present good ability in enhancing the fluorescent intensity of Atto550, especially the one with SPR peak at 570 nm, which results in almost ten times enhancement of the fluorescent intensity. By using Atto550 functionalized silver nanoprisms (SPR 570 nm), an "off" sensor has been designed, which shows excellent ability in quantitatively detecting sulfide in aqueous solution.