High-throughput determination of lipopolysaccharide by flow injection analysis using dipicolylamine-type fluorescent probe
Hiroshi Kimoto,
Yuya Hirahara,
Kai Sato,
Masamitsu Iiyama,
Takeshi Hashimoto,
Takashi Hayashita
Affiliations
Hiroshi Kimoto
Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo 102-8554, Japan; Technical Development Division, Nomura Micro Science Co., Ltd., Atsugi, Kanagawa 243-0021, Japan
Yuya Hirahara
Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo 102-8554, Japan; Technical Development Division, Nomura Micro Science Co., Ltd., Atsugi, Kanagawa 243-0021, Japan
Kai Sato
Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo 102-8554, Japan
Masamitsu Iiyama
Technical Development Division, Nomura Micro Science Co., Ltd., Atsugi, Kanagawa 243-0021, Japan
Takeshi Hashimoto
Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo 102-8554, Japan
Takashi Hayashita
Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo 102-8554, Japan; Corresponding author.
Endotoxin (lipopolysaccharide: LPS), a bacterial toxin, is currently quantified by batch analysis using a reagent made from Limulus amebocyte lysate (LAL). Although the LAL method is sensitive, a long measurement time and gelation have hindered its application to online water quality monitoring. In this paper, we report a novel high-throughput analytical technique that combines flow injection analysis (FIA) and a dipicolylamine-type fluorescent probe, which was previously reported to exhibit strong fluorescence emission in response to LPS. A comparison of normal and reverse FIA systems revealed that the normal FIA offers more rapid detection with throughput of 30 samples per hour, which is the highest among known LAL methods and alternative LPS detection methods that have been recently reported. On the other hand, the reverse FIA requires much less reagent (480 μL per sample). Continuous online monitoring of water quality and analysis of real samples spiked with LPS were realized by this technique.
