Plant tissue-based chemiluminescence flow biosensor for oxalate

A novel plant tissue-based chemiluminescence (CL) biosensor for oxalate com bined with flow injection analysis is proposed in this paper. The analytica l reagents involved in the CL reaction, including luminol and cobalt(II), w ere both immobilized on an ion exchange resin column, while the biological material spinach tissue was packed in a mini-glass column. By the oxalate o xidase-catalyzed reaction in the plant tissue column, hydrogen peroxide was produced, which could react with luminol and cobalt(II) being released fro m the ion exchange column by hydrolysis to generate a CL signal. The CL emi ssion intensity was linear with oxalate concentration in the range 0.6-100 mu M and the detection limit was 0.2 mu M. The biosensor was stable for 300 determinations and a complete analysis, including sampling and washing, co uld be performed in 2 min with a relative standard deviation of less than 5 %.