Plant tissue-based chemiluminescence flow biosensor for the determination of oxalate

A novel chemiluminescence (CL) biosensor for the determination of oxalate i s presented in this paper, It is based on the CL reaction between luminol, immobilized on an anion-exchange column, and hydrogen peroxide generated on -line via oxalate by the catalytic effect of oxalate oxidase in spinach in the flow cell. The biosensor responds linearly to oxalate concentration in the range of 4.0X10(-7) to 1.0X10(-4) mol/L, and the detection limit is 2X1 0(-7) mol/L. A complete analysis could be performed in 1 min with a relativ e standard deviation of 3.7% for 1.0X10(-5) mol/L oxalate(n=7). The system is stable for over 200 times determinations and has been applied in urine s amples.