A screen-printed biosensor using pyruvate oxidase for rapid determination of phosphate in synthetic wastewater.
A screen-printed phosphate biosensor based on immobilized pyruvate oxidase (PyOD, E.C. 1.2.3.3) has been developed for monitoring phosphate concentrations in a sequencing batch reactor (SBR) system. The enzyme was immobilized by a nafion matrix and covered a poly(carbamoyl) sulfonate (PCS) hydrogel on a screen-printed electrode. PyOD consumes phosphate in the presence of pyruvate and oxygen and generates hydrogen peroxide (H2O2), carbon dioxide and acetylphosphate. The electroactive H2O2, monitored at +420 mV vs Ag/AgCl, is generated in proportion to the concentration of phosphate. The sensor has a fast response time (2 s) and a short recovery period (2 min). The time required for one measurement using this phosphate biosensor was 4 min, which was faster than the time required using a commercial phosphate testing kit (10 min). The sensor has a linear range from 7.5 microM to 625 microM phosphate with a detection limit of 3.6 microM. There was good agreement (R2=0.9848) between the commercial phosphate testing kit and the phosphate sensor in measurements of synthetic wastewater in a SBR system. This sensor maintained a high working stability (>85%) after 12 h of operation and involved a simple operation procedure. It therefore serves as a useful tool for rapid and accurate phosphate measurements in the SBR system and probably for process control.
Sino-German Nano-Analytical Lab (SiGNAL), Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. chroger@ust.hk
Roger C H
RC
Kwan
H F
HF
Leung
Phoebe Y T
PY
Hon
J P
JP
Barford
R
R
Renneberg
D019149:Bioreactors; D015374:Biosensing Techniques; D004800:Enzymes, Immobilized; D010710:Phosphates / Q000032:analysis*; D011771:Pyruvate Oxidase; D012722:Sewage / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis
D004800:Enzymes, Immobilized; D010710:Phosphates; D012722:Sewage; D014874:Water Pollutants, Chemical; D011771:Pyruvate Oxidase