Polypyrrole-based potentiometric phosphate biosensor

Trace-Level Sensing of Phosphate for Natural Soils by a Nano-Screen-Printed Electrode

Phosphate as one of the most essential components of living systems, robust analytical techniques available for phosphate sensing in natural waters and soils are essential for monitoring and predicting water quality and agronomic evaluation of phosphate. Using cyclic voltammetry, a point-of-use electrochemical sensor zirconium dioxide/zinc oxide/multiple-wall carbon nanotubes/ammonium molybdate tetrahydrate/screen printed electrode (ZrO₂/ZnO/MWCNTs/AMT/SPE) was applied to explore the electro-redox reaction of phosphomolybdate complexes on the surface of electrode, which produced a quantitative electrochemical response of phosphate anions. The modification of the electrode surface with ZrO₂/ZnO/MWCNTs nanocomposites is able to generate the electroactive species via chemical reaction between molybdenum (Mo(VI)) and the targeted phosphate anions, leading to a sensitive detection technique for trace phosphate with a lower detection limit (LOD = 2.0 × 10^-8 mol L^-1), higher reproducibility, anti-interference, and precision in different soil sources. This system will be of great potential to advance the trace-level understanding of phosphate especially in field environmental analysis.

Progress and recent advances in fabrication and utilization of hypoxanthine biosensors for meat and fish quality assessment: a review

This review provides an update on the research conducted on the fabrication and utilization of hypoxanthine (Hx) biosensors published over the past four decades. In particular, the review focuses on progress made in the development and use of Hx biosensors for the assessment of fish and meat quality which has dominated research in this area. The various fish and meat freshness indexes that have been proposed over this period are highlighted. Furthermore, recent developments and future advances in the use of screen-printed electrodes and nanomaterials for achieving improved performances for the reliable determination of Hx in fish and meat are discussed.