Smartphone-assisted off─on photometric determination of phosphate ion based on target-promoted peroxidase-mimetic activity of porous CexZr1-xO2 (x≥0.5) nanocomposites

Xin Li; Bangxiang Liu; Zhi Hu; Peng Liu; Kun Ye; Jianming Pan; Xiangheng Niu

doi:10.1016/j.envres.2020.109921

Smartphone-assisted off─on photometric determination of phosphate ion based on target-promoted peroxidase-mimetic activity of porous Ce_xZr_1-xO₂ (x≥0.5) nanocomposites

Environ Res. 2020 Oct:189:109921. doi: 10.1016/j.envres.2020.109921. Epub 2020 Jul 12.

Authors

Xin Li¹, Bangxiang Liu², Zhi Hu², Peng Liu², Kun Ye², Jianming Pan², Xiangheng Niu³

Affiliations

¹ Institute of Green Chemistry and Chemical Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, PR China; School of Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
² Institute of Green Chemistry and Chemical Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
³ Institute of Green Chemistry and Chemical Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, PR China. Electronic address: niuxiangheng@ujs.edu.cn.

PMID: 32678743
DOI: 10.1016/j.envres.2020.109921

Abstract

Given the level of phosphate ion (Pi) is a significant indicator of eutrophication in environmental waters, it becomes quite important to develop efficient methods for its monitoring. In this research, we developed a smartphone-assisted off─on photometric approach for Pi analysis based on the analyte-promoted peroxidase-mimicking catalytic activity of porous Ce_xZr_1-xO₂ (x ≥ 0.5) nanocomposites. The Ce⁴⁺/Ce³⁺ redox pair in Ce_xZr_1-xO₂ endowed it with certain activity to catalyze the 3,3',5,5'-tetramethylbenzidine (TMB) color reaction with the participation of H₂O₂, and both the existing Zr⁴⁺ and Ce⁴⁺ species enabled the nanozyme to specifically recognize Pi. It was observed that the bonded Pi could greatly promote the peroxidase-like activity of the Ce_xZr_1-xO₂ nanocomposite towards positively charged TMB. According to the new finding, high-performance sensing of Pi with wide detection range, high sensitivity and good selectivity was realized, giving a detection limit down to 0.09 μM. Further, a 3D-printed smartphone-based signal reading system was designed and coupled with the sensing method, enabling the rapid, convenient, in-field and instrument-free analysis of Pi for environmental monitoring.

Keywords: Ceria-zirconia composite; Colorimetric detection; Nanozyme; Peroxidase-like activity; Pi; Smartphone.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Colorimetry*
Hydrogen Peroxide
Nanocomposites*
Oxidation-Reduction
Peroxidase
Peroxidases
Phosphates
Porosity
Smartphone

Substances

Phosphates
Hydrogen Peroxide
Peroxidases
Peroxidase