ZrO2/CeO2/polyacrylic acid nanocomposites with alkaline phosphatase-like activity for sensing

Schematic illustration of the ZrO2/CeO2/ polyacrylic acid nanocomposites as an alkaline phosphatase mimetic enzyme for the detection of methyl parathion. [Display omitted] •ZrO2/CeO2/polyacrylic acid nanocomposites showed excellent adaptability at a wide temperature and pH range.•The developed colorimetric detection system had a wide linear range and a low detection limit.•The detection system had high specificity and stability and was successfully applied for the in corn samples. In the present work, we synthesized ZrO2/CeO2/polyacrylic acid (PAA) nanocomposites (nanozyme) with phosphatase-like activity. ZrO2 evenly distributed in CeO2 nanorods considered as lewis acids to enhance the phosphatase-like activity of CeO2 nanorods. Furthermore, PAA was used to coat ZrO2/CeO2/ nanorods and improve the dispersion, stability and robustness. The ZrO2/CeO2/PAA nanocomposites had 100% enhanced phosphatase-like activity compared with CeO2 nanorods and excellent adaptability in a wide pH range from 4.0 to 12.0. ZrO2/CeO2/PAA nanocomposites could hydrolyze methyl parathion (MP) to p-nitrophenol (p-NP) with bright yellow color for colorimetric detection. The developed colorimetric detection system showed a linear response from 7.60 × 10-11-7.60 × 10-8 M with a detection limit of 0.021 nM and was successfully applied for the determination of MP in corn samples.