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

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.