Poly(ionic liquid)-regulated green one-pot synthesis of Au@Pt porous nanospheres for the smart detection of acid phosphatase and organophosphorus inhibitor

Here, a green poly(ionic liquid)-regulated one-pot method is developed for the synthesis of Au@Pt core-shell nanospheres (PNSs) under mild reaction conditions in water. It is found that the poly(ionic liquid) poly[1-methyl-3-butyl (3-hydroxy) imidazole] chloride (PIL-Cl) is very vital to guide the construction of Au@Pt PNSs. The as-obtained Au@Pt-1 PNSs have perfect spherical outlines, porous core-shell structures and large specific surface area by which they exhibit excellent peroxidase-like activity in acidic media and can be used to develop a simple and reliable colorimetric sensing platform. It is shown that the colorimetric sensing platform constructed with Au@Pt-1 PNSs nanozyme can effectively evaluate ACP activity, achieving a wide linear detection range of 0.1-3.0 U/L and having a low limit of detection (LOD) of 0.047 U/L (S/N = 3). Based on the cascade reaction, the Au@Pt-1 PNSs nanozyme and ACP are integrated to develop a biosensor, which can detect organophosphate inhibitor of malathion with a wide linear detection range of 5-80 nM and low LOD of 1.96 nM (S/N = 3). More importantly, this detection method is also practically applied to detect both ACP activity in fetal bovine serum and malathion concentration in cucumber juice with satisfied results. This work presents a simple and green feature for the synthesis of nanozyme with high performance and establishes a biosensing platform based on Au@Pt-1 PNSs nanozyme to effectively monitor the ACP activity and the concentration of its organophosphate inhibitor malathion with high sensitivity, anti-interference capability and good recovery capability.