Enhanced Long-Term Antifouling Ability and Enrichment Effect of a Vertically Ordered Mesoporous Silica Film via Covalent Linkage of Chondroitin Sulfate for In Situ Detection of Cu2+ in Real Environmental Samples

The design and construction of antifouling sensing interfaces have been widely concerned due to the matrix effect of the complex environment and nonspecific adsorption at the electrode interface. However, it is challenging to ensure the long-term stability of an antifouling sensing interface during real sample detection. Herein, an interface construction strategy based on covalent bonds is proposed for striking enhancement of the long-term antifouling ability of a sensing interface based on a vertically ordered mesoporous silica film (VMSF) and a biobased antifouling material─chondroitin sulfate (CS). The covalent linkage of VMSF with CS (named VMSF-g-CS/GCE) could strengthen the long-term hydrophilicity and biocompatibility of VMSF/GCE. As expected, the VMSF-g-CS/GCE exhibited excellent long-term antifouling performances, which is a promising candidate sensing platform to be applied to long-term monitoring. Alternatively, the VMSF-g-CS/GCE exhibits a better enrichment effect to Cu2+ than VMSF/GCE and VMSF-CS/GCE (without covalent bonds). Therefore, VMSF-g-CS/GCE exhibited a current response toward Cu2+ within the scope of 0.1–0.8 μM, with a limit of detection (LOD) of 20.58 nM. The proposed design strategy offers an idea for the precise regulation of antifouling sensing surfaces, and the resulting high-performance sensing platform is attractive for in situ detection of Cu2+.