The encapsulation of pyrene-substituted amphiphilic polymers within the interfaces of hydrophobic/hydrophilic core-shell silica gel for the detection of nitroaromatic compounds

Abstract

This study reports the encapsulation of pyrene-substituted amphiphilic polymers within void interfaces of mesoporous core–shell silica gel, specifically engineered for fluorescence-based detection of NACs in both aqueous and organic media. The hydrophobic shell of the silica gel enhances the diffusion of hydrophobic NACs to the silica gel core, where the confined pyrene-substituted amphiphilic polymer acts as a sensor, enabling efficient fluorescence quenching in both aqueous and organic media. The sensor exhibited strong quenching responses, particularly for TNT, with a Stern-Volmer constant of 7.51 × 10⁴ M⁻¹ in dichloromethane and 6.30 × 10⁴ M⁻¹ in water. The sensor also demonstrated excellent reusability, retaining over 95 % of its original fluorescence intensity after four quenching cycles. These results highlight the potential of pyrene-encapsulated core–shell silica gels as highly sensitive, reusable fluorescence sensors for NAC detection, offering promising environmental monitoring and security applications.