Tailored Silica-Based Sensors (SBA-Pr-Ald-MA) for Efficient Detection of Iron (III) Ions: A Comprehensive Theoretical and Experimental Viewpoint

Abstract

The synthesis and characterization of SBA-Pr-Ald-MA as a modified mesoporous silica material made from SBA-15 are presented in this work. Meldrum's acid (MA), 2-chloroquinoline-3-carbaldehyde, and 3-(chloropropyl)-trimethoxysilane were used to functionalize the SBA-15. The detection limit of 7.80 × 10−8 M for SBA-Pr-Ald-MA demonstrated its exceptional selectivity toward Fe3+ ions. Density functional theory (DFT) calculations were conducted using B3LYP/6-311g(d,p)/LANL2DZ to investigate the molecular electrostatic potential (MEP), geometry optimization, molecular orbital analysis, quantum chemical descriptors, and photoinduced electron transfer (PET). Geometry optimization and the MEP diagram verified the mechanism of the interaction obtained from experimental results. PET analysis indicated that the electrons transition to the LUMO of the Pr-Ald-MA + Fe3+ complex, leading to maximum fluorescence quenching efficiency. Future research could explore the sensor's application in real-world environmental monitoring systems and extend its application to detect other hazardous metal ions.