Molecular Imprinting in Sol–Gel Materials: A Focus on the Interplay between Matrix Design and Structural Properties

Abstract

Molecular imprinting in sol-gel matrices has emerged as a versatile strategy for creating functional materials with selective recognition sites that mimic biological receptors. By incorporating a suitable molecular template during the hydrolysis-condensation of metal alkoxides or hybrid precursors and removing it after gelation, the resulting network becomes "molecularly imprinted," generating cavities that are geometrically, chemically, and energetically complementary to the template. Although conceptually simple, imprinting in the highly dynamic, kinetically complex sol-gel process is far from trivial. The performance of imprinted gels reflects a delicate interplay among reaction kinetics, structural evolution, solvent effects, template-precursor interactions, and post-synthesis processing. This review provides a critical analysis of sol-gel molecular imprinting, examining structure-property relationships, thermodynamic and kinetic constraints, matrix design strategies, and application-driven perspectives to define the current state and future directions of the field.