Mesoporous materials in sensing: morphology and functionality at the meso-interface

Abstract

Mesoporous materials are finding increasing utility in sensing applications. These applications can benefit from a surface area that may exceed 1,000 m(2) g(-1) and fast diffusion of analytes through a porous structure. This article reviews recent developments in mesoporous materials-based sensing and provides examples of the impact of different surface functionality, pore structure, and macro-morphology in an attempt to illustrate the contribution of these factors to the selectivity and sensitivity of a sensor response. The materials discussed include ordered mesoporous silicates synthesized with surfactants, hard templated ordered mesoporous carbons, and metal oxides with porous textures which have been applied to advantage in various detection schemes. Chemical functionalization of mesoporous materials through silane grafting, co-condensation, and adsorption are also addressed.

Periodic mesoporous organosilicas for advanced applications

“…Organic-inorganic mesoporous silica hybrid materials are attractive for many sensing applications, including heavy metal ions, biomolecules and organic volatiles, because of their stability over a wide range of pH conditions, their inertness in many environments and their transparency in the UV-vis spectrum. 60 Generally, these sensing materials are prepared by the modification of the mesopore surface using alkoxysilanes ((RO) 3 Si-R 0 , R ¼ C 2 H 5 or CH 3 , R 0 ¼ aliphatic with various functional groups (aliphatic or cyclic organic groups including N, S, O, etc.). 60 Studies of sensing and imprinting using PMOs have been reported by several researchers for the removal of organic molecules and metal ions.…”

“…60 Generally, these sensing materials are prepared by the modification of the mesopore surface using alkoxysilanes ((RO) 3 Si-R 0 , R ¼ C 2 H 5 or CH 3 , R 0 ¼ aliphatic with various functional groups (aliphatic or cyclic organic groups including N, S, O, etc.). 60 Studies of sensing and imprinting using PMOs have been reported by several researchers for the removal of organic molecules and metal ions. [61][62][63][64][65][66][67] Riley and co-workers 61 prepared a PMO material with imprinted sites for selective benzene adsorption.…”

Ordered mesoporous carbons as effective sorbents for removal of heavy metal ions

“…Recently, OMCs have found an increasing number of applications in many areas including catalysis [34e36], adsorption [31,37,38], separation [39,40], sensing [41,42], energy storage [43], supercapacitors and electrochemistry [44,45]. Possibility of kilogram-scale synthesis of high-quality OMC [46] coupled with the use of cheap, green precursors [46,47] can make these materials affordable for all the above-mentioned applications.…”

Surface development of molecularly imprinted polymer films to enhance sensing signals

“…Another recent approach allows generation of silicate mesoporous structures with large surface area (up to 1000 m 2 g À1 ) using a surfactant micellar or lamellar phase to fabricate the recognition units of the chemosensor [101]. This large surface area enables high preconcentration of an analyte to enhance detectability.…”