Metal–Organic Framework-Based Sensors for Environmental Contaminant Sensing

Abstract

Increasing demand for timely and accurate environmental pollution monitoring and control requires new sensing techniques with outstanding performance, i.e., high sensitivity, high selectivity, and reliability. Metal–organic frameworks (MOFs), also known as porous coordination polymers, are a fascinating class of highly ordered crystalline coordination polymers formed by the coordination of metal ions/clusters and organic bridging linkers/ligands. Owing to their unique structures and properties, i.e., high surface area, tailorable pore size, high density of active sites, and high catalytic activity, various MOF-based sensing platforms have been reported for environmental contaminant detection including anions, heavy metal ions, organic compounds, and gases. In this review, recent progress in MOF-based environmental sensors is introduced with a focus on optical, electrochemical, and field-effect transistor sensors. The sensors have shown unique and promising performance in water and gas contaminant sensing. Moreover, by incorporation with other functional materials, MOF-based composites can greatly improve the sensor performance. The current limitations and future directions of MOF-based sensors are also discussed.

Hydrogen production and photocatalytic activity of g‐C3N4/Co‐MOF (ZIF‐67) nanocomposite under visible light irradiation

“…Metal–organic frameworks (MOF) are a novel class of porous material, which are constructed from metal ions (M + )/clusters linked by organic ligands to form 1D, 2D, or 3D structures . These materials exhibit excellent, unique properties such as high surface area, tailorable chemistry, wide range of pore size, structural diversity and are easily functionalized, these properties make MOF an advanced material for various applications such as for gas storage, in drug delivery catalyst and so on. MOF are similar to metal oxide semiconductors in that they can also be photo‐excited to generate e − /h + pairs .…”

Fluorescent “Turn‐on” Sensing Based on Metal–Organic Frameworks (MOFs)

“…Thus, a turn‐on response which could be involved in selective sensing of such compounds is always desirable due to its higher distinguishability. Recently, some groups have come up with strategies to overcome the limitation of turn‐off sensing for explosive and related compounds …”

“…Thus,aturn-onr esponse whichc ould be involved in selectives ensing of such compounds is always desirable due to its higher distinguishability.R ecently,s omeg roups have come up with strategies to overcome the limitation of turn-off sensing for explosive and related compounds. [44] Wang and his group members reported two (4,4'-((Z,Z)-1,4diphenylbuta-1,3-diene-1,4-diyl)dibenzoic acid (TABD-COOH) based MOFs built from Ni 2 + and Co 2 + .S ince these metal ions had incomplete sub-shells, the resultingM OFs were non-luminescent with al ow quantum yield. Next, these MOFs were tested for responset owards 5-nitro-2,4-dihydro-3H-1,2,4-triazole-3-one (NTO) which is ah igh energy explosive.…”

MOF@PEDOT Composite Films for Impedimetric Pesticide Sensors

“…[23,24] The use of many MOFs was extensively explored regarding its possible applications in water-based separations and chromatography, [25][26][27][28] provided that selected materials fulfill the crucial requisite of stability toward hydrolysis. [31][32][33][34][35][36][37] Based on the signal transduction possible for many configurations, sensors reported can be described as optical, [38,39] electrochemical, [40][41][42] mechanical, [43] photoelectrochemical, [44][45][46][47] or combined-miscellaneous. [30] The advantageous features of different MOFs have been rapidly applied in the development of sensors.…”

“…[30] The advantageous features of different MOFs have been rapidly applied in the development of sensors. [31][32][33][34][35][36][37] Based on the signal transduction possible for many configurations, sensors reported can be described as optical, [38,39] electrochemical, [40][41][42] mechanical, [43] photoelectrochemical, [44][45][46][47] or combined-miscellaneous. [48] Among MOFs, MIL-101(Cr) is a well-known material robust toward exposure to aqueous environments.…”