A CO₂optical sensor based on self-assembled metal–organic framework nanoparticles

Abstract

An optical CO2sensor is fabricated by integration of a self-assembled, transparent film of zeolitic imidazolate framework-8 (ZIF-8) nanoparticles onto bimodal optical waveguides. This sensor shows a limit of detection (LOD) of 774 ppm CO2, is robust, fast and reusable, and can be stored under humid conditions with no loss in performance.

Colloidal metal–organic framework particles: the pioneering case of ZIF-8

“…Various recent examples point to the future of the field (Fig. 9), including formation of self-assembled transparent films/monoliths using ultra-small colloidal ZIF-8 particles for use, for example, in shaping monoliths and in optical sensing; 18,63 self-assembly of colloidal ZIF-8 particles of highly monodisperse size and shape into ordered supercrystals for use in photonics, sensing and other domains; 7,15,64 formation of functionalized carbons with interesting electrochemical properties using complex colloidal ZIF-8 composites; 38,58 and design of highly complex single-particle ZIF-8 composites for use in catalysis and biomedicine. 62, _ENREF_64 65 These are but a We believe that recent progress in the synthesis and applications of colloidal ZIF-8 has set the stage for further development of colloidal MOFs.…”

“…In 2018, Chocarro-Ruiz et al proved that using a shorter reaction time yields smaller ZIF-8 particles. 18 They reduced the average size of monodisperse ZIF-8 nanocrystals down to 32 ± 5 nm by following a conventional synthetic procedure (Zn(NO3)2/2mim/MeOH= 1:8:1000, room temperature) but shortening the total reaction time to 7 minutes. After initial homogenization of Please do not adjust margins Please do not adjust margins the starting solutions, they left the mixture undisturbed.…”

Metal–Organic Framework Thin Films: Fabrication, Modification, and Patterning

“…In contrast to other porous materials, MOFs also possess designable structures that can be engineered with tailored pores for selective adsorption of specific gases [1]. Moreover, MOFs show outstanding features as in structural flexibility, thermal and chemical stability, etc., which grant MOFs great potential in numerous applications, such as gas storage and separation [2][3][4][5], liquid purification [6][7][8][9], catalysis [10][11][12][13], gas/chemical sensing [14][15][16][17][18], and energy production [19][20][21][22]. Other than direct applications, MOFs have also been used as precursors/templates for the production of inorganic functional materials with unique designability [23].…”

Advancing Metal‐Organic Frameworks toward Smart Sensing: Enhanced Fluorescence by a Photonic Metal‐Organic Framework for Organic Vapor Sensing

“…Recently, various groups have fabricated template‐free MOF colloidal crystals films and directly applied their iridescence and optical absorbance to chemical sensing. [ 25–29 ] Until now, there are no reports on the luminescent signal amplification of fluorophores by periodic structures of MOFs, except for a study on dye fluorescent enhancement by a SiO 2 /MOF‐5 photonic composite structure. However, the composite material suffers from a reduced surface area compared to pure MOF.…”