Silica-Nanochannel-Based Interferometric Sensor for Selective Detection of Polar and Aromatic Volatile Organic Compounds

Abstract

Public awareness of the toxicity of volatile organic compounds (VOCs) has led to increased requirements for direct measurement of these substances. This work reports the sensitive detection of VOCs at the ppb level by an interferometric sensor based on the multilayer silica-nanochannel membrane (MSNM). The MSNM is fabricated by layer-by-layer stacking of a free-standing ultrathin SNM composed of regularly ordered channels with an ultrasmall diameter of about 2.3 nm and an ultrahigh density of about 4 × 10 cm. Light reflected from parallel interfaces of the MSNM gives rise to the interferometric pattern with constructive and destructive fringes. The adsorption of VOCs to a highly porous MSNM varies the refractive index of the MSNM, resulting in the shift of the reflectometric interference spectrum (RIS) and thus yielding highly sensitive responses with a limit of detection (LOD) at the ppb level. Moreover, the sensor selectively responds to polar ethanol and acetone, as well as aromatic benzene, toluene, and chlorobenzene, but is insensitive to nonpolar ethane or hexane. The selectivity most likely arises from hydrogen bonding and dipole interaction of VOCs with silica surface.

Biomimetic stimuli‐responsive nanochannels and their applications

“…Similar to the biological nanochannels in living systems, the biomimetic stimuli‐responsive nanochannels also show some characteristics such as ion selectivity, ion rectification and ion gating, which can be used in many fields including biosensors, and drug delivery .…”

“…(A) Supersandwich structure‐based nanopore sensors for detecting ATP and DNA; (B) Schematic description of the hour‐glass shaped sensor for glucose detection; (C)Scheme description of a novel nanodevice by decorating continuous Au nanoparticles with three geometric dimensions on the inner surface of channels in AAO membranes; (D) Sketch map of detecting miR‐204 and miR‐210 sensor based on solid nanopores; (E) Schematic illustration of device for detecting retinol and AA in fruit juices based on mesochannels on the electrode surface and DPVs of CM@SMA/ITO and SMA/ITO electrodes in untreated commercial orange juice before and after the addition of 2 mM AA; (F) Schematic illustration of volatile organic compound detection by multilayer silica‐nanochannel membrane‐based interferometry. (a) Reproduced with permission from , copyright 2013, Wiley‐VCH; (b) Reproduced with permission from , copyright 2014, American Chemical Society; (c) Reproduced with permission from , copyright 2015, Wiley‐VCH; (d) Reproduced with permission from , copyright 2017, American Chemical Society; (e) Reproduced with permission from , copyright 2016, American Chemical Society; (f) Reproduced with permission from , copyright 2018, American Chemical Society.…”

“…Most recently, Su group reported the sensitive detection of volatile organic compounds by an interferometric sensor based on the multilayer silica‐nanochannel membrane (Fig. F) . This membrane is fabricated by layer‐by‐layer stacking of a free‐standing ultrathin silica‐nanochannel membrane composed of regularly ordered channels with diameter of about 2.3 nm.…”

“…Inspired by biological ion channels, various artificial smart nanochannels with different functions have emerged as a fascinating research field in recent years. Compared with the fragile biological counterparts, the artificial smart nanochannels have some similarities either the structure (size and shape) or the function characteristics, but beyond that, also possessing distinct advantages, such as excellent mechanical robustness, tunable surface properties, good durability, reproducible, which make them useful for many potential applications, ranging from biosensors to drug delivery systems .…”

Reversible Vapochromic Luminescence Accompanied by Planar Half‐Chair Conformational Change of a Propeller‐Shaped Boron β‐Diketiminate Complex

“…PMs which exhibit luminescent chromism in response to exposure to vapors of volatile organic compounds (VOCs), especially, are attractive materials for detecting a small amount of leakage of toxic or explosive gases and for security ink. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] However, these compounds possess potential instability toward the air, moisture, and/or other harsh chemical conditions, and therefore a growing number of studies have recently reported chemically and physically stable PMs. [32,33] Nonporous molecular crystals (NMCs), on the other hand, have no such functional voids in their packing patterns because of the absence of the polymeric or supramolecular structures derived from continuous valence, coordination, or hydrogen bonds.…”