Molecularly Imprinted Polymer Real-Time Gas Sensor for Ambient Methanol Vapor Analysis Developed Using Principles of Sustainable Chemistry

Abstract

A molecularly imprinted polymer-based composite has been fabricated for gas-phase sensing using principles of green chemistry. Methanol vapor was chosen as a target, being simultaneously a common industrial hazard and a relatively safe analogue for volatile pollutants. The sensor was therefore produced both from environmentally sustainable sources and for environmentally useful purposes. The described methanol sensor is effective at room temperature and in laboratory air, being the first demonstration of such a technology using molecularly imprinted polymers. The sensor is therefore a sustainable progression in purpose and application, negating the previous requirement that analytes be heated before they can be detected. The MIP−graphite composite showed selectivity for methanol vapor over common interferents, including other alcohols. The limit of detection was found to be 126 μmol dm −3 , and a consistent response was demonstrated up to 3.3 mmol dm −3 . Studies also demonstrated that the sensor could reproduce a response in proportion to methanol vapor concentration after several months of storage under ambient conditions. Molecularly imprinted polymer gas sensors are therefore shown to be an effective basis for selective and sustainable pollutant monitoring.

Molecularly imprinted polymer nanoparticle-carbon nanotube composite electrochemical gas sensor for highly selective and sensitive detection of methanol vapour

“…Catalysis is implied by the electron transfer to the electrode observed when the nanoMIPs are present, but the lack of any electron transfer in their absence at the observed potential (−3.0 V to 3.0 V). Previous studies showed no reaction of the bare electrode with methanol vapour in the range −5.0 to 5.0 V, 23 suggesting that oxidation on the bare electrode occurs either at a very high potential or within this range at a negligible rate.…”

“…Scanning electron microscopy images of the isolated nanoMIPs were presented in a previous publication, where they were found to have a diameter in the range of 200 and 600 nm. 23 Non-imprinted 'blank' equivalents of the CNT-nanoMIP sensors were prepared by applying this same protocol with the exclusion of the methanol template. A series of sensors were prepared and the most successful, in response to 1 mM methanol vapour, further studied at 1.5 mM and 2 mM.…”

“…Uncoated screen-printed electrodes have been previously studied and found to give no response to the gases used in this study. 23 A scheme of the experimental protocol is given in Fig. 2.…”

“…Recent publications have demonstrated the potential for MIP-based sensors in the ambient detection of methanol vapour, 23,24 but the selectivity is relatively low and the sensitivity is insufficient for regulatory standards. [25][26][27] Herein we describe a nanoMIP electrochemical sensor modified with multiwalled carbon nanotubes (CNTs) for the selective and sensitive detection of methanol vapour.…”

Construction of Sustainable Biomass Bubble Propulsion Micromotor and Selective Recognition/Separation of Shikimic Acid with Open 3D Target Imprinting Cavity

“…Once the target is extracted from the network, a vacancy that is identical to the size, steric configuration, and functionality of the target leaves; thus, MIPs possess the specific recognition and high affinity capacity toward the target. MIPs have emerged as a promising tool for the separation and purification of target molecules from complex matrices. , Denizli’s group prepared Concanavalin A imprinted porous cryogels for the purification of Concanavalin A from jack bean source . The binding selectivity of imprinted cryogels is evidently superior to the nonimprinted samples.…”