Silver Ion Polyelectrolyte Container as a Sensitive Quartz Crystal Microbalance Gas Detector

Abstract

A polyelectrolyte film containing metastable silver ions was applied as a quartz crystal microbalance (QCM) gas detector. The polyelectrolyte film was obtained by immersing a polyelectrolyte with numerous amine groups in a metal ion solution. The QCM detector with silver ions responded to a very low methylmercaptan gas concentration (20 ppb) but did not respond to ammonia, volatile amines, aromatic compounds, or alcohols. The response speed of the QCM detector increased gradually with increasing methylmercaptan concentrations. The highly sensitive and selective response is promoted by a ligand substitution reaction caused by the formation of coordinative bonds between a metastable silver ion and amine groups in the polyelectrolyte film. To the best of our knowledge, this system has the highest sensitivity among reported QCM gas detectors. Such high-sensitivity among reported QCM gas detectors. Such high-sensitivity gas detectors for volatile sulfur compounds have wide ranging applications in areas such as volcanic eruption prediction, food inspection, environmental analysis, and medical diagnostics.

Weak Polyelectrolytes as Nanoarchitectonic Design Tools for Functional Materials: A Review of Recent Achievements

“…Conversely, not only the ionic strength but also the nature and valence of the salt used as the post-assembly stimulus were found to modulate the properties of weak polyelectrolyte multilayers: exposing a PAH/PAA multilayer film to various concentrations and type of metal ions enabled changing their pore sizes from 54 nm to 1.63 μm. This behavior was ascribed to phase separation in the film induced by metal-ion coordination with PAH [ 112 ], and was used to trap silver ions in the film to selectively detect methylmercaptan gas concentrations as low as 20 ppb [ 113 ].…”

Integrated Nanophotonic Waveguide-Based Devices for IR and Raman Gas Spectroscopy

“…Alternatively, reactive centers with high selectivity toward specific reactants such as platinum nanoparticles have been described [99]. Although, still, no reports can be found on specific cladding for integrated infrared spectroscopy for the pre-concentration of gases such as carbon dioxide, methane, or acetylene, some examples can be found in works on ATR crystal [197], quartz crystal microbalance [198,199], and refractive index gas sensors [96,99,200].…”

Antifouling hydrogel film based on a sandwich array for salivary glucose monitoring

“…[19][20][21] Quartz crystal microbalance (QCM) has been developed for salivary glucose monitoring and has become successful for the online detection of many other target molecules, such as protein, bacteria and nucleic acids because of its low cost, the ability of real-time detection and label-free property. [22][23][24][25][26] For example, in our recent work, we have reported a glucose-sensitive QCM sensor based on interpenetrating polymer network (IPN) hydrogel lm, which has realized the typical salivary glucose monitoring (0-50 mg L À1 ) in diluted saliva. However, the hydrogel lm cannot provide robust resistance to protein contaminants in saliva, and the total content of proteins in saliva is about 71-2232 mg L À1 , which is 1.9-4133 fold higher than the typical glucose level (0.54-37.8 mg L À1 ).…”