Plasmonic sensors in multi-analyte environment: Rate constants and transient analysis

Abstract

This paper investigates multicomponent gas adsorption at the active surface of plasmonic chemical sensors and shows that there are situations where transients in a single sensor element can be used for simultaneous detection of different gases in multicomponent mixtures. A general master equation set is provided, describing multicomponent adsorption. Analytical expressions for sorption rates are derived and high-accuracy simplified models are proposed. Expressions for adsorption rate constants and rates and for number of binding sites are proposed. The derived analytical model takes into account the adsorbate molecule size, distribution of binding sites as determined by the crystallographic structure of the sensor surface and multi-site adsorption. The model allows for the calculation and optimization of deterministic behavior of the system. It is shown that trace amounts of target gas species can be made detectable by adding controlled amounts of known carrier gas. Besides being applicable in plasmonic sensor design and optimization, the obtained results may be of importance in situations where fast and low-cost detection of trace amounts of gases is needed, including natural gas leakage in residential heating, radon outgassing in dwellings, environmental protection, homeland defense and hazardous materials management, greenhouse footprint investigations, etc. HIGHLIGHTS  general equation set for multicomponent monolayer gas adsorption is derived  analytical model of adsorption takes into account adsorbate molecule size  adsorption rate constants are modeled using chemical software and data mining  simultaneous plasmonic sensing of several gas species in mixture is considered

Realization of Fractal-Inspired Thermoresponsive Quasi-3D Plasmonic Metasurfaces with EOT-Like Transmission for Volumetric and Multispectral Detection in the Mid-IR Region

“…The proposed fractal architectures can be treated as a novel platform for multiple analyte SEIRA, which is a powerful biomedical analysis tool. 50,51 The quasi-3D nanochannels of the nanostructures in which volumetric enhancement of the electric field occurs can be potentially useful for such applications. Herein, because of the hybrid nature of the devices, we consider both purely plasmonic modes (D4′ and D1″) and the hybridized features (between D3′ and D4′ and between D3″ and D4″) and demonstrate their volumetric refractive index sensitivity in the reflection mode.…”

Monolayer Gas Adsorption on Graphene-Based Materials: Surface Density of Adsorption Sites and Adsorption Capacity

“…In the process of adsorption, different spacial orientations cause different numbers of occupied adsorption centers of the same gas species and in some cases may bond differently with different desorption energies. Consequently, the number of adsorption sites on the graphene surface cannot be modeled solely by using the information on the crystallographic structure of the surface as in the case of adsorption of small molecules on solid surfaces and it can not be modeled solely by using the information on the molecular structure and orientation, which is possible for modeling adsorption on homogeneous surfaces [13].…”

“…Analytical models of the rate constants for adsorption and desorption, based on the ideal gas theory, applicable to the gas adsorption on a homogeneous crystallographic surface, are presented in [13]. Apart from pressure, temperature, molar mass of the gas and its affinity towards the surface, the surface density of the adsorption sites on the surface and the desorption energy are needed for the calculation of the rate constants.…”

Quantitative Measures of Reliability and Sensitivity of Nanoparticle-Based Sensors in Detecting Volatile Organic Compounds

“…24−27 In one theoretical model, the equation of the rate reaction for a single analyte could successfully be extended to account for an n VOCs mixture, assuming a single adsorbate molecule on one binding site. 26 Another theoretical model for evaluation of the AD noise in the microfluidic structure with biosensors operating in an n analytes environment could account for small fluctuations as a random process in the detection signal around the equilibrium. 27 To improve the GNP sensors and to enable quantitative measures for their reliability and sensitivity, a better and more comprehensive understanding of AD parameters is required.…”

“…Our results show that the AD parameters give quantitative measures of sensors’ reliability and sensitivity and can be extended for an n VOCs mixture, assuming a single VOC molecule per binding site. 26…”