3D models of molecularly imprinted polymer nanofilms coupled to interdigitated microelectrodes: A physical performance analysis

• Published in: Sensors and actuators. A. Physical. 2024-05, Vol.370, p.115251, Article 115251
• Main Authors: Jiménez-Rivas, Diana, Cuevas-Muñiz, F.M., Méndez-Aguilar, Emilia M., Herrera-Celis, José
• Format: Article
• Language: English
• Subjects: COMSOL multiphysics; Glyphosate; Impedimetric sensor; Interdigitated microelectrodes; Molecularly imprinted polymer
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2024.115251

This work presents the development of three 3D models in COMSOL Multiphysics® to study the performance of sensing platforms based on molecularly imprinted polymer (MIP) nanofilms (∼50 nm thick) deposited on interdigitated microelectrodes (IDMEs). Polypyrrole and glyphosate were selected as the MIP matrix and the target analyte, respectively. A real prototype was tested to adjust the morphological and electrical parameters of the MIP nanofilm. The prototype and the 3D models were evaluated using electrical impedance spectroscopy. Considering the fill factor concept, the percentage relative change in impedance (Δ|Z|Rel) as the target analyte is attached to the MIP nanofilm was estimated. Three zones appear in the impedance spectra, but only two are related to glyphosate incorporation. In both zones, the impedance increases as the glyphosate fills the MIP nanofilm. The glyphosate incorporation modifies the surface area and affects the electrical properties of the MIP nanofilm seen as a whole. The models reproduce the sensing zones and allow studying the predominant factors in each zone and estimating the performance in terms of Δ|Z|Rel. A Δ|Z|Rel as high as 142% was obtained at 100 mHz under saturation, which agrees with experimental results reported with a similar arrangement. These 3D models, as well as the simulation strategy, are useful in interpreting results related to MIP/IDME-based sensors, which are versatile and easy-to-use devices. [Display omitted] •3D models built in COMSOL allow simulating layers as thin as 2 nm despite the high aspect ratio compared to the other layers.•Impedance spectra correlation with changes in the morphological and electrical properties of the ppy-MIP nanofilms.•3D models manage to reproduce and explain previously published experimental results.•High percentage relative changes in impedance are achieved at low fill factors, which is associated with low LODs.