Applicability of QCM-D for Quantitative Measurements of Nano- and Microparticle Deposition Kinetics: Theoretical Modeling and Experiments.

Zbigniew Adamczyk,Paulina Żeliszewska,Marta Sadowska

doi:10.1021/acs.analchem.0c03115

Abstract

A new theoretical model is formulated for the quantitative analysis of quartz crystal microbalance (QCM) response for heterogeneous loads consisting of nano- and microparticles. The influence of particle coverage and structure is described using a universal correction function in an ab initio manner. Explicit analytical expressions for the frequency and dissipation shifts are derived for the entire range of particle size under the rigid contact regime. The solvent coupling functions are also calculated to determine the dry coverage using the QCM measurements. These expressions furnish the upper limit of the QCM signal, which can be attained for a sensor providing perfect adhesion of particles. Correction functions accounting for the finite adhesion strength (soft contact regime) are also derived. The theoretical results are confronted with QCM and atomic force microscopy measurements of positively charged polymer particle deposition on silica sensors. The main features of the theoretical model are confirmed, especially the abrupt decrease in the QCM wet mass with the particle coverage and the overtone number. The latter effect is especially pronounced for microparticles under the soft contact regime, where the higher-number overtones produce a negligible QCM signal. These results represent a useful reference data for the interpretation of protein and bioparticles, for example, virus and bacteria attachment processes to various substrates.

Highlights

A new theoretical model is formulated for the quantitative analysis of quartz crystal microbalance (QCM) response for heterogeneous loads consisting of nano- and microparticles
Explicit analytical expressions for the frequency and dissipation shifts are derived in terms of the normalized hydrodynamic boundary layer thickness δ = δ/a under the rigid contact assumption
The influence of particle coverage is described via a universal correction function given by eq 10 derived without adjustable parameters

Summary

Introduction

A new theoretical model is formulated for the quantitative analysis of quartz crystal microbalance (QCM) response for heterogeneous loads consisting of nano- and microparticles. The main features of the theoretical model are confirmed, especially the abrupt decrease in the QCM wet mass with the particle coverage and the overtone number The latter effect is especially pronounced for microparticles under the soft contact regime, where the higher-number overtones produce a negligible QCM signal. Noble metal nanoparticles and their monolayers on solid substrates, play an important role in catalysis, analytical science, and medicine.[6−12] Because of the pronounced biocidal properties, silver nanoparticles are used to modify surfaces of various materials, in particular, fibers and polymers, applied in manifold consumer products such as surgical gowns, dressing bandages, masks,[10,11] and so forth. They serve as analytical sensors in SERS8 and metal-enhanced fluorescence.[9]

Objectives

Methods

Results

Conclusion