Quantitative characterization of colloidal assembly of graphene oxide-silver nanoparticle hybrids using aerosol differential mobility-coupled mass analyses

Abstract

In this work, we develop an aerosol-based, time-resolved ion mobility-coupled mass characterization method to investigate colloidal assembly of graphene oxide (GO)-silver nanoparticle (AgNP) hybrid nanostructure on a quantitative basis. Transmission electron microscopy (TEM) and zeta potential (ZP) analysis were used to provide visual information and elemental-based particle size distributions, respectively. Results clearly show a successful controlled assembly of GO-AgNP by electrostatic-directed heterogeneous aggregation between GO and bovine serum albumin (BSA)-functionalized AgNP under an acidic environment. Additionally, physical size, mass, and conformation (i.e., number of AgNP per nanohybrid) of GO-AgNP were shown to be proportional to the number concentration ratio of AgNP to GO (R) and the selected electrical mobility diameter. An analysis of colloidal stability of GO-AgNP indicates that the stability increased with its absolute ZP, which was dependent on R and environmental pH. The work presented here provides a proof of concept for systematically synthesizing hybrid colloidal nanomaterials through the tuning of surface chemistry in aqueous phase with the ability in quantitative characterization. Graphical Abstract Colloidal assembly of graphene oxide-silver nanoparticle hybrids characterized by aerosol differential mobility-coupled mass analyses.

Aerosol-Based Self-Assembly of a Ag–ZnO Hybrid Nanoparticle Cluster with Mechanistic Understanding for Enhanced Photocatalysis

“…In this work, we demonstrate a facile gas-phase synthetic method to fabricate noble metal–ZnO hybrid nanostructure. Here, silver NP (AgNP) is used as the representative noble metal NP because of its substantial interest of the metal-enhanced optical properties generated by surface plasmon resonance (SPR) of AgNPs. ,,,,,− Using an evaporation-induced self-assembly (EISA), , a stable, isotropic aqueous solution containing ZnO and Ag precursors is nebulized as droplets in a carrier air. The fast evaporation of droplets triggers self-assembly to create aerosol particles of dried precursor crystallites, and then the dried precursor crystallites converted to Ag–ZnO hybrid nanostructure via direct gas-phase calcination. ,− In comparison with the traditional synthetic approaches reported previously, ,,,,,, the gas-phase synthetic method demonstrates the following superior advantages: (1) a continuous synthetic process with an ability in the tuning of chemical composition and oxidation state ,− and (2) avoiding the issues related to the restrictions arising from solution-based chemistry used for creating homogenous distribution of active component in the hybrid nanostructure (e.g., restriction in the properties of solvent and addition of surfactants during the synthesis). ,− …”

Zirconium-Based Metal–Organic Framework Nanocarrier for the Controlled Release of Ibuprofen

“…2,3,18,20,21 Herein we establish a new, potent measurement methodology to study the MOF-based drug-delivery platform using a gasphase electrophoretic approach, electrospray-differential mobility analysis coupled with aerosol particle mass analysis (ES-DMA/APM). 13,22 A schematic diagram of the use of ES-DMA/ APM to characterize molecular drug-loaded MOF particles is shown in Scheme 1a. First, a stably dispersed aqueous MOF colloid is aerosolized via an electrospray aerosol generator (model 3480, TSI Inc., Shoreview, MN), followed by an immediate charge neutralization using a Po A number-based mobility size distribution of the MOF particles is obtained by scanning the voltage applied to DMA from 80 V to 10 kV.…”

“…13,23,24 The aerosol particle mass distribution is obtained by scanning a direct circuit electric field with an applied voltage to APM ranging from 90 to 380 V at a fixed rotation speed of 10000 rpm. 22,25 The number of particles with specific d p,m and m p values are both recorded using a butanol-based condensation particle counter (model 3775, TSI Inc., Shoreview, MN).…”

“…Subsequently, MOF aerosols with specific mobility diameters ( d p,m ) are transported to an aerosol particle mass analyzer (model 3601, Kanomax USA, Andover, NJ) to analyze their aerosol mass ( m p ). A number-based mobility size distribution of the MOF particles is obtained by scanning the voltage applied to DMA from 80 V to 10 kV. ,, The aerosol particle mass distribution is obtained by scanning a direct circuit electric field with an applied voltage to APM ranging from 90 to 380 V at a fixed rotation speed of 10000 rpm. , The number of particles with specific d p,m and m p values are both recorded using a butanol-based condensation particle counter (model 3775, TSI Inc., Shoreview, MN).…”

“…In comparison to the separation-and-analysis methods, the ES-DMA/APM approach offers direct measurement on a particle with a high resolution (i.e., up to 0.3 nm in d p,m and ≈4% to the measured m p ), which has shown the promise of minimizing interference from the unbound molecules in solution. ,, Moreover, the ES-DMA/APM method requires only a very small amount of sample (<0.01 mg), and the detection limit reaches 3 nm in d p.m and 1 ag in m p . ,,− …”