Fractionation and characterization of high aspect ratio gold nanorods using asymmetric-flow field flow fractionation and single particle inductively coupled plasma mass spectrometry
Thao M. Nguyen, Jingyu Liu, Vincent A. Hackley
Development of methods for the in situ fractionation and characterization of high aspect ratio (AR) gold nanorods (GNRs) is a rapidly growing area of interest within the nanotechnology field, particularly with respect to nanomanufacturing and biomedical applications. Monodispersed and high quality purified GNRs are essential for the advancement of technologies based on these materials. GNRs are of particular interest due to their unique optical properties, specifically their size-dependent absorption of the longitudinal surface plasmon resonance band. Used in concert, asymmetric-flow field flow fractionation (A4F) and single particle inductive coupled mass spectrometry (spICP-MS) provide unique advantages for fractionating and analyzing the typically complex mixtures produced by synthesis procedures commonly used for both research grade and commercial purposes. A4F fractions collected at specific elution times were analyzed off-line by spICP-MS. The particle masses within GNR populations were obtained by correlating the ICP-MS pulse intensity for individually detected particle events using mass standards of dissolved gold. Size distributions were then derived by transforming particle mass to length assuming a fixed diameter. The resulting particle lengths correlated closely with results obtained from transmission electron microscopy of samples collected from the same fractions. Of particular significance, and in contrast to our previously reported observations on the fractionation of low-AR GNRs (AR<4)1, under optimal A4F separation conditions it was observed in the present study that GNRs of fixed diameter (≈ 20 nm) appear to exhibit normal, rather than steric, mode elution (i.e., shorter rods with lower AR elute first). This study thus advances our understanding of the retention behavior of these asymmetric nanomaterials over a broad range of dimensional states.
, Liu, J.
and Hackley, V.
Fractionation and characterization of high aspect ratio gold nanorods using asymmetric-flow field flow fractionation and single particle inductively coupled plasma mass spectrometry, Chromatography, [online], https://doi.org/10.3390/chromatography2030422, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=918653
(Accessed December 2, 2023)