When Mass Spectrometry Meets Nanoparticles:
Integrating Functionalized Gold Nanoparticles with Mass Spectrometric Analysis

Therapeutic nanocarriers are nanoscale vehicles that carry drugs, genes and/or imaging agents into cells, tissues and organs of interests. Gold nanoparticles (AuNPs) represent highly promising candidates as therapeutic nanocarriers. The tunable surface functionality of AuNPs provides appealing design flexibility to ensure specific targeting, efficient cellular uptake and controllable release. Effective development of AuNPs as nanocarriers requires the ability to monitor AuNPs in cells, tissues and/or organs. My current research involves the use of mass spectrometry to monitor functionalized AuNPs in biological matrix (e.g. cells and tissues). Currently, we have established a novel laser desorption/ionization mass spectrometry (LDI-MS) methodology for the multiplexed screening of cellular uptake of AuNP. In this experiment, surface functionalities of AuNP in cell lysate could be readily detected by LDI-MS, thus providing identification and quantification of cellular uptake of AuNPs. This methodology has great potential for both the development of AuNP-based delivery vectors and for probing transport of nanomaterials in vitro and in vivo.

My second project involves using various functionalized AuNPs to develop new selective extraction agents. Chemical compounds (e.g. peptides) from ultra dilute and/or complicated solutions could be selectively extracted/concentrated by functionalized AuNPs, following by the analysis of MALDI-MS. As extraction agents, AuNPs have a higher surface area-to-volume ratio, thus resulting in greater extraction capacity. And, such an extraction is also coupled with a significant preconcentration effect. In addition to higher surface area-to-volume ratio, the tunable surface chemistry of AuNPs enables particles to selectively recognize a particular class of compounds.

Figure 1. Schematic illustration of integrating AuNPs into mass spectrometric analyses: AuNPs in complex biological samples could be screened by LDI-MS, while these AuNPs also provide specific extraction of biomolecules for MALDI analysis.