Imaging gold nanoparticles in mouse liver by laser ablation inductively coupled plasma mass spectrometry

Qing Li,Guoxia Zhang,Jiamei Mo,Yirui Chen,Zheng Wang,Chuchu Huang

doi:10.1038/s41598-017-03275-x

Abstract

Imaging the size distribution of metal nanoparticles (NPs) in a tissue has important implications in terms of evaluating NP toxicity. Microscopy techniques used to image tissue NPs are limited by complicated sample preparation or poor resolution. In this study, we developed a laser ablation (LA) system coupled to single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) for quantitative imaging of gold (G)NPs in tissue samples. In this system, GNPs were ablated but did not disintegrate and integrate under optimised operation conditions, which were verified by characterising LA particles by scanning electron microscopy. The feasibility of imaging size distributions in tissue was validated using reference GNPs 60 and 80 nm in size on matrix-matched kidney. A transport efficiency of 6.07% was obtained by LA-SP-ICP-MS under optimal conditions. We used this system to image 80-nm GNPs in mouse liver and the size distribution thus obtained was in accordance with that determined by nebuliser SP-ICP-MS. The images revealed that 80-nm GNPs mainly accumulate in the liver and did not obviously aggregate. Our results demonstrate that LA-SP-ICP-MS is an effective tool for evaluating the size distribution of metal NPs in tissue.

Highlights

In the past decade, metal nanoparticles (MNPs) have been widely used in biotechnology, manufacturing, and other areas due to their unique properties
In SP-ICP-MS, pulse frequency is directly related to NP concentration, and signal intensity is proportional to particle mass, which can be translated into size by assuming a spherical shape
laser ablation (LA)-SP-ICP-MS analysis of GNPs is mainly affected by laser fluence, which ensures that particles will not disintegrate and integrate into the LA process

Summary

Introduction

Metal nanoparticles (MNPs) have been widely used in biotechnology, manufacturing, and other areas due to their unique properties. Single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is considered as a promising analytical approach for the detection and characterisation of MNPs at low concentrations, as it allows simultaneous determination of particle size distribution and number[13,14,15,16]. Another study described a method for quantitative characterisation of GNPs involves coupling thin layer chromatography with laser ablation (LA)-ICP-MS and chemiluminescence[18, 19]. These approaches do not solve the problem of direct determination of size distribution in solid samples, namely biological tissues. The distribution of intravenously injected 80-nm GNPs in the liver was examined

Methods

Results

Conclusion