Intracellular label-free gold nanorods imaging with photoacoustic microscopy

Sihua Yang,Da Xing,Fei Ye

doi:10.1364/oe.20.010370

Abstract

Noninvasive photoacoustic microscopy was developed to image intracellular gold nanorods with high optical-absorption contrast. The endocytosed gold nanorods in MCF7 cells can be detected and imaged with the home-made photoacoustic microscope. Cell nucleus and gold nanorods in cytoplasm were clearly identified after hematoxylin and eosin (H&E) staining with dual-wavelength excitation. The intracellular gold nanorods were successfully monitored, and that the time-dependent uptake and distribution of the gold nanorods in the cells were clearly shown. The result demonstrated an application of photoacoustic microscopy for complements to imaging of nonfluorescent nanoparticles, which will arm the in vivo microscopic imaging method to the nano-bio research.

Highlights

Nanoengineered particles possess great potential for biological and medicinal application, all such materials are subject to a preclinical evaluation process commonly referred to as adsorption, distribution, metabolism, excretion, and toxicity [1,2], which are not yet well defined, stimulating much discussion and research in the area
To measure the transverse spatial resolution of the photoacoustic microscope, gold nanospheres with a diameter of ~60 nm were scanned by the system with 532 nm wavelength laser
The experimental result demonstrated that the transverse spatial resolution of the photoacoustic microscope system can reach nano scale for cell imaging

Summary

Introduction

Nanoengineered particles possess great potential for biological and medicinal application, all such materials are subject to a preclinical evaluation process commonly referred to as adsorption, distribution, metabolism, excretion, and toxicity [1,2], which are not yet well defined, stimulating much discussion and research in the area. Gold nanorods are usually characterized by UV-Vis spectrophotometry, inductively coupled plasma atomic emission spectroscopy (ICP-AES), and transmission electron micros-copy (TEM), but these techniques could not be used for in vivo or living cells detection. Laser confocal fluorescence microscopy and two-photon fluorescence microscopy are the most commonly methods to trace and image the gold nanoparticles for cells imaging [6,7,8]. Confocal Raman scattering microscopy and photothermal microscopy have been introduced to detect nano-objects and cellular components [9,10,11,12]

Methods

Results

Conclusion