Fluorescent Nanowire Heterostructures as a Versatile Tool for Biology Applications

Abstract

Nanowires are increasingly used in biology, as sensors, as injection devices, and as model systems for toxicity studies. Currently, in situ visualization of nanowires in biological media is done using organic dyes, which are prone to photobleaching, or using microscopy methods which either yield poor resolution or require a sophisticated setup. Here we show that inherently fluorescent nanowire axial heterostructures can be used to localize and identify nanowires in cells and tissue. By synthesizing GaP-GaInP nanowire heterostructures, with nonfluorescent GaP segments and fluorescent GaInP segments, we created a barcode labeling system enabling the distinction of the nanowire morphological and chemical properties using fluorescence microscopy. The GaInP photoluminescence stability, combined with the fact that the nanowires can be coated with different materials while retaining their fluorescence, make these nanowires promising tools for biological and nanotoxicological studies.

Ground State Depletion Nanoscopy Resolves Semiconductor Nanowire Barcode Segments at Room Temperature

“…NWs have been indirectly visualized as dark spots due to spatial exclusion within labeled cells 17,18 or were directly labeled with fluorescent organic dyes. 19−21 To circumvent bleaching issues associated with these methods, it has been recently proposed 22 to use the intrinsic photoluminescence of NW heterostructures as contrast method for their visualization in biological systems. 22,23 However, the diffraction-limited resolution of conventional lens-based microscopy restricts the amount of information that can be extracted from such images.…”

“…Next, we proceeded to explore the imaging of barcode NWs 22 (Figures 3–5). We imaged NWs that were synthesized to have a diameter of ∼20 nm and consisted of four GaInP PL segments (233 ± 40 nm length) separated by nonluminescent GaP segments (164 ± 21 nm), as characterized by SEM.…”

Quantitative determination of uric acid using CdTe nanoparticles as fluorescence probes

“…Semiconductor nanoparticles (NPs) have attracted great interest in both fundamental research and technical applications, for example, in biological labeling (Adolfsson et al 2013; Kim et al 2015), LED displays (Mansur 2010), and solar cells (Kumar et al 2015;Pan et al 2013;Reiss et al 2009), due to their unique properties such as size-dependent tunable emission, narrow emission bandwidth, broad excitation, strong absorption abilities, and good photo-stability. Traditionally, the approach that was followed to enhance the quantum efficiency of NPs required the synthesis in organic media using several techniques including core/shell nanocrystal construction (Huy et al 2014b) and pyrolysis .…”

(Ga,In)P nanowires grown without intentional catalyst

“…It is a material largely used in optical applications such as light-emitting devices, solar cells and heterojunction structures [11,8,12]. The inherently fluorescence of the (Ga,In)P makes it a promising tool for biological applications [13].…”