Preparation, Characterization and Intracellular Imaging of 2,4-Dichlorophenoxyacetic Acid Conjugated Gold Nanorods.

Visualizing the biodistribution of pesticides inside living cells is great importance for enhancing targeting of pesticides. Here we reported for the first time that gold nanorods (Au NRs) with size of 39.4 nm x 11.3 nm could be used as a fluorescent tracer to examine the distribution of a typical herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), in tobacco bright yellow 2 (BY-2) cells. The nanostructures of hybrid materials were analyzed by using Raman spectra and X-ray photoelectron spectroscopy (XPS), including spectra assignments and electronic property. These data revealed 2,4-D has successfully conjugated MP-Au NRs according to Raman and XPS. The biodistribution of the conjugates inside BY-2 cells was directly examined at 12 and 24 h by the two-photon microscopy. The intensity of two-photon luminescence (TPL) inside cells demonstrated that the conjugates could be localized and excluded by BY-2 cells. Thus, this labeling approach opens up new avenues to the facile and efficient labeling of pesticides.

Biosynthesis of Gold Nanoparticles Using Novel Bamboo (Bambusa chungii) Leaf Extracts.

Gold nanoparticles (Au NPs) have drawn significant interest because of their antisotropic physical properties in biomedical applications. In this paper, we reported the application of bamboo (Bambusa chung) leaf extracts, previously not exploited, in the synthesis of Au NPs at ambient temperature. The average dimension of quasi-spherical Au NPs was 28.8±4.5 nm by transmission electron microscopy (TEM). The UV-vis spectroscopy gave an optimal reaction time of 180 min in the process of bioreduction. The organic shell of Au NPs was characterized by Fourier transform infrared (FTIR) spectra and thermogravimetric analysis (TGA), suggesting that the main compositions of the organic shell were hydroxyflavones. The X-ray diffraction (XRD) studies indicated the Au NPs were (111) oriented. This eco-friendly method for the synthesis of Au NPs was simple, amenable for large scale commercial production and biological applications to future in vivo imaging and cancer therapy.