Graphene oxide from silk cocoon: a novel magnetic fluorophore for multi-photon imaging

Abstract

In this work, we synthesized graphene oxide from silk cocoon embarking its new dimension as a magnetic fluorophore when compared with its present technical status, which at best is for extracting silk as a biomaterial for tissue engineering applications. We produced graphene oxide by pyrolysing the silk cocoon in an inert atmosphere. The collected raw carbon is oxidized by nitric acid that readily produces multilayer graphene oxide with nano carbon particulates. Structural properties of the graphene oxide were analyzed using scanning electron microscopy, transmission electron microscopy, Fourier transform infra-red spectroscopy, and Raman spectroscopy. The oxidized sample shows remarkable fluorescence, multi-photon imaging and magnetic properties. On increasing the excitation wavelength, the fluorescence emission intensity of the graphene oxide also increases and found maximum emission at 380 nm excitation wavelength. On studying the two photon absorption (TPA) property of aqueous graphene oxide using Z-scan technique, we found significant TPA activity at near infrared wavelength. In addition, the graphene oxide shows ferromagnetic behavior at room temperature. The observed fluorescence and magnetic property were attributed to the defects caused in the graphene oxide structure by introducing oxygen containing hydrophilic groups during the oxidation process. Previously silk cocoon has been used extensively in deriving silk-based tissue engineering materials and as gas filter. Here we show a novel application of silk cocoon by synthesizing graphene oxide based magnetic-fluorophore for bio-imaging applications.Electronic supplementary materialThe online version of this article (doi:10.1007/s13205-013-0128-2) contains supplementary material, which is available to authorized users.

Biocharring of natural fibers of insect and plant origin: a green route for the production of ‘carbon-based charge storage nanomaterials’

“…Tassar cocoon, Mulberry cocoon and, Tassar silk thread show sheet-like structure as shown in Fig. 4e-g, respectively [7,9], and Jute exhibits thin tube-like structure as shown in Fig. 4h [6].…”

“…The 2D band is most likely suppressed by "Pauli blocking effect" [23][24][25][26][27][28]. FTIR spectra are shown in [6,7,9].…”

“Induced Electron Transfer” in Silk Cocoon Derived N-Doped Reduced Graphene Oxide-Mo-Li-S Electrode

“…Preparation of NDRGO Tassar silk cocoon were obtained from the forest reserves of the state of Chhattisgarh in India as described in our previous work (Roy et al, 2014;Sahu et al, 2015;Dubey et al, 2018;Jangir et al, 2018). The dead pupae was removed and the Tassar silk cocoon was cut into small pieces and was then put into a crucible.…”

“…About 0.5 g of the above sample was treated in 30 ml of hydrazine hydrate at approximately 40 • C for 12 h. The insoluble reduced graphene oxide so formed was washed with water followed by methanol and acetone sequentially and dried in a desiccator. This sample is termed as nitrogen doped reduced graphene oxide (NDRGO) (Roy et al, 2014;Sahu et al, 2015;Dubey et al, 2018;Jangir et al, 2018).…”

Extraction of preformed graphene oxide from coal: its clenched fist form entrapping large molecules

“…However, simple carbonization of natural organic wastes or even roasted food under burbeque led to the formation of GO . 8,9 This suggests that during the bio-geochemical coalification of plant materials the increase in carbon content from the starting peat stage to the end anthracite version of the coal , the metamorphic transformation of the carbonaceous mass proceeded in the reverse direction as we work today to synthesize graphene oxide. Plant materials are composed mainly of carbon, oxygen, hydrogen, nitrogen and sulphur.…”