Tetrachloroauric 3 acid trihydrate

Tetrachloroauric (III) acid trihydrate (HAuCl₄·3H₂O, ≥99.5%) and ethylenediaminetetraacetic acid (EDTA, ≥98.0%) were purchased from Merck (Darmstadt, Germany). Trisodium citrate dihydrate (TSC, ≥99.0%) were purchased from Prolabo (Kennersburg, NJ, USA). Deionized (DI) water (>18 MW, Millipore, Darmstadt, Germany) was used during the synthesis of AuNSps. A commercial product, called TOPSIN M 70WP (containing 70% of thiophanate methyl), was purchased from Nippon Soda Company, Ltd. All reagents were used without further purification.
The morphology of the as-synthesized samples was obtained by scanning electron microscopy (Hitachi, Horiba S-4300) coupling with energy-dispersive X-ray (EDX) spectroscopy operated at 20 kV of the incident electron beam energy. Transmission electron microscope (TEM) images were obtained with a JEOL JEM-1400 (120 kV). X-ray diffractometer (XRD, Bruker D8 advance powder diffractometer model) with Cu Kα radiation (λ = 1.54056 Å) operated at 40 kV and 30 mA with a scanning rate of 0.02° per step in the 2θ range of 10° ≤ 2θ ≤ 90° was carried out to characterize the crystal structure of AuNSps. UV-vis spectroscopy (UV-Vis-NIR-V670, JASCO, Tokyo, Japan) was utilized to investigate the optical properties of AuNSps. The Raman spectra of AuNSps samples were recorded on a LabRam HR micro-Raman instrument with a 532 nm Ar+ ion laser at room temperature.

Fine graphite powder (<50 μm) was received from Sigma-Aldrich, India. Tetrachloroauric (III) acid trihydrate, chitosan, sulfuric acid (AR grade), potassium permanganate, hydrogen peroxide (30%), sodium nitrate, sodium nitrite, sodium fluoride, sodium bromide, sodium thiocyanate, calcium oxalate, disodium phosphate, sodium bicarbonate, sodium sulphate, and succinic acid were obtained from Merck, India. All chemicals were of analytical grade and used as received. The stock solutions were prepared using doubly distilled water and the experiments were performed under ambient conditions.
UV–vis spectral measurements were performed using a Jasco (V-560) spectrometer. The morphological studies of the as-synthesized composite were characterized by FEI Tecnai G2 20 S-TWIN TEM with an accelerating voltage of 200 kV. FEI Tecnai G2 20 S-TWIN TEM attached BRUKER AXS elemental analyzer was used for the EDS and elemental mapping of the composite. XRD analysis was performed using from Panalytical X′ per PRO X-ray diffractometer equipped with Cu Kα radiation (λ = 0.15406 nm). FTIR was performed by a Shimadzu model FT-IR spectrometer.

Tetrachloroauric (III) acid trihydrate (HAuCl₄·3H₂O, 99.9%), acetic acid (CH₃COOH, 99.5%), and ascorbic acid (C₆H₈O₆, 99.7%) were purchased from Merck (Darmstadt, Germany). Chitosan (CS, (C₁₂H₂₄N₂O₉)_n, >75% deacetylated, M_w 310 000–375 000 Dalton) was purchased from Sigma-Aldrich (St. Louis, MO, USA), and used without post-modification. Collagenase Type 1A, fetal bovine serum (FBS), l-glutamine, (4-(2-hydroxyethyl) piperazine-1-ethane sulfonic acid) (HEPES. 99.5%), anti-vimentin/anti-cytokeratin 19 anti-bodies, amphotericin B, penicillin G, and streptomycin were obtained from Sigma-Aldrich (St. Louis, Missouri, USA). Gibco Dulbecco's Modified Eagle Medium: nutrient mixture F12 (DMEM/F12) was purchased from Thermo Fisher Scientific (Waltham, MA, USA).
Chemicals are analytical grade and used without further purification, and the deionized water (conductivity below 4.3 μS cm⁻¹) was used in all the aqueous phase experiments.