Graphite fine powder

The graphite fine powder (spectroscopic grade, particle size ≤ 50 μm), phosphoric acid (85%), sulfuric acid (98%), potassium permanganate (KMnO₄), hydrochloric acid (36%), AA (C₆H₈O₆), ferrous sulfate heptahydrate, Iron(III) chloride hexahydrate, ammonium hydroxide, Nafion (5% EtOH solution), aluminum oxide, potassium ferricyanide and potassium ferrocyanide were purchased from Merck. N-hydroxysuccinimide (NHS, 98%), 1-Ethyl-3-(3 dimethylaminopropyl) carbodiimide, hydrochloride (EDC, 98%), PBS (phosphate buffered saline), bovine serum albumin (BSA), and aniline (99.5%) were purchased from Sigma-Aldrich. All solutions were prepared using deionized water. Herceptin was obtained from Institute of BioChemistry and Biophysics (IBB, Iran). SK-BR3, MCF7, and LO2 cell lines were obtained from Shahid Beheshti University of Medical Sciences. Glassy carbon electrodes (GCE) were purchased from Azar Elect.

All the chemicals used in this investigation were AR-grade materials and used without further purification. Cobalt Acetate (II) tetrahydrate ((CH₃COO)₂Co.4H₂O 95%), was purchased from Loba Chemie. Ethanol absolute (C₂H₅OH 99%), potassium permanganate (KMnO₄) and hydrogen peroxide (H₂O₂ 30% Extra pure) were purchased from Scharlau. De-ionized water was used to prepare aqueous solutions. Hydrochloric acid (HCl > 37%) was purchased from Sigma Aldrich. Graphite fine powder extra pure (<50 μm, 99.5%) and sodium nitrate crystal extra pure (NaNO₃) were purchased from Merck. On the other hand, Boron Nitride (BN) Micropowder (98% purity) was purchased from Graphene Supermarket.

Polyaniline (PANi, 99%), Polymethyl methacrylate (PMMA, M_w~120,000), Poly (propylene glycol)-block-Poly(ethylene glycol)-block-poly(propylene glycol) (PPG-b-PEG-b-PPG, M_n~4400) and fine graphite powder (99%) were purchased from Sigma-Aldrich (St Louis, MO, US). Other reagents such as nitric acid (HNO₃, 70%), hydrochloric acid (HCl, 37%), potassium dichromate (K₂Cr₂O₇, 99.99%) and dichloromethane (DCM) were also procured from Sigma-Aldrich and used as received.

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.

Polycaprolactone (PCL; Mw 80,000 g/mol) and bovine skin Gt Type B were purchased from Sigma Aldrich, Darmstadt, Germany. ACS-grade chloroform (CF), dimethyl sulfoxide (DMSO; max. 0.025% H₂O), and LC–MS-grade water for chromatography were purchased from Merck, Darmstadt, Germany. Fine graphite powder, sodium nitrate (>99%), potassium permanganate (>99%), sulfuric acid (>95%), and hydrogen peroxide (30%) were purchased from Sigma-Aldrich, Darmstadt, Germany. Resazurin sodium salt (80% dye content) was purchased from Santa Cruz Biotechnology, Dallas, Texas, USA. Polydimethylsiloxane (PDMS) was purchased from Dow Corning Corporation, Midland, Michigan, USA, and high-glucose Dulbecco’s Modified Eagle Medium was purchased from Gibco, Grand Island, NY, USA.