Tetrachloroauric acid haucl4

Tetrachloroauric acid (HAuCl₄) and DMSO-d₆ were purchased from Sigma Aldrich (Saint Louis, MO, USA). Abiraterone and acetate abiraterone (batch Nos. 219595 and 217728, respectively) were obtained from Molekula SRL (Rimini, Italy). Dimethyl sulfoxide and dimethylformamide (GC-headspace tested 99.9%) were purchased from Aldrich. Other chemical reagents used in this study were obtained from POCH (Gliwice, Poland). All solutions were prepared with ultrapure water (18.2 MΩ) purified on the Polwater System D-300 (Cracow, Poland). Deuterated solvents for NMR spectroscopy were purchased from ARMAR AG (Döttingen, Switzerland).

n-Heptane (Hp) from Merck, HPLC grade, was used without further purification. Sodium 1,4-bis (2-ethylhexyl) sulfosuccinate (AOT) (Sigma greater than 99% purity) was used as received and to minimize water absorption it was kept under vacuum over P₂O₅. Ultrapure water was obtained from Labonco equipment model 90901-01. Tetrachloroauric acid (HAuCl₄, Sigma-Aldrich) as precursor and hydrazine monohydrate (N₂H₄·H₂O, Sigma-Aldrich) as reducing agent, both for the synthesis of Au-NPs were used as received.

The citrate reduction process was used to synthesize AuNPs [92 (link)]. Before synthesis, all the glassware was rinsed with aqua regia and washed thoroughly with distilled water. Briefly, a 20 mL aqueous solution of 0.1 mg/mL Tetrachloroauric acid (HAuCl_4; 99% pure, Sigma-Aldrich, Burlington, USA) was used as a metallic precursor and allowed to heat to the point of boiling. Then 2 mL of the reducing agent, 1% sodium citrate solution, was added instantly and stirred for 10 min. Infographic, Fig. 1A, illustrates the reaction scheme for preparing AuNPs.

Spherical 15 nm AuNPs were synthesized via citric acid reduction using principles of the Turkevic synthesis method [54 (link),55 (link)]. Tetrachloroauric Acid (HAuCl₄) and sodium citrate dihydrate were purchased from Sigma-Aldrich. After 100 mL of 0.3 mM HAuCl₄ had been heated to boiling, 2 mL of 34 mM sodium citrate solution was immediately mixed with the gold solution. This mixture was stirred with heating for an additional 20 min before being cooled to room temperature. The cooled solution was then centrifuged for 45 min at 9000× g. The concentrated AuNP sample was then extracted and sonicated for 6 min (in 1-min intervals) at a power level of 1 on a Branson sonicator. The sonicated sample was characterized via UV-visible spectroscopy, dynamic light scattering, and transmission electron microscopy for size and conformity [37 (link)]. For 15 nm AuNPs, it was expected that the maximum absorbance should be at 520 nm with an extinction coefficient of 3.9 × 10⁸ M⁻¹ cm⁻¹ [56 (link),57 (link),58 (link),59 (link)].

Acenaphthene (Ace) (purity > 99%), phenanthrene (Phe) (purity ≥ 98%), iron(II) chloride tetrahydrate (purity > 99%), iron(III) chloride (purity > 98%), nickel(II) chloride hexahydrate (purity ≥ 97%), oxalic acid (purity ≥ 98%), sodium nitrite (purity ≥ 98.5%), sodium perchlorate (purity ≥ 99%), and tin(IV) chloride pentahydrate (purity ≥ 98%) were purchased from Acros Organics (Geel, Belgium). Acetic acid (purity ≥ 99.7%), nitric acid (purity > 68%), phosphate-buffered saline (PBS) buffer solution, and sodium carbonate (purity > 99.5%) were obtained from Fisher Chemical (Hampton, NH, USA). Copper (II) chloride (purity ≥ 98%), fluorine (Flu) (purity ≥ 98%), naphthalene (Nap) (purity ≥ 99%), and zinc chloride (purity ≥ 98%) were purchased from Alfa Aesar (Ward Hill, MA, USA). Potassium acetate (purity ≥ 99%) and tetrachloroauric acid (HAuCl₄) (purity ≥ 99.99%) were purchased from Sigma–Aldrich (St. Louis, MO, USA). Sodium citrate (purity ≥ 99%) was obtained from Macron Fine Chemicals (Center Valley, PA, USA). All chemicals used were of analytical grade and were used without undergoing additional purification.