Thiourea cs nh2 2

All chemicals were used as received: potassium cyanide (KCN, ≥98.0%, Sigma-Aldrich, St. Louis, MO, USA), thiourea (CS(NH₂)₂, ≥99.0%, Sigma-Aldrich, St. Louis, MO, USA), cadmium acetate (Cd(ac)₂, 99.995%, Sigma-Aldrich, St. Louis, MO, USA), aqueous ammonium hydroxide solution (28–30%, Acros Organics, Geel, Belgium), tin-doped indium oxide 20% suspension in water (ITO, 18 nm with In₂O₃/SnO₂ 90:10%, ≥99.0%, Sigma-Aldrich, St. Louis, MO, USA), ethanol (≥99.8%, Honeywell, Charlotte, NC, USA), acetone (≥99.5%, Honeywell, Charlotte, NC, USA), and isopropanol (≥99.8%, Honeywell, Charlotte, NC, USA). Ultrapure water (MQ water, 18.2 MΩ cm) was generated using a Milli-Q Advantage A10 Millipore system (Millipore, Burlington, MA, USA).

Nickel (II) nitrate hexahydrate (Ni(NO₃)₂ 6H₂O) and thiourea (CS(NH₂)₂) were acquired from Sigma Aldrich. Potassium hydroxide pellet (KOH) was obtained from SRL. Nitric acid (HNO₃) was received from Rankem analytic. Glucose (Glu) (C₆H₁₂O₆), ascorbic acid (C₆H₈O₆) (AA), uric acid (C₅H₄N₄O₃) (UA), paracetamol (C₈H₉NO₂) (PA), magnesium sulfate hexahydrate (MgSO₄·6H₂O), sodium chloride (NaCl), and calcium sulfate pentahydrate (CaSO₄·5H₂O) were obtained from Sigma Aldrich. Millipore Milli-Q nanopure water (resistivity ≥18 MΩ cm⁻¹) system was used as the solvent throughout this work. All the reagents obtained and used in this work were of analytical grade, and were applied without further refinement. Human serum samples were provided by the SRM medical college hospital and the human urine samples were collected from healthy volunteers.