Uric acid c5h4n4o3

All the chemicals and reagents [thiophene monomer (C₄H₄S) (≥99% SRL), ferric chloride (FeCl₃) (≥98% AR), boron nitride bulk (h-BN) (≥99% SRL), sodium hydroxide (NaOH) (≥98% FISHER), acetonitrile, ethanol, methanol, 5-fluorouracil (C₄H₃FN₂O₂) (≥99% SRL), uric acid (C₅H₄N₄O₃) (≥99% SRL), lactose (C₁₂H₂₂O₁₁) (≥98% SRL), oxalic acid (≥99.5% AR), ascorbic acid (C₆H₈O₆) (≥99.7% SRL), dopamine (C₈H₁₁NO₂) (≥99% SRL), l-cysteine (C₃H₇NO₂S) (≥99% SRL), glucose (C₆H₁₂O₆) (≥99% SRL), potassium ferricyanide (C₆N₆FeK₃) (≥99% SRL), potassium ferrocyanide (C₆FeK₄N₆) (≥99% SRL), potassium chloride (KCl) (99.8% Fisher), monosodium hydrogen phosphate (NaH₂PO₄) (≥99% SRL), and disodium hydrogen phosphate (Na₂HPO₄) (≥99% SRL)] are purchased in Sigma Aldrich and Alfa Aesar. To create a stock solution, ultrapure deionized water was used. NaH₂PO₄ and Na₂HPO₄ were combined to create 0.1 M phosphate buffer (PBS) (pH = 7.0) for the detection of 5-Fu. The human blood serum sample was collected from SRM Medical College Hospital and Research Center, Kattankulathur, Tamil Nadu, for real sample analysis. All the experiments were done by using Milli-Q-water (18.2 MΩ cm @ 25 ± 2 °C).