Methyl 4 formylbenzoate

4-Hydroxybenzaldehyde, methyl 4-formylbenzoate, pyrrole, Zinc tetraphenyl-porphyrin (ZnTPP), anhydrous zinc acetate, anhydrous indium (III) chloride, gallium (III) chloride and N,N’-dicyclohexylcarbodiimide (DCC) and N-hydroxysuccinimide (NHS), tryptic soy broth, crystal violet and 9,10 dimethylanthracene (DMA) were purchased from Sigma-Aldrich.
The synthesis of silver nanoparticles was done following a procedure described in literature (Agnihotri et al., 2014 (link)). Detonation nanodiamonds (DNDs) were obtained from the Nanocarbon Research Institute Ltd.
Dimethylformamide (DMF), dimethylsulfoxide (DMSO) and all other reagents were obtained from commercial suppliers and were of analytical grade purity and used without further purification. For sample purification, silica gel 60 (0.04–0.063 mm) was used for column chromatography.
The antibacterial experiments were carried out using Staphylococcus aureus obtained from Davies Diagnostics, South Africa. The nutrient agar and nutrient broth used to evaluate the bacteria growth and to feed the biofilms were purchased from Merk (Pty) Ltd. South Africa. Phosphate buffer saline (10 mM PBS, pH 7.4) was prepared using appropriate amounts of Na₂HPO₄ and NaOH using highly purified H₂O from ELGA, Veolia water PURELAB, Flex system (Marlow, United Kingdom).

All reagents were of analytical grade and utilized without further purification. Zirconium(IV) chloride (ZrCl₄), methyl 4-formylbenzoate (C₉H₈O₃), pyrrole (C₄H₅N), benzoic acid (C₇H₆O₂), Iron(II) chloride tetrahydrate (FeCl₂·4H₂O), propionic acid (C₃H₈O₂) Chloroform (CHCl₃), ethanol (C₂H₆O), methanol (CH₄O), glucose, sucrose, fructose, sodium ascorbate, cyclamate, hydrochloric acid (HCl), N,Nʹ-dimethyl formamide (DMF), sodium hydroxide (NaOH) and tetrahydrofuran (THF) were obtained from Sigma-Aldrich Chemical Company (MO, USA). Reagent grade aspartame was obtained from Merck KGaA (Darmstadt, Germany). Milli-Q^® (Merck-Millipore, MA, USA) water (18.3 MΩ cm⁻¹) was used throughout all experiments. A stock standard solution of aspartame (1000 mg L⁻¹) was prepared by dissolving 1.0000 g of it in 1000 mL of distilled water. Working standard solutions were prepared by serial dilutions of the stock solution prior to analysis.