Agar-Well Diffusion Method

The agar-well diffusion approach was used to assess the antimicrobial activity of 1 mg/mL of Nos@AgNPs, AgNO₃, Ch@AgNPs, algal extract, and 5 µg/mL ciprofloxacin against all tested bacteria as follows: 4 mL of bacterial suspension (2.5–3.6 × 10⁶ CFU/mL) was suspended in 50 mL of nutrient agar media. The mixture was poured into sterile Petri dishes and dried at 37 °C. Wells (8-mm diameter) were created on the agar plates using a cork borer. Subsequently, 100 μL of Nos@AgNPs, AgNO₃, Ch@AgNPs, ciprofloxacin, and algal extract suspensions were poured into the 8 mm wells. The plates were placed in a bacterial incubator at 37 °C for 24 h. Diameters of the inhibition zone (mm) were determined using a transparent ruler.²