Sunlight-induced rapid and efficient biogenic synthesis of silver nanoparticles using aqueous leaf extract of Ocimum sanctum Linn. with enhanced antibacterial activity

Organic and Medicinal Chemistry Letters

Table 1 Count of colony forming units of different pathogenic bacteria and the AgNPs

Microorganism	Control (untreated)	10⁻³M AgNO₃Solution	5% PLE	AgNPs formed by 5% PLE	7% PLE	AgNPs formed by 7% PLE	10% PLE	AgNPs formed by 10% PLE
Staphylococcus aureus	1.2 × 10⁹	0.5 × 10²	1.4 × 10²	0.01 × 10²	1.7 × 10²	0	0.7 × 10²	0.02 × 10²
Bacillus subtilis	6.0 × 10⁸	1.0 × 10³	5.2 × 10³	0.5 × 10²	4.8 × 10³	0.3 × 10²	3.5 × 10³	0.3 × 10²
Listeria monocytogenes	7.0 × 10⁸	2.0 × 10²	1.2 × 10³	0.1 × 10²	9.0 × 10²	0.09 × 10²	5.6 × 10²	1.0 × 10²
Staphylococcus epidermidis	1.5 × 10⁹	2.0 × 10²	5.0 × 10²	0.8 × 10²	3.7 × 10²	0.05 × 10²	3.0 × 10²	0.08 × 10²
Salmonella typhimurium	8.0 × 10⁸	1.5 × 10³	6.0 × 10³	0.8 × 10²	5.5 × 10³	0.5 × 10²	4.5 × 10³	0.7 × 10²
Pseudomonas aeruginosa	8.5 × 10⁸	6.0 × 10²	7.2 × 10³	0.4 × 10²	7.0 × 10³	0.04 × 10²	6.9 × 10³	0.4 × 10²
Escherichia coli	8.0 × 10⁸	1.3 × 10³	2.0 × 10³	1.2 × 10²	1.5 × 10³	0.8 × 10²	8 × 10²	0.9 × 10²
Pantoea ananatis	8.5 × 10⁸	7.0 × 10²	4.0 × 10³	0.06 × 10²	1.7 × 10³	0.04 × 10²	9 × 10²	0.05 × 10²

After overnight growth upon treatment with different concentration of aqueous leaf extract of Ocimum sanctum and the AgNPs (dispersed in the aqueous leaf extract) formed by them upon sunlight induction. AgNPs, silver nanoparticles dispersed in the aqueous leaf extract; PLE, plant leaf extract.