Synthesis of gemifloxacin conjugated silver nanoparticles, their amplified bacterial efficacy against human pathogen and their morphological study via TEM analysis

Figures & data

Figure 1. Molecular structure of gemifloxacin.

Figure 2. UV–Vis spectra of AgNO₃, Gemi-AgNPs, and gemifloxacin.

Figure 3. Reaction optimization of Gemi-AgNPs.

Figure 4. Effect of different pH values (2–13) on the stability of Gemi-AgNPs.

Figure 5. Stability of Gemi-AgNPs at different ranges of temperature.

Figure 6. FTIR spectra of gemifloxacin and Gemi-AgNPs.

Figure 7. Mechanism of the interaction between AgNPs and Gemifloxacin.

Table 1. FTIR spectral assignment of free gemifloxacin and Gemi-AgNPs.

Free gemifloxacin	Gemi-AgNPs	Assignment
3398 cm^−1	—	v (NH2)/(–OH)
1680 cm^−1	1680 cm^−1	v (–C=O)
1680 cm^−1	1669 cm^−1	v (C=C)

Figure 8. Particle-size distribution of Gemi-AgNPs using AFM.

Figure 9. TEM images showing round-shaped Gemi-AgNPs.

Figure 10. Particle-size distribution of Gemi-AgNPs.

Table 2. Biofilm inhibition of gemifloxacin and Gemi-AgNPs.

Organism	Gemifloxacin			Gemi-AgNPs
	Dose (ug/mL)		Biofilm % inhibition ± SD	Dose (ug/mL)		Biofilm % inhibition ± SD
	MIC	MBIC	AVG	MIC	MBIC	AVG
E. aerogenes	32	8	21.14 ± 4.8	8	4	37.7 ± 3.2
E. faecalis	8	4	77.39 ± 3.3	8	4	67.47 ± 0.7
K. pneumoniae	0.125	0.063	92.89 ± 0.4	4	4	33.20 ± 6.1
P. mirabilis	4	4	44.60 ± 3.3	4	4	28.60 ± 2.0
S. mutans	0.4	0.2	87.49 ± 1.1	0.2	0.05	88.29 ± 1.8
MRSA	0.05	0.0125	90.20 ± 5.3	0.025	0.003	95.12 ± 2.4
E. coli	0.125	0.063	89.30 ± 1.6	4	4	41.6 ± 1.8

Figure 11. Light microscopic evaluation of MRSA after treatment with Gemi-AgNPs and Gemifloxacin.

Table 3. Biofilm eradication of gemifloxacin and Gemi-AgNPs.

Organism	Gemifloxacin			Gemi-AgNPs
	Biofilm eradication dose (ug/mL)	Biofilm % eradication	Biofilm (%) viability reduction	Biofilm eradication dose (ug/mL)	Biofilm % eradication	Biofilm (%) viability reduction
		AVG ± SD	AVG ± SD		AVG ± SD	AVG ± SD
MRSA	10	59.6 ± 8.1	60.1 ± 6.9	1	59.5 ± 4.3	33.62 ± 1.2
K. pneumoniae	10	33.70 ± 3.2	N/A	10	21.4 ± 3.2	N/A
S. mutans	10	IA	N/A	1	49.3 ± 1.3	N/A

Figure 12. Cell wall damage of K. pneumoniae. (a) Untreated K. pneumoniae at 500 nm and (b) at 1 µm was used as control, whereas (c) present the bacterial cell wall damage of K. pneumoniae after treatment with Gemi-AgNPs at 200 nm and (d) at 1 µm.

Figure 13. Cell wall damage of E. aerogenes. (a) Untreated E. aerogenes at 1 µm and (b) at 500 nm were used as control, whereas (c) and (d) present the bacterial cell wall damage of E. aerogenes after treatment with Gemi-AgNPs at 500 nm.

Figure 14. Cell wall damage of E. coli. (a) Untreated E. coli at 1 µm and (b) at 2 µm used as control, whereas (c) present the bacterial cell wall damage of E. coli after treatment with Gemi-AgNPs at 1 µm and (d) at 2 µm.

Data availability statement

All data is included in the submission/manuscript file.