Table 1.

The average zones of inhibition (in mm) of rGO, nAg, rGO–nAg, and nitrofurantoin.

Isolates	P. mirabilis	E. coli	S. aureus
rGO
50 µg/ml	No zone	No zone	No zone
100 µg/ml	No zone	No zone	No zone
200 µg/ml	18 ± 2	9 ± 1	No zone
nAg
100 µg/ml	No zone	No zone	8 ± 1
rGO–nAg
100 µg/ml	23 ± 2	25 ± 2	24 ± 1
Nitrofurantoin
100 µg/ml	24 ± 2	No zone	26 ± 1

As expected, the zone of inhibition for rGO and nAg was concentration-dependent. The concentrations of 50 µg/ml and 100 µg/ml of rGO and nAg, respectively, were insufficient to inhibit the organisms tested. At these concentrations, nitrofurantoin inhibited P. mirabilis and S. aureus, but not E. coli. rGO–nAg nanomaterial composite showed strong activity, inhibiting all pathogens tested, including E. coli shown to be resistant to standard antibiotic.