## 4 Conclusions  
Herein, nitrogen-doped graphene was successfully synthesized by using the one-pot facile synthesis of NDG, wherein the NDG was prepared by the reduction of graphene oxide in the presence of hydrazine hydrate as a reducing agent, while ammonium hydroxide was used as a source of nitrogen on the surface of graphene and also investigated their anticancer, antimicrobial, and biofilm inhibition activity. NDG exhibited better activity against methicillin-resistant _Staphylococcus aureus_ (MRSA), _Bacillus subtilis_, _Streptococcus pneumoniae_, and _Streptococcus mutans_ (\(p\leq 0.05\)), whereas there was no activity against Gram-negative strains in _Klebsiella pneumoniae_ and _Pseudomonas aeruginosa_. Furthermore, the biofilm inhibition activity of NDG against _Pseudomonas aeruginosa_ showed the least MIC of 25 ug/mL and showed the highest percentage of inhibition 96.26 with  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**S. No** & **Tested Microorganism** & **Drug** & **MIC (ug/mL)** & **Parentage of Inhibition** & **IC\({}_{50}\) (ug)** \\ \hline \multirow{4}{*}{1} & \multirow{4}{*}{_P. aeruginosa_} & NDG & 25 & 94.26 & 12.98 \\ \cline{3-6}  & & NDG & 50 & 94.23 & 26.53 \\ \cline{3-6}  & & Ampicillin & 1000 & 90.45 & 110.55 \\ \cline{3-6}  & & Ampicillin & 2000 & 91.31 & 547.58 \\ \hline \multirow{4}{*}{2} & \multirow{4}{*}{MRSA} & NDG & 50 & 98.12 & 23.11 \\ \cline{3-6}  & & NDG & 100 & 93.76 & 53.32 \\ \cline{3-6}  & & Ampicillin & 200 & 89.79 & 111.37 \\ \cline{1-1} \cline{3-6}  & & Ampicillin & 1000 & 91.07 & 137.25 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Evaluation of MIC, percentage inhibition, and IC\({}_{50}\) values of NDG and Ampicillin.  
Figure 9: Cytotoxicity after 24 h of incubation with NDG (**A**); MCF-7 cells (**B**) HeLa cells with IC\({}_{50}\) values (ug/mL).  
an IC\({}_{50}\) value of 12.98 \(\upmu\)g/mL in comparison to standard antibiotics tested. The results with MRSA biofilm inhibition activity of NDG showed an IC\({}_{50}\) value of 23.11 \(\upmu\)g/mL with an inhibition percentage of 98.12 in comparison to the standard antibiotics tested. NDG showed better results in both MCF-7 and Hela cell lines with an IC\({}_{50}\) of 27.15 \(\upmu\)g/mL and 30.85 \(\upmu\)g/mL, respectively. The NDG revealed antibacterial activity against a wide range of pathogenic bacteria and also anticancer and biofilm inhibition activity, which recognized their applications in biomedicine.  
Conceptualization, A.A. and R.S.; methodology, A.M. and R.S.; software, A.A., A.M. and R.S.; validation, A.A. and R.S.; formal analysis, F.M.A., M.S.A., A.L.A., M.S., R.A., S.F.A., M.K. ([PERSON]) and M.K. ([PERSON]); investigation, M.K. ([PERSON]), R.S. and M.R.S.; resources, S.F.A. and R.S.; data curation, M.R.S. and R.S.; writing--original draft preparation, A.A., M.R.S. and R.S.; writing--review and editing, A.A., M.R.S., and R.S.; visualization, R.S., S.F.A. and M.K. ([PERSON]); supervision, A.A. and R.S.; project administration, A.A. and R.S.; funding acquisition, A.A. All authors have read and agreed to the published version of the manuscript.  
This research was funded by King Saud University, Riyadh, Saudi Arabia, Researchers Supporting Project number (RSP2022/R506).  
Not applicable.  
The authors extend their appreciation to the Researchers Supporting Project number (RSP2022/R506), King Saud University, Riyadh, Saudi Arabia for funding this work.  
The authors declare no conflict of interest.