How to prevent duplicate files in Subfolders – Laravel?

I created a add view where multiple files can be upload at same time :
View
The file path when file will be uploaded is like – Drawings/PartNumber/Type/filename.extension
How can I check in Drawing Folder any file cant not be same with extension like

1. Drawings/PartNumber1/Type1/filename1.pdf
2. Drawings/PartNumber2/Type2/filename1.pdf
3. Drawings/PartNumber1/Type3/filename1.pdf
4. Drawings/PartNumber1/filename1.pdf
5. Drawings/filename1.pdf
   never will be accepted.

My function is :

public function AddNewPart(Request $request)
    {
if (array_key_exists('DrawingFile',$data)) {
                foreach($request->file('DrawingFile') as $key=>$file)
                {
                    if ($data['fileupload_ID'][$key]==NULL) {
                        $extension=$file->getClientOriginalExtension();
                        $file_name2 = $file->getClientOriginalName();
                        $filepath='Drawings/'.$data['PartNumber'].'/'.$data['Type'][$key].'/'.$file_name2;
                        $file->move(public_path('Drawings/'.$data['PartNumber'].'/'.$data['Type'][$key].'/'), $file_name2);
                        $DocumentData2=array('Type'=>$data['Type'][$key],'fcontent'=>$file_name2,'condpartno'=>$data['PartNumber'],'fname'=>$filepath,
                        'DrawingNo'=>$data['DrawingNo'][$key],'DocumentType'=>$data['Type'][$key]);
                        DB::table('fileupload')->insert($DocumentData2);
                    }
                }
            }
    }