How to unroot your android smartphone
1. Open superSU app and select “settings” tab & scroll to end where you will see “full unroot” option.
2. When you will select full unroot, a popup will appear if you want to unroot, you should tap on continue.
3. After that one more popup will appear and it will ask you if you to restore stock recovery image, you should select “NO”. if you select yes there are chances that it will download wrong recovery that may brick your phone.
4. and your phone should restart now and root has been removed.