If you are receiving interest in a current bank account, can the interest funds be used for good causes, without any intention of reward from Allah? Please throw some light on it.

I believe, ‘yes’. In fact, using those funds to help the needy or investing them in a noble cause, without expecting rewards in return, is the best possible attitude one can adopt. In today’s world, where interest is deeply ingrained in society, adopting a charitable attitude seems to be the best option, when it is not in one’s authority to change a system or to eliminate the evils within a system. Since consuming such an amount is obviously prohibited, the only legal venues for such funds seem to be the doors of the needy. So, please do continue in this direction, and as you very rightly point out, without granting it the status of earning reward from God, for that can only be a product of some form of income which is not prohibited.