If my daughters biological dad hasnt been in her life since i found out i was pregnant but my boyfriend has can he sign a voluntary DOP?

In order to change the last name of a minor, you would require a 'paternity action' (not a paternity test) to establish the biological father and address custody, visitation and support through the courts.  When filing for a name change for the child, the biological father would have to be served.  If he does not contest, the name change could go through. If you were to marry your boyfriend, he could file for a step-parent adoption and if the biological father agrees, the last name of the child could be changed within the adoption.