No officer or employee shall receive, directly or indirectly, any other compensation for his or her services than that provided by law, or by the commissioner before his or her appointment, nor shall he or she receive any compensation whatever, directly or indirectly, for any act or service which he or she may do or perform for or on behalf of any contractor, or agent, or employee of a contractor. For any violation of this section the officer, agent, or employee of the state engaged therein shall be dismissed from his or her office or service, and every contractor, or employee, or agent of a contractor, engaged therein shall be expelled from the grounds of an institution, and not again employed in any institution as a contractor, agent, or employee.