The commissioners shall execute a good and solvent bond, in an amount to be specified by the county legislative body, payable to the state, for the benefit of the county from which they were elected, conditioned that they will faithfully and impartially execute all the duties imposed upon them, without favor for any part of the county over that of any other part of the county; that they will honestly and faithfully expend and account for all moneys coming into their hands; and that they will as honestly and economically expend the money for the county as if it were their own private funds. The bond must be prepared, executed, filed, and recorded in accordance with title 8, chapter 19.