No. There are only two ways to ensure payment after discharge in bankruptcy: by bringing an adversary proceeding during the bankruptcy and obtaining a declaration either that the debt is non-dischargeable or that the debtor is not entitled to a discharge at all, or by executing and filing with the court a reaffirmation agreement. A pre-bankruptcy agreement not to discharge a particular debt is not enforceable. There are roughly 18 reasons why a debt might be non-dischargeable, and they are enumerated in section 523(a) of the Code. Interpreting any part of the very complex Bankruptcy Code is not a job for a lay person. If there is a substantial amount of money at stake here, you would be foolish not to discuss this matter with a skilled bankruptcy lawyer.
To add to what Mr. Oney said, unpaid wages are a priority claim, so in the event there are funds to be distributed, your claim would move toward the front of the line, ahead of general unsecured creditors.
Bankruptcy protection is a constitutional right and you can't contract it away. But, as other counsel pointed out even if a debtor files for bankruptcy protection certain debts are treated as non-dischargeable and/or priority debts and as such receive special treatment in bankruptcy.