The affidavit said Hovey -- arrested two days before his 33rd birthday -- sent a letter to another Du Pont chemist in October offering to pay '$10,000 or more' if the chemist could put Hovey in contact with a drug dealer.
The letter gave specific instructions to the chemist to locate a drug dealer and for the dealer to communicate the Hovey through classified ads in the Wilmington (Del.) News Journal, the affidavit said.
Synthetic heroin has been blamed for about 100 deaths on the West Coast.
The affidavit by agent William Glanz of the Drug Enforcement Agency said the street price of one ounce of the drug is $28 million.
'I'm sure we'll have no trouble being completely straight with each other in all these transactions.