Five years after a sensational, love-gone-wrong attempted murder — in which one Manhattan psychiatrist allegedly ordered another Manhattan psychiatrist

bludgeoned to death with a sledgehammer

— the accused would-be killer has been thrown in jail.

Dr. Pamela Buchbinder pleaded not guilty Friday to the attempted murder of her ex-lover and fellow shrink Michael Weiss — and was ordered held without bail by a Manhattan Supreme Court judge.

“I’m innocent,” a thin, haggard-looking Buchbinder told reporters as detectives led her, handcuffed, through a public hallway and into the courtroom.

Prosecutors say Buchbinder manipulated her young, bipolar cousin, Jacob Nolan, into carrying out the intended hit, first marching the teen to the Home Depot in Chelsea to buy the sledgehammer.