Biorthogonal sequence for monomials in L2(0,1)

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A sequence $(x_n^*)_{n \in \mathbb{N}}$ is a biorthogonal sequence for a sequence $(x_n)_{n\in\mathbb{N}}$ in a Hilbertspace $H$ if $$ (x_m^*, x_n) = \delta_{mn} $$ for all $m,n \in \mathbb{N}$. Does a biorthogonal sequence for the sequence of monomials exist in $L_2(0,1)$?