A 12-mer peptide with an affinity for the meso diad sequence of poly(N-isopropylacrylamide) (PNIPAM) was identified through affinity-based peptide screening. A model protein (i.e., human serum albumin (HSA)) chemically modified with the peptide was successfully precipitated with PNIPAM above the lower critical solution temperature (LCST) of PNIPAM.