Molecularly imprinted hydrogels (MIHs) composed of N-isopropylacrylamide (NIPA) and maleic acid (MA) monomers and fibrinogen (Fbg, MW: 340 kDa, pl: 5.8) imprinted molecule were fabricated in pH buffer solutions (pH(prep): 4.0, 5.8 and 8.0). The non-imprinted hydrogels were also prepared in the same conditions without Fbg imprinted molecule. The adsorption equilibrium constant and the maximum adsorption capacity of the MIH prepared in pH 4.0 were evaluated to 9.61 mL mg(-1) and 38.99 mg protein g(-1) dry gel in pH 4.0 buffer solution, respectively. The selectivity tests were also performed by using two reference molecules as bovine serum albumin (BSA, MW: 67 kDa, pl: 4.78) and urease (MW: 480 kDa, pl: 5.99). The MIHs have 2.37-4.23 times higher selectivity for the Fbg imprinted molecule than the non-imprinted hydrogels prepared in the same conditions. Easy preparation of the MIHs, their high stability and ability to recognize small and large proteins, as well as to discriminate molecules with small variations in charge, make this approach attractive and broadly applicable in biotechnology, assays and sensors. (C) 2009 Elsevier Ltd. All rights reserved.