Microcrystals of 1,4-bis(terpyridine-4'-yl)benzene (BTB) adsorb gold nanoparticles (AuNPs) with an average size of 15 nm or 25 nm from the solution forming an organic-gold composite with similar to 20 wt% of Au. The composite with 15 nm nanoparticles was characterized by thermal gravimetric analysis (TGA), transition electron microscopy (TEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Gold nanoparticles are uniformly distributed on the organic surface and retain the same size and shape distribution even after heating at 600 degrees C which removes the organic matrix of 1,4-bis(terpyridine-4'-yl)benzene and effectively deposits nanoparticles onto solid substrate (mica). The catalytic activity of composites was demonstrated using a model reaction of the reduction of 4nitrophenol to 4-aminophenol. The values of the apparent rate constants at 295K, ca. 1.9 x 10(-3) s(-1) for the Au(15 nm)-BTB and 7.2 x 10(-4) s(-1) for the Au( 25 nm)-BTB, obtained using UV-vis spectroscopy, are comparable to those reported for other catalytic systems based on supported Au nanoparticles. The catalytic activity is found to be size-dependent; the bigger nanoparticles show lower activity and longer reaction induction period. Au-BTB catalyst can be recovered from the reaction mixture and used again. (C) 2014 Elsevier B.V. All rights reserved.