This article reports a surface modification of gold nanoparticles with water soluble polyoxometalate, V10O286-(decavanadate, V10). Two sizes of citrate-capped gold nanoparticles AuNP-Citrate-S (similar to 11 nm) and AuNP-Citrate-L (similar to 46 nm) were modified with V10 in aqueous media to form AuNP-V10-S and AuNP-V10-L, respectively. Both AuNP-V10-S and AuNP-V10-L were found to be significantly better than their citrate counterparts in strengthening Raman vibrational signals of analyte molecule. All the nanoparticles were characterized by UV-visible and Fourier transform infrared (FTIR) spectroscopies, dynamic light scattering (DLS), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) line analysis. We demonstrate that AuNP-V10-L is excellent surface-enhanced Raman scattering (SERS) substrate for a Raman-active analyte molecule at nanomolar concentrations. (C) 2016 Elsevier Inc. All rights reserved.