Numerical simulations of the multi-fluid equations are utilized to study the sheath structure in an acetylene plasma consists of electrons, different species of positive and negative ions, and charged nanosize dust particles. It is found that in the presence of negative ions spatially periodic fluctuations are developed in the profiles of the plasma and dust parameters. The fluctuations are enhanced with increasing the electronegativity, ion Mach number and neutral number density, while they are suppressed with increasing the dust Mach number. As the electronegativity increases, the incident dust flux on the wall decreases, whereas the positive ion flux increases. The sheath width is a descending function of the electronegativity, plasma number density, ion Mach number, and dust radius but increases monotonically with the neutral number density. (C) 2013 Elsevier B. V. All rights reserved.