Nanoparticles can be easily produced in typical low-pressure plasmas, either by injecting reactive gases or by sputtering materials deposited on the electrodes. In these cases, a dense nanoparticle cloud is obtained and fills most of the plasma volume. As nanoparticles attach plasma free electrons, a huge nanoparticle density induces a strong disturbance of the plasma properties and stability. It can give rise to a wide variety of low-frequency instabilities and to the appearance of a void region, usually located in the plasma center, and characterized by an enhanced light emission. In this contribution, laser absorption and laser induced fluorescence are used to evidence the effects of nanoparticle growth on argon metastable atoms. These non-intrusive laser techniques have recently shown their ability to reveal the strong plasma modification as nanoparticles are grown thanks to acetylene addition. In the present work, nanoparticles are grown from the sputtering of a carbonaceous layer deposited on the electrodes. The obtained dense nanoparticle cloud can be easily observed with laser light scattering. Absorption and fluorescence profiles are analyzed with a particular attention on spatially dependent effects related to void formation and nanoparticle cloud instabilities.