Exploring the non (low)-toxic antibacterial/bactericidal materials which can prevent the growth of bacteria/kill bacteria is the subject of many recent works. Glasses and nanomaterials are novel agents in this field and in bio-imaging when employing the luminescent agents. In this chapter, some VI-element based materials containing transition metals (such as silver or sliver-free telluro-vanadate glasses and glass ceramics, bare and doped ZnSe nanoparticles) are discussed to give more comprehension into their opto-biological features and capabilities. Besides the synthesis and fabrication methods, structural and optical properties such as the formation of desired phases, precise optical band gap and optical absorption edge are presented and discussed. Furthermore, their detected antibacterial/bactericidal potential employing serial dilution and/or agar disc-diffusion bioassays are presented and discussed. The results emphasized the high antibacterial/bactericidal potential of the 30%-sliver containing glasses and glass–ceramics against the studied bacteria from both Gram-negative and Gram-positive categories. Moreover, in the cases of zinc selenide nanoparticles synthesized under various conditions, luminescence and antibacterial potential were evaluated as aspects dependent on dopant content and particle size. Such mentioned materials are promising agents in optical and biological applications. This chapter discusses these subjects, and gives sheds light on their applications in the bio-optical fields.