The significant rise in implementation and applications of plasmonic nanosystems in biophysics, biochemistry, and medicine has culminated in the emergence of refined plasmonic enabling reagents, or “nanoagents”. These are defined as tools that allow researchers to not only investigate, but also actively manipulate biological processes and complex biosystems, such as living cells, on the nanoscale. This development is based on a combination of sensing capabilities, photothermal control, and optical force manipulation offered by metallic nanoparticles. The article reviews the trajectory that plasmonic nanoagents have taken in recent years and highlights seminal recent examples of their application, such as optical sensing both in vitro and in vivo, optical control of biomolecular interactions and protein function, the manipulation of lipid membrane properties, and the possibility of guiding cellular behavior.Fil: Huergo, María Ana Cristina. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Schuknecht, Francis. Ludwig Maximilians Universitat; AlemaniaFil: Zhang, Jinhua. Ludwig Maximilians Universitat; AlemaniaFil: Lohmüller, Theobald. Ludwig Maximilians Universitat; Alemania