Gold Nanostars in Biology and Medicine: Understanding Physicochemical Properties to Broaden Applicability

Over the past few years, gold nanostars have gained significant relevance in biology and medicine, in particular, in imaging and photothermal therapy, also owing to their biocompatibility. Furthermore, they have improved the sensitivity of diagnostic assays and have been integrated in lab-on-chip platforms for low-cost, field-deployable devices. However, despite their widespread use, they have not found applicability beyond the research laboratories. One of the main reasons for this limitation has been the almost exclusive focus, until recently, on applications alone and not on the understanding of the fundamental properties of these particles, which has hampered reproducibility, stability, and overall reliability. Recently, however, a resurgence in the fundamental research of gold nanostars has dramatically improved our understanding of their synthesis, functionalization, properties, and thus their applicability. In this Perspective, the literature exploring and improving our knowledge of the physicochemical properties of gold nanostars is critically presented and framed within the specific context of biological and clinical applications. Furthermore, on the basis of the most recently reported results, a path forward is proposed, aimed at enabling an effective integration of these particles in the clinic.