Particulate main-group elements (As0, Sb0, Bi0, Pb0, Se0, Te0) and compounds (Bi4Te3, Sb x Bi1–x with 0 ≤ x ≤ 1) are obtained via photoinitiated reduction under UV irradiation. The synthesis of Bi0 and Se0 is exemplarily studied in detail. Here, meso- to micrometer-scaled particles are obtained with mean diameters of 81(11) nm (Bi0) and 1.15(18) μm (Se0) in the absence of specific stabilizers that allow controlling the particle growth. In contrast, the particle diameter is significantly reduced in the presence of specific stabilizers (e.g., polyvinylpyrrolidone/PVP for Bi0, 2-mercaptoacetid acid/MAA for Se0). Now, even the nanoregime is reached with mean diameters of 4(2) nm (Bi0) and 290(39) nm (Se0). The photochemical synthesis is easy to perform (i.e., aqueous solution/suspension, room temperature, conventional chlorides/oxides as starting materials) and leads to a homogeneous particle nucleation, only initiated by UV irradiation as an external physical trigger. The resulting particulate main group elements and compounds are characterized by electron microscopy (SEM), dynamic light scattering (DLS), X-ray powder diffraction (XRD), and energy-dispersive X-ray (EDX) analysis. The mechanism of the light-initiated reaction can be clarified by polymerization experiments to involve radicals as intermediate species.

Polymer‐based synthetic mimics of antimicrobial peptides (SMAMPs) show promising antimicrobial activity in solution and as surface‐attached networks. In this paper, their potential as active ingredients in layer‐by‐layer (LbL) assemblies is evaluated. These consist of the weak, anionic polyelectrolyte poly(acrylic acid), and either the hydrophobic butyl SMAMP or the hydrophilic diamine SMAMP (both of which are cationic, weak polyelectrolytes). In situ surface plasmon resonance spectroscopy is used to optimize the LbL assembly conditions. An “overshooting” is observed when depositing the SMAMP layer. Zeta potential measurements show that the layer charge inversion is reduced at each build‐up step due to layer interpenetration. Thus, the positive charge of LbL assemblies with SMAMPs as the top layer is low; a significant part is consumed to maintain layer stability. This leads to reduced antimicrobial activity. Fine‐tuning of the assembly and post‐treatment conditions leads to SMAMP‐PAA LbL systems with optimized antimicrobial activity and stability.