The interaction between fibroin and silver nanoparticles (AgNPs) paves the way for the development of hybrid materials with high-performance antimicrobial, mechanical, and electronic properties. Silver, known for its bactericidal activity at both ionic and nanoparticulate levels, can be effectively stabilized within the protein matrix thanks to the functional groups of fibroin, which promote coordinative bonding and a uniform dispersion of particles. This enables the creation of smart coatings for biomedical applications, where the active surface can selectively respond to bacterial contamination or biofilm formation. The optical and conductive properties of AgNPs are further enhanced by the fibroin structure, which serves as a three-dimensional scaffold for optical or piezoresistive sensors, ensuring rapid response and high sensitivity. These materials prove essential in the design of flexible, biodegradable, and multifunctional devices for e-health and diagnostics.
Plasmonic platforms and next-generation optical biosensing
Gold nanoparticles (AuNPs) represent a technologically strategic option in the development of optical sensors based on surface plasmon resonance (SPR). Fibroin allows the AuNPs to be organized in a stable and orderly fashion, preventing aggregation phenomena that would compromise their optical activity. In this context, the protein acts as a transparent and biocompatible matrix supporting plasmonic resonance while enabling chemical functionalization for the selective recognition of target molecules. Biosensors based on this combination can detect biomarkers, toxins, or viruses at extremely low concentrations, with applications in medical, environmental, and food sectors. The architecture of the fibroin-AuNPs composite also allows for the integration of additional functionalities, such as fluorescence or thermal response, making these systems adaptable to various portable diagnostic platforms.
TiO? and fibroin: photoactive devices and platforms for environmental electronics
The incorporation of titanium dioxide (TiO?) into fibroin enables the creation of nanostructured materials that are photocatalytic, dielectric, and UV-sensitive. TiO?, being a wide-bandgap semiconductor, can interact with fibroin to form a composite material capable of responding to both light and chemical stimuli. This type of hybridization is particularly effective in the development of environmental sensors, air or water purification systems, and biodegradable optoelectronic devices. The dielectric and photoreactive properties of TiO? are enhanced by the ordered and tunable interface of fibroin, which serves as an organic substrate for the controlled growth of nanoparticles. The result is a multiphase material combining transparency, flexibility, and photoactivity, ready to be integrated into next-generation architectures for environmental monitoring or sustainable electronics.
Flexible biosensing and biodegradable devices
The use of fibroin in combination with metallic and oxide nanoparticles enables the development of flexible, wearable, and even implantable biosensors capable of real-time physiological monitoring. The structure of fibroin, easily processable into thin films or three-dimensional microstructures, can host nanoparticles functionalized with enzymes or sensitive molecules, leading to multifunctional, high-resolution devices. Integration with AgNPs or AuNPs allows for the generation of electrical or optical signals in the presence of specific analytes, such as glucose, lactic acid, or electrolytes, while TiO? can be exploited for responsiveness to environmental stimuli like light or humidity. The controlled biodegradability of fibroin makes these sensors particularly suitable for transient medical applications, where the device dissolves after use, eliminating the need for surgical removal and reducing clinical risks and costs.
Fibroin and flexible electronics
In the field of flexible electronics, fibroin stands out as a natural substrate with excellent mechanical and optical performance, ideal for integrating conductive circuits and active components. When enriched with conductive nanoparticles such as gold or silver, fibroin can be used for printing high-resolution flexible circuits, while maintaining lightweight, transparent, and adaptable characteristics suitable for human-body interfaces. These devices find applications in smart textiles, biometric patches, wireless sensing systems, and direct human-machine interfaces. The contribution of TiO? adds new capabilities, including photovoltaic and memory functions, enabling the development of organic transistors, memristors, and self-powered energy systems. This type of electronics, both sustainable and biologically compatible, represents one of the most promising directions in the transition toward next-generation wearable and environmental technologies.
