Smart Healthcare Photonic Nanomaterials and Devices

Abstract

Over the last decade, significant progress has been made in the fundamental principles, design, and synthesis of photonic nanomaterials with diverse optical properties and functionalities.[1-3] Light-emitting and light-responsive nanomaterials – such as semiconductor quantum dots, plasmonic metal nanoparticles, organic carbon, and polymeric nanomaterials – have enabled effective diagnostic, therapeutic, and theranostic applications including fluorescence imaging, plasmon resonance-based sensing and imaging, photoacoustic imaging, photobiomodulation, photothermal therapy, photodynamic therapy, and optogenetic therapy.[3] Among them, gold nanomaterials, carbon nanomaterials, polymeric melanoidin, and upconversion nanoparticles (UCNPs) have attracted particular attention due to their unique photonic properties and biocompatibility. On top of that, with the development of advanced micro-light emitting diodes (μ-LEDs), stretchable and flexible electronics, and wireless communication systems, wearable and implantable photonic devices have been extensively investigated for a variety of biomedical applications.[3, 4] These photonic devices capable of emitting specific wavelengths and controlling the intensity or frequency of emitted light have been especially useful for multifunctional applications, including optogenetics, wound healing, and cancer therapy. Furthermore, the structural designs of photonic devices have enabled conformal contacts with a minimized mechanical modulus, facilitating efficient light transfer for electrotherapy, such as nerve and bone regeneration, wound therapy and pain management.[5] Recent work has begun to translate some of these promising photonic nanomaterials into the clinic, along with wearable and implantable devices. In this Special Issue, we provide an overview for the current state-of-the-art research on emerging photonic nanomaterials and devices for various smart healthcare applications (Figure 1). This Special Issue comprises 17 articles (9 Reviews, 7 Research Articles, and 1 Perspective), and the collection highlights photonic nanomaterials for 1) diagnostic and therapeutic applications, 2) wearable healthcare devices, 3) implantable healthcare devices, and 4) cross-cutting digital healthcare applications. Finally, we discuss the opportunities and challenges for advancing these technologies toward the future of photomedicine. Recent advances in photonic nanomaterials have revolutionized the field of biomedical diagnosis and therapy, providing unprecedented opportunities for non-invasive, high-precision, and multifunctional interventions. This section highlights two timely reviews on emerging trends and three recent research articles introducing biocompatible photonic nanomaterial platforms with excellent feasibility for clinical translation. L. N. Liu, J. Chao, and co-workers (article number 2500086) provide a comprehensive review illustrating the power of DNA-directed assembly to construct photonic nanostructures with programmable precision. By harnessing sequence-specific hybridization, diverse optical building blocks such as plasmonic nanoparticles, fluorescent probes, and photonic crystals can be spatially organized into highly ordered architectures. Such DNA-based assembly provides not only structural tunability but also functional adaptability for biosensing, imaging, and theranostic applications. S. Sánchez, D. Esporrín-Ubieto, and co-workers (article number 2502171) focus on engineered plasmonic and fluorescent nanomaterials, particularly gold nanoparticles (AuNPs) and gold nanoclusters (AuNCs). AuNPs provide localized surface plasmon resonance for enhanced biosensing and photothermal therapy, whereas ultrasmall AuNCs (< 2 nm) exhibit size-dependent fluorescence and reactive oxygen species modulation. This article highlights the versatility of gold-based nanomaterials as theranostic agents, which bridge the gap between molecular imaging and therapeutic functions. Together, these reviews