Microbial contaminants represented by harmful bacteria and viruses are dangerous to human health and outbreaks of diseases caused by the consumption of food and water contaminated with such pollutants have drastically increased in recent years. In order to prevent disease outbreaks, there is an urgent need to develop cost-effective strategies with fast response time and high portability for real-time detection, identification, and monitorization of microbial contaminants. Spectroscopic techniques provide opportunities for such applications as they enable the selective detection of extremely low quantities of pathogenic contaminants in various environmental samples such as food, soil, drinking water, wastewater, aquatic ecosystems, etc. In this chapter, we review some recent progress related to analysis and monitoring of microbial pollutants by Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS), infrared spectroscopy (IR), surface-enhanced infrared absorption (SEIRA), fluorescence spectroscopy, localized surface plasmon resonance, and impedance spectroscopy. In particular, we highlight the advances in the fabrication of innovative nanostructured metallic platforms for ultrasensitive and selective detection of pathogens and simultaneous identification and discrimination of multiple contaminants in environmental samples.

One of the main priorities of the nanotechnology scientific community is the advancement of therapeutic approaches able to improve treatment outcomes with minimal side effects and elevate patient care. Nano-phototherapies such as nano-photodynamic (NanoPDT) and nano-photothermal therapy (NanoPTT) are proven to be excellent alternatives to conventional treatment strategies, especially when simultaneously applied. The current chapter aims to provide an extended overview of the most recent advances made in the development of hybrid nanosystems able to perform highly effective synergistic NanoPDT/PTT therapy. Outstanding therapeutic performances are reported for nanoparticle-based nanosystems of both plasmonic and nonplasmonic origin; thus their particularities and versatility as efficient dual NanoPDT/PTT nanoagents are addressed throughout this chapter, underscoring their promising potential in the treatment of a wide variety of medical conditions. Despite significant progress, further research is required to overcome the remaining challenges that delay the translation of these innovative therapies into clinical trials and, ultimately, clinical practice.

The survival of humankind and the Earth is closely linked to a “one health” vision of scientific and technological progress. Our health and the health of our planet are bound to find equilibria and interplay also involving cohabitation with pathogenic microorganisms. The need to control human and environmental health is strictly related to the availability of tools able to achieve the accurate, precise, and fast detection of pathogens, such as the biosensors. Noble metal nanoparticles can offer unique opportunities to develop high-performing and user-friendly biosensors for pathogen monitoring. This chapter describes how noble metal nanoparticles, due to their plasmonic properties, can be used as a powerful and unique toolbox for developing biosensors for pathogen detection, in different biosensing systems. Specific sections are dedicated to refractometric optical biosensors, surface-enhanced Raman scattering, and electrochemical biosensors. Moreover, attractive opportunities for biosensors on flexible substrates are provided. A visionary perspective on the future challenges in the field of plasmonic biosensing is provided in the conclusive section of the chapter.

A significant challenge in biomedicine is the inefficient delivery of drugs to the posterior segment of the eye. This study presents an innovative and minimally invasive approach for treating diabetic retinopathy, a complication of diabetes affecting the eye. We introduce novel near-infrared (NIR) light-responsive multifunctional microcapsules, which demonstrate a high loading efficiency of a NIR photothermally-active fluorophore (75%) and an even higher capability to bind the therapeutic drug Avastin on their surface. These polymeric multifunctional microcapsules, created using the Layer-by-Layer deposition technique, serve as microcarriers for targeted Avastin delivery to the retina, releasing the drug in vitro upon NIR laser exposure. The Avastin-targeted microsystem was thoroughly characterized in terms of morphology, phototherapeutic capacity, NIR-light stimulated drug release, and its potential as a fluorescent contrast agent for in vitro imaging. Re-Scanning Microscopy and Scanning Electron Microscopy revealed the formation of 4.5 ± 0.3 μm spherical microcapsules that maintained stability over seven months. The binding of Avastin to the microsystem’s surface was confirmed using various spectroscopic methods. The phototherapeutic potential of the microsystem in solution was initially assessed, followed by investigations into the shell rupture and subsequent drug release in vitro within human retina cells. The WST-1 assay demonstrated the biocompatibility of the microcapsules. Localization of the microcapsules inside human D407 retina cells was confirmed using Conventional Fluorescence Microscopy and 3D Re-scan Confocal Microscopy (RCM). Finally, the in vitro results validate the therapeutic potential of this multifunctional microsystem, demonstrating its effectiveness as a drug delivery and release system that could supplant conventional treatment strategies for diabetic retinopathy.

Environmental pollution becomes, with every passing year, one of the most serious problems because the environment is continuously exposed to multiple contamination sources coming from various industrial activities. Recent advances in the field of nanotechnology have provided genuine opportunities to develop and use novel cost-effective environmental purification technologies. Hybrid nanomaterials, based on polymer-coated plasmonic nanoparticles have received an increasing amount of interest for such applications thanks to their significant advantage of incorporating into the same system both the polymer characteristics and the physicochemical properties of plasmonic nanoparticles. In this chapter, we highlight progress in the fabrication of polymer-coated plasmonic nanoparticles with antibacterial, catalytic, or adsorptive properties for the removal, degradation, or the reduction of various contaminants, including bacterial pathogens, pesticides, organic dyes, and heavy metal ions.