**4. Conclusion**

Regarding the use AgNPs in heterogeneous photocatalysis, it can be proved highly efficient in the degradation a large amount of organic pollutants and inactivation of bacteria and pathogens, under either UV radiation or visible light. Moreover, when supported AgNPs-based nanophotocatalysts are used in wastewater not only the photocatalytic activity is enhanced, but also some operational problems (nanoparticles agglomeration) can be fixed. With respect to the use of AgNPs as antimicrobial agents, it is a current alternative against common pathogens and multi-resistant bacteria due to the toxicity to microorganisms compared to antibiotics and conventional approaches. In addition, AgNPs-based biosensors are resulting in high sensitivity and selectivity aligned to wide detection limits, which turns them suitable for clinical practice. It is worth to point out that the green synthesis of AgNPs is increasing along the years, and when combined with photocatalytic and biomedical applications, contributes to sustainable development and biocompatibility aspects.
