This review presents an exhaustive and in-depth description of inorganic nanoparticle biosynthesis from photosynthetic organisms, known mechanisms and bio-applications.

Several methodologies have been devised for the design of nanomaterials. The “Holy Grail” for materials scientists is the cost-effective, eco-friendly synthesis of nanomaterials with controlled sizes, shapes and compositions, as these features confer to the as-produced nanocrystals unique properties making them appropriate candidates for valuable bio-applications. The present review summarizes published data regarding the production of nanomaterials with special features via sustainable methodologies based on the utilization of natural bioresources. The richness of the latter, the diversity of the routes adopted and the tuned experimental parameters have led to the fabrication of nanomaterials belonging to different chemical families with appropriate compositions and displaying interesting sizes and shapes. It is expected that these outstanding findings will encourage researchers and attract newcomers to continue and extend the exploration of possibilities offered by nature and the design of innovative and safer methodologies towards the synthesis of unique nanomaterials, possessing desired features and exhibiting valuable properties that can be exploited in a profusion of fields.

Microalgae are microorganisms of choice in biotechnology thanks to their wide range of potential bio-applications, such as over-expression of pigments, bioremediation, biofuel production and toxicity studies. Recently, microalgae have been gaining attention from materials scientists worldwide owing to their versatility, and the ease and the variety of procedures through which the biosynthesis of valuable nanomaterials is implemented. This has resulted mainly in the production of nanoparticles made of noble metals, alloys, oxides and chalcogenides. Although still burgeoning, the biosynthesis of nanomaterials based on the exploitation of microalgal resources may thrive and witness dramatic developments in the near future.

International audiencePoly(oligoethylene glycol methacrylate), POEGMA, brushes were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) on gold-coated silicon wafers. Prior to ATRP, the substrates were grafted by brominated aryl initiators via the electrochemical reduction of a noncommercial parent diazonium salt of the formula BF4-, N-+(2)-C6H4-CH(CH3)Br. The diazonium-modified gold plates (Au-Br) served as macroinitiators for ATRP of OEGMA which resulted in hydrophilic surfaces (Au-POEGMA) that could be used for two distinct objectives: (i) resistance to fouling by Salmonella Typhimurium; (ii) specific recognition of the same bacteria provided that the POEGMA grafts are activated by anti-Salmonella. The Au-POEGMA plates were characterized by XPS, polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS) and contact angle measurements. Both Beer-Lambert equation and Tougaard's QUASES software indicated a POEGMA thickness that exceeds the critical similar to 10 nm value necessary for obtaining a hydrophilic polymer with effective resistance to cell adhesion. The Au-POEGMA slides were further activated by trichlorotriazine (TCT) in order to covalently bind anti-Salmonella antibodies (AS). The antibody-modified Au-POEGMA specimens were found to specifically attach Salmonella Typhimurium bacteria. This work is another example of the diazonium salt/ATRP process to provide biomedical polymer surfaces