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Surface-enhanced Raman scattering (SERS) has already demonstrated its significant potential in analytical science. Thus, current efforts are focused on the development of affordable and reproducible SERS substrates, which exhibit high enhancement factors and uniform responses. A large number of strategies were adopted to produce effective SERS substrates; however, most of them are tuned for the use of single excitation wavelength and consequently can only be applied for a limited number of analytes. Hence, SERS substrates that demonstrate broadband plasmonic properties represent a more flexible analytical tool for multi-wavelength or tunable light sources, especially for biological applications. In the current study, we demonstrate that direct laser writing (DLW), which activates a photoreactive moiety and immobilizes functionalized gold nanoparticles on chemically modified glass substrates, can be used to produce SERS substrates of various sizes and geometries. We show that by tuning the DLW parameters a broad plasmonic response is obtained, enabling the use of these substrates for multi-wavelength SERS analysis. Two Raman reporters, a small synthetic benzotriazole azo organic dye and a larger biological molecule, hemin, are tested at three fixed excitation wavelengths in the visible range (473 nm, 532 nm and 660 nm). SERS enhancement factors show a weak dependence on the wavelength used and the molecules investigated; moreover, the possibility of creating arbitrary shaped and uniform structures is demonstrated. The reported results show that DLW is an excellent technique to engineer microstructured and broadband SERS substrates. © 2016 The Royal Society of Chemistry.

A photochemical approach based on nitrile imine-mediated tetrazole-ene cycloaddition is introduced to functionalize gold nanorods with biomolecules. For this purpose, a bifunctional, photoreactive linker containing thioctic acid as the Au anchoring group and a tetrazole moiety for the light-induced reaction with maleimide-capped DNA was prepared. The tetrazole-based reaction on the nanoparticles' surface results in a fluorescent pyrazoline product allowing for the spectroscopic monitoring of the reaction. This first example of nitrile imine-mediated tetrazole-ene cycloaddition (NITEC)-mediated biofunctionalization of Au nanorods paves the way for the attachment of sensitive biomolecules, such as antibodies and other proteins, under mild conditions and expands the toolbox for the tailoring of nanomaterials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoreactive gold nanoparticles (NP) can be encoded in a spatially resolved fashion using direct laser writing techniques into variable patterns. The surface of the gold nanoparticles is imparted with photoreactivity by tethering photo-caged dienes ('photoenols'), which are able to undergo a rapid Diels-Alder cycloaddition with surface anchored enes. Subsequent to surface encoding, the particles feature residual caged dienes, which can be reactivated for secondary surface encoding. This journal is © The Royal Society of Chemistry 2015.

A mild, efficient and ambient temperature photochemical approach for the synthesis of silver nanoparticle core-shell structures employing a zwitterionic polymer as well as polyethylene glycol is presented. This journal is © the Partner Organisations 2014.

DNA was modified with a photo-reactive caged diene allowing for the modification of dienophile containing proteins under mild irradiation conditions to afford fully functional DNA-protein conjugates. © 2013 The Royal Society of Chemistry.