Self-assembled colloidal gold nanoparticles as substrates for plasmon enhanced fluorescence

Abstract

Decades of intense research in the field of nanoscience have led to the ability to produce nanoparticles (NPs) with controlled composition, shape, and size. One of the next key challenges is the self-­assembly of appropriate NP building blocks into larger systems to obtain microscale or macroscale materials. To achieve this, self-assembly protocols must not only produce high-quality structures but also deliver the assemblies of interest to desired locations on a substrate. In this review, we discuss different self-assembly strategies, focusing on colloidal gold NPs and applications as plasmon-enhanced fluorescence (PEF) platforms. These plasmonic substrates have been used for biosensing and cell imaging, based on the enhancement of fluorescent emitters, and applied to improve the emission efficiency of luminescent NPs. It is important to note that higher fluorescence enhancement relies on precise control of the location of gold NPs and fluorescent emitters on the plasmonic substrate. Despite the diversity of available self-assembly strategies, many of them provide similar levels of structural control over the placement of gold NPs on the substrate. To highlight this, we have organized the discussion according to strategies that result in similar degrees of structural control over the placement of gold NPs and its associated PEF effect.

Graphical abstract

Keywords:

• Self-assembly on a substrate
• plasmon enhanced fluorescence
• gold nanoparticles
• surface plasmons

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 861950, project POSEIDON. Oscar F. Silvestre acknowledges the support from the Provincial Council of Gipuzkoa under the program Fellows Gipuzkoa.

Notes on contributors

Oscar F. Silvestre

Oscar F. Silvestre completed his PhD in 2011 at Cardiff University, UK. He joined in 2012 the NIBIB-National Institutes of Health as an AXA Research Fund postdoctoral fellow, to work on nanoparticle platforms for gene/drug therapy. He then obtained a Marie Curie COFUND postdoctoral fellowship in 2016 at INL – International Iberian Nanotechnology Laboratory, Portugal, expanding his research in nonlinear optical imaging for biosensing. In 2019, he became a Fellow Gipuzkoa at CIC biomaGUNE, Spain, where he gained expertise in the synthesis of colloidal gold nanoparticles, plasmon enhanced fluorescence and their biological applications.

Anish Rao

Anish Rao completed his B.Sc. with honours in chemistry in 2013 at Ramjas College in Delhi University (India). He then obtained his MS + PhD (in 2020) from Indian Institute of Science Education and Research (IISER) Pune, India. He worked under the supervision of Dr. Pramod P. Pillai on regulating interparticle interactions for nanoparticle self-assembly with increasing degree of complexity. He then moved to a postdoctoral position on the development of multicomponent nanoparticle self-assemblies for applications in photonic integrated circuits, with Prof. Luis M. Liz-Marzán at CIC biomaGUNE, Spain. He is presently working as a Juan de la Cierva fellow at Centro de Física de Materiales (CSIC-UPV/EHU), Spain.

Luis M. Liz-Marzán

Luis M. Liz-Marzán is an Ikerbasque Professor at CIC biomaGUNE (BRTA), in San Sebastián (Spain), where he also served as Scientific Director from 2012 to 2020. Luis graduated in chemistry from the University of Santiago de Compostela, was postdoc at Utrecht University and Professor at the University of Vigo (1995–2012), where he currently holds a part-time Professor position. Luis has been visiting professor at various research institutions worldwide and received numerous scientific awards and honors. He is also a member of the Spanish Royal Academy of Sciences, European Academy of Sciences and Academia Europaea. He currently serves as an executive editor at ACS Nano, and on the editorial advisory board of several journals including Science, Acc. Mater. Res. and Adv. Funct. Mater. Liz-Marzán is known for his work on the colloidal synthesis and self-assembly of metal nanocrystals, as well as the characterization and application of their plasmonic properties. More recently, his research has broadened into the biomedical applications of plasmonic nanostructures.