A virus-based nanoplasmonic structure as a surface-enhanced Raman biosensor

Abstract

Fabrication of nanoscale structures with localized surface plasmons allows for substantial increase in sensitivity of chem/bio sensors. The main challenge for realizing complex nanoplasmonic structures in solution is the high level of precision required at the nanoscale to position metal nanoparticles in 3D. In this study, we report a virus-like particle (VLP) for building a 3D plasmonic nanostructure in solution in which gold nanoparticles are precisely positioned on the VLP by directed self-assembly techniques. These structures allow for concentration of electromagnetic fields in the desired locations between the gold nanoparticles or "hot spots". We measure the efficiency of the optical field spatial concentration for the first time, which results in a ten-fold enhancement of the capsid Raman peaks. Our experimental results agree with our 3D finite element simulations. Furthermore, we demonstrate as a proof-of-principle that the plasmonic nanostructures can be utilized in DNA detection down to 0.25 ng/μl (lowest concentration tested), while the protein peaks from the interior of the nanoplasmonic structures, potentially, can serve as an internal tracer for the biosensors.

Crystal Structure and Proteomics Analysis of Empty Virus-like Particles of Cowpea Mosaic Virus

“…More recently, these applications have turned to using eVLPs rather than the infectious virus (Lebedev et al, 2016; Sainsbury et al, 2011, 2014; Wen et al, 2012). Therefore, it is of importance to structurally characterize eVLPs and analyze any significant differences that occur between the wild-type virus and eVLPs of CPMV.…”

“…These can be generated by co-expression of the CP precursor VP60 along with the 24K viral proteinase in Nicotiana benthamiana (Montague et al, 2011; Saunders et al, 2009). CPMV eVLPs generated this way have already proven useful as reagents for bio- and nanotechnology applications (Lebedev et al, 2016; Sainsbury et al, 2011, 2014; Wen et al, 2012). …”

Recent Progress in Plasmonic Biosensing Schemes for Virus Detection

“…The sensing scheme of SERS benefits from the enhancement of Raman scattering by providing the modulation of surface plasmon polaritons at a greater distance from the metallic nanoparticle surface, thereby offering higher sensitivity than that of SPR and LSPR. Lebedev et al reported a SERS platform applied to the detection of viral DNA using nanoclusters (NC) of gold nanoparticles [ 44 ]. SERS experiments were performed on lone gold nanoparticles, individual nanoclusters, and in two distinct plasmonic nanoclusters.…”

Plant Virus Expression Vectors: A Powerhouse for Global Health

“…The genome of CPMV is bipartite, with RNA-2 being the principal component of expression vector development. CPMV has been utilized extensively in antigenic presentation and full-length protein expression as part of a fusion protein that can undergo proteolytic cleavage to release the therapeutic protein, as well as in material science research, such as the formation of magnetic clusters and biosensors [ 63 , 64 , 65 , 66 ]. For example, Medicago, Inc. (Durham, NC, USA) has used the CPMV vector to generate virus-like particles (VLPs) carrying influenza virus HA antigens [ 67 ].…”