Composite Structure of Ag Colloidal Particles and Au Sinusoidal Nanograting with Large-Scale Ultra-High Field Enhancement for SERS Detection

Round 1

Reviewer 1 Report

In this manuscript the authors discuss on a SERS platform designed and prepared by coupling Ag nanoparticles on a sinusoidal Au grating. The SPR generated by the grating can be used to enhance the LSPR on the Ag NPs and consequently enhancing the field confinement and the SERS signal.

the idea is nice, even if not new. The authors illustrate in a clear way the model reporting good simulations. Unfortunately the experimental part is very weak. no enhancement factor is evaluated and just 3 measurements at 3 different concentrations of the analyte are reported.

an improvement in the experimental part is needed in order to publish this paper.

The authors should also mention some previous examples of the use of Ag NPs on Au plasmonic platforms to enhance the SERS signal

in particular

J. Mater. Chem., 2010,20, 6891-6895

SPIE Conf. Proceeding 2017, 103460E

and

Biosensors and Bioelectronics 72, 2015, Pages 61-70

some minor errors:

line 90: Firstly, a positive photoresist (PR; NOA‐63) was first spin-coated on an SiO2 substrate. (first can be removed)

line 95: SRES

line 109: it is not clear why here they mention Ag grating...and no Au gratings....there are several works on Au sinusoidal grating for SPR

line 191: we not....

line 212: When the dimer is near AuSG, the hot spots not only in the nanogap of AgNPs, but also in the nanogap between dimer and AuSG.....something is wrong here with the grammar

line 216: single molecule??!?! it is an overstatement

Author Response

Dear Reviewer,

Thank you for your comments concerning our manuscript entitled “Composite Structure of Ag Colloidal Particles and Au Sinusoidal Nanograting with Large-scale Ultra-high Field Enhancement for SERS Detection”.These comments are all valuable and very helpful for revising and improving our paper, as well as an important guiding significance to our researches. We have studied comments carefully and have made correction. 

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In lines 206, 212, 228, and 230, carefully check whether it is AuNP or AgNP.

In lines 77-79, re-write “When an incident beam of light is focused on a metallic grating, the diffraction wave will be generated, which can directly couple to SPP if the momentum of the diffracted wave is matched with the grating surface[30].” It should be just momentum conservation.

Authors should provide a lot more details on controlling the distance between AgNP and AuSG.

Fig.2 shows the simulated reflection. This review is interested in experimental reflection data. What’s the dip wavelength?  Authors have been targeting 785 nm? Is there such a dip at 785 nm.

What kind of laser has been used for Raman scattering? Authors mentioned 785 nm. But details are missing.

Line 191, change “not” to “note”

Author Response

Dear Reviewer,

Thank you for your comments concerning our manuscript entitled “Composite Structure of Ag Colloidal Particles and Au Sinusoidal Nanograting with Large-scale Ultra-high Field Enhancement for SERS Detection”. These comments are all valuable and very helpful for revising and improving our paper, as well as an important guiding significance to our researches. We have studied comments carefully and have made correction. 

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

the authors have improved the manuscript accordingly to the referee's comments.

I recommend the publication

Reviewer 2 Report

I am OK with the revision.