Spectroscopic Study of Phytosynthesized Ag Nanoparticles and Their Activity as SERS Substrate
, Oleksandr Smirnov 3,4, Mariia Kovalenko 3, Nazar Mazur 1, Oleksandr Hreshchuk 1, Nataliya Taran 3, Svitlana Plokhovska 5, Yaroslav Pirko 5, Alla Yemets 5, Volodymyr Yukhymchuk 1 and Dietrich R. T. Zahn 6,7
Round 1
Reviewer 1 Report
The study "Spectroscopic study of phytosynthesized Ag nanoparticles and their activity as SERS substrate" describes the studies performed on Ag nanoparticles obtained by photo-reduction in the presence of solutions obtained from common toothwort (L. squamaria) and
pepper (Capsicum annuum and Capsicum chinense). These studies were aimed at determining the ligands protecting nanoparticles and their interaction with silver. SERS measurements were also made for rhodamine 6G, crystal violet, and malachite green. They showed that the protecting ligands had little effect on the SERS spectra.
The work is very well written, the literature is well chosen. The processing of the FTIR results deserves special praise.
Errors and Comments:
references to a bibliography sometimes is written in superscript
[76] maybe it is better to use the term "heated" instead of "boiled".
[128] for what “NC” stands for?
[191 - 192] Figure s2 is a FTIR spectra and Figure 1 is a UV-Vis spectra. I understand why shape of spectra in s2 can be a reason to show only one UV-Vis but it should be noted.
[317] reference to a bibliography is orange
The work requires only minor adjustments
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript “Spectroscopic study of phytosynthesized Ag nanoparticles and their activity as SERS substrate” discussed affordable and scalable synthesis of silver nanoparticles, provided characterizations of the formation of Ag nanoparticles and possible interactions, and demonstrated potential applications in SERS enhancement. The work is interesting with detailed analysis. However, a few things are needed to be addressed.
- The scientific writing quality needs to be much improved. For example, the abstract and introduction were so not specific. In the abstract, the author wrote " From FTIR and XPS we draw conclusions about the composition of the functional groups and molecules..". The author should specify the key findings in the abstract instead of not being specific. For the introduction too, the author wrote ...NPs can serve as a proper biofunctionalization for a certain application...". What are the applications? The writing is just not scientific. Due to that, the manuscript lack a well described background and significance.
- The work itself lacks significance. The key point the author tried to promote was the application of the Ag NP in SERS. For that experiment, the author selected a few dyes and an antibody. The selection seemed random, because they are not discussed in the introduction. The significance of this work is not clear of how this NP will improve the application in SERS in what field?
- Similar topic has been extensively presented by other people doing phytosynthesized Ag nanoparticles and their applications in SERS. The results of SERS enhancement was noticeable but not impressive. There was a weak guidance for potential applications of these Ag nanoparticles.
- It is not proper to include Table 1 as one of the major figures/tables in the manuscript. Most of the results are from citations in Table 1. It will be better included in supplementary.
In conclusion, I would recommend the author do a major revision of the manuscript, especially of the scientific writing.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Reviewer 3 Report
This manuscript by Dzhagan et al. reports on Ag nanoparticle (AgNP) SERS substrates prepared by phytosynthesis. The authors synthesized AgNPs in water with plant extracts of common toothwort or pepper. SERS activity of the phytosynthesized nanoparticles was shown to be comparable to those of citrate AgNPs, and sensitive enough to detect several analytes including E. coli antibody.
The work is well-organized and can be a good contribution to the field of sensors. I only have minor comments before the paper can be accepted for publication in chemosensors.
- It is important to see how many samples showed the good SERS efficiency to know the reliability of the phytosynthesis approach.
- Only SERS performance of the squamaria-derived AgNPs were presented in Fig. 5. It may be interesting to show and compare the same sets of data for the Carolina reaper counter parts.
- Shape and size distributions of the squamaria- and Carolina reaper-derived AgNPs can be measured to check whether there is any effect of the morphologies on the SERS efficiency.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have addressed the first round comments. I have no more comments. Hopefully, the author can continue working on this and provide extended applications of this subject.
