A Methodology for Porcine Circovirus 2 (PCV-2) Quantification Based on Gold Nanoparticles
, Bruna L. Silva 1, Valber A. Pedrosa 3 and João P. Araújo Junior 1,2Round 1
Reviewer 1 Report
The authors claimed that "The current study introduced a new methodology for PCV-2 diagnosing in pig serological samples" in the abstract and in the conclusion part. This is not a new methodology, hence this part should be modified. Figure 6: AuNPs without surface modification showed an absorbance peak of 1.44 at 526 nm (black line)....... One cannot argue that Antigen-antibody binding to change the absorption intensity as it is relative. Please explain this. The shifting of the wavelength could be influenced by the agglomeration and heat-stress of AuNPs/protein binding. Discussion in this regard is necessary with appropriate references. Figure 5:TEM and EDX images generated for all AuNPs surface modification steps- EDX is not sensitive enough to detect DNA, FTIR should be performed to study this effect.The papers should be modified according to the above comments.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript describes quite interesting method. Unfortunately, the assay should be tested more extensively. The authors used positive and negative serum samples and validated the assay to standard PCR. However, interference were not tested. The fact that the assay does not provide false results with control samples does not mean that interference can not appear. There should be tested similar non-enveloped DNA viruses and/or DNA fragments to check whether they are not able to cause false positive signal. The risk of false positivity is crucial for any analytical method that is expected to be used for diseases diagnosis. Wrong diagnosis can be fatal and any new method should be tested in this regard.
There should be also tested limit of detection for the assay and it should be compared with expected concentration of the virus from literature. It should be tested and discussed whether there is a risk false negativity due to too high limit of detection.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The manuscript was improved significantly, I have no further comments.
