As per the Review template reviewed the article

comment on Abstract, title and references

1.In abstract ,last sentence was magnetite can use in applications,Better to mention at least one of its application then it strengthens the paper. 2, In title repetitive words are observed like green and bio. 3. Author has to include some more references to support the mechanism with seaweed that was in figure 1B

Comment on Introduction/background

4,In introduction specific phytochemcals present in seaweed was not mentioned.

Comment on Methods

5 In experimental part written that seaweed extract was stored at -20 degrees . usually stored at -4 degrees which was not explained.

.Comment on Results and discussion

6(a). in Results and discussion it was interesting that usually FTIR spectroscopic results were found in between 400 cm- to 4000 cm- but it was from zero to 4000cm- ,

(b) XRD pattern was not compared with JCPDS file. (c)one more interesting was cubic crystal formation, but why cubic crystals are formed were not explained, (d) In UV visible absorption spectra that was in figure 6 indicated formation of nano particles observed at 402 nm and 415 nm ,If reference is quoted point will be worthy.Usually the peaks are around 360 nm.

Structure of my comments into a full review:

Overall statement

                     In the above published paper ,authors reported the synthesis of magnetite nano particles using aqueous extract of Sargassum muticum (seaweed) .This article showed evidences of magnetite by UV,FTIR,XRD ,SEM,TEM and VSM characrterization studies .Overall ,this paper was well written..However,it is necessary to clarify following minor issues to improve the quality of the published paper to meet the standards.

                     Repetitive words are written in title of the paper those are green and bio ,Hence reviewer suggest to modify the title as " Green synthesis of magnetite nano particles using Seaweed (Sargassum muticum ).
                        Abstract is clear but includes some more instrumental analysis (UV- drs, Xps...)and application,which added the significant strengthen to the paper.
                       All references are arranged with journal format but particular  phytochemicals of seaweed was not quoted.hence more references has to add to give importance to bio molecules of present  seaweed.
                       Authors have given good introduction about applications,synthesis of nano particles but general discussion was given to bio molecules of seaweed.

                        Results and discussion are interesting , usually FTIR spectroscopic results were found in between 400 cm- to 4000 cm- but it was from zero to 4000cm- ,  XRD pattern was not compared with JCPDS file.One more interesting was cubic crystal formation, but why cubic crystals are formed were not explained,
                      In UV visible absorption spectra that was in figure 6  indicated formation of nano particles observed at 402 nm and 415 nm this point will be worthy when reference is quoted.Usually the peaks are around 360 nm.
                  In experimental part written that seaweed extract was stored at -20 degrees . usually stored at -4 degrees which was not explained.

. In conclusion not mentioned the size and shape of the synthesized particles . There is no typographical mistakes which strengthens the article.and no evidence of sulphonated polysaccharides are main sources of Seaweed .