Palladium supported on polypyrrole/reduced graphene oxide nanoparticles for simultaneous biosensing application of ascorbic acid, dopamine, and uric acid
Authors: Kemal Cellat
Buse Demirkan
Sait Bozkurt
Kubilay Arƒ±kan
Mehmet Salih Nas
Mustafa Yƒ±lmaz
Mehmet Hakkƒ± Alma
Mehmet Nuri Atalar
Aysun ≈ûavk
Mehmet Harbi √áalƒ±mlƒ±
Fatih Sen
Journal: Scientific Reports (2020)
Discipline: Multidisciplinary
Keywords: palladium nanoparticles; polypyrrole; reduced graphene oxide; electrochemical sensor; glassy carbon electrode
Affiliations: Sen Research Group, Department of Biochemistry, Faculty of Arts and Science, Dumlupinar University, Evliya √áelebi Campus, 43100, K√ºtahya, Turkey., Department of Environmental Engineering, Faculty of Engineering, University of Igdir, Igdir, Turkey., Sen Research Group, Department of Biochemistry, Faculty of Arts and Science, Dumlupinar University, Evliya √áelebi Campus, 43100, K√ºtahya, Turkey. .

Abstract:  In this study, we report a facile and effective production process of palladium nanoparticles supported on polypyrrole/reduced graphene oxide (rGO/Pd@PPy NPs). A novel electrochemical sensor was fabricated by incorporation of the prepared NPs onto glassy carbon electrode (GCE) for the simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The electrodes modified with rGO/Pd@PPy NPs were well decorated on the GCE and exhibited superior catalytic activity and conductivity for the detection of these molecules with higher current and oxidation peak intensities. Simultaneous detection of these molecules was achieved due to the high selectivity and sensitivity of rGO/Pd@PPy NPs. For each biomolecule, well-separated voltammetric peaks were obtained at the modified electrode in cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements. Additionally, the detection of these molecules was performed in blood serum samples with satisfying results. The detection limits and calibration curves for AA, DA, and UA were found to be 4.9 √ó 10-8, 5.6 √ó 10-8, 4.7 √ó 10-8 M (S/N = 3) and ranging from 1 √ó 10-3 to 1.5 √ó 10-2 M (in 0.1 M PBS, pH 3.0), respectively. Hereby, the fabricated rGO/Pd@PPy NPs can be used with high reproducibility, selectivity, and catalytic activity for the development of electrochemical applications for the simultaneous detection of these biomolecules. 

Retracted: No

PubPeer comments:
 Unexpected similarity in TEM image of nanoparticle (only zoomed part) with another paper https: pubpeer.com publications 6389B57905710C7A5B59C6673547D7#2 Histograms are also very similar with slightly different numbers.  , 
 Can authors explain so good reproducibility of relative size of their nanoparticles? Relative intensity of bars is exactly the same in 3 papers. Only size shifts little bit: https: pubpeer.com publications 6389B57905710C7A5B59C6673547D7#2 https: pubpeer.com publications 42991F07A3C2A2FD48078C4F40B70A  , 
 To add to Thallarcha Lechrioleuca s finding in comment #1, this paper is one of at least 30 papers by the same research group that all share the same photo. In all papers, this photo is used as a zoomed-in inset representing the high-resolution transmission electron microscopy (HRTEM) analysis of the  atomic lattice fringe and particle size of the nanoparticles. Of concern, the same photo is used to represent a different type of nanoparticle in each of these papers. Here is a collage of 6 different uses of the same photo,  Inset 1 :  Here is a list of the 30 papers identified so far that all use this photo, and the different types of nanoparticles that they represent. * Aysenur Aygun et al. - DOI: 10.1016 j.jpba.2019.112961 - Nigella sativa Pt * Aysun Su0327avk et al. - DOI: 10.1016 j.molliq.2019.112355 - PtNi@AC * Aysun Su0327avk et al. - DOI: 10.1016 j.msec.2019.01.113 - ZnNi@f-MWCNT * Aysun Su0327avk et al. - DOI: 10.1038 s41598-019-55746-y - PdNi@rGO * Betuu0308l Su0327en et al. - DOI: 10.1016 j.ijhydene.2018.03.175 - Pd@GO * Betuu0308l Su0327en et al. - DOI: 10.1016 j.nanoso.2017.08.013 - PdRu@GO * Betuu0308l Su0327en et al. - DOI: 10.1016 j.apcatb.2017.11.067 - RhPt TC@GO * Betuu0308l Su0327en et al. - DOI: 10.1016 j.ijhydene.2018.07.081 - Pd-Ir@AC * Betuu0308l Su0327en et al. - DOI: 10.1016 j.jcis.2018.05.021 - Ru-Ni@PVP * Betuu0308l Su0327en et al. - DOI: 10.1016 j.nanoso.2018.07.008 - Pd@AC * Betuu0308l Su0327en et al. - DOI: 10.1016 j.ijhydene.2018.07.122 - PdRuNi@GO * Betuu0308l Su0327en et al. - DOI: 10.1016 j.ijhydene.2019.01.215 - PdCo@GO * Betuu0308l Su0327en et al. - DOI: 10.1016 j.jtice.2019.04.040 - PdNi@VC * Betuu0308l Su0327en et al. - DOI: 10.1016 j.ijhydene.2018.12.051 - PdCo@MOF * Betuu0308l Su0327en et al. - DOI: 10.1016 j.ijhydene.2019.02.176 - RuCu@rGO * Birguu0308tay Su0327ahin et al. - DOI: 10.1016 j.colsurfb.2017.12.042 - Pt * Buse Demirkan et al. - DOI: 10.1038 s41598-020-59935-y - rGO Pd@PPy * Buse Demirkan et al. - DOI: 10.1038 s41598-019-48802-0 - Pt-Co@rGO * Fatma Diler et al. - DOI: 10.1016 j.molliq.2019.111967 - Pd@GO * Hayriye Genc Bilgicli et al. - DOI: 10.1016 j.micromeso.2020.110014 - CPG * Hilal Acidereli et al. - DOI: 10.1016 j.renene.2020.07.105 - PdRu@G * Mehmet Salih Nas et al. - DOI: 10.1016 j.molliq.2019.112100 - Pt-Co@GO * Nabih Lolak et al. - DOI: 10.1021 acsomega.9b00485 - PdNi@GO * Oznur Alptekin et al. - DOI: 10.1039 D0CY00641F - PtRh@GO * Rukiye Ayranci et al. - DOI: 10.1016 j.msec.2019.02.040 - Pt Ni@rGO * Sait Bozkurt et al. - DOI: 10.1016 j.aca.2017.07.051 - Pd TNM@rGO * Sinan Eris et al. - DOI: 10.1016 j.jcis.2017.11.085 - Pt@f-CB * Sinan Eris et al. - DOI: 10.1016 j.ijhydene.2017.11.063 - Pt@f-VC * Suat Tacu0327yu0131ldu0131z et al. - DOI: 10.1016 j.molliq.2019.04.019 - Ru-Rh@PVP * Zeynep Dasu0327delen et al. - DOI: 10.1016 j.apcatb.2017.08.014 - Pt@GO-PVP , 
 This paper is one of 5 so far found showing identical Pd XPS spectrum each time for different materials. Other appearances: https: doi.org 10.1038 s41598-019-55746-y https: pubpeer.com publications 6389B57905710C7A5B59C6673547D7 http: dx.doi.org 10.1016 j.nanoso.2017.08.013 https: pubpeer.com publications 7A123B2F1443D6AC355E4B633E05E2 2017 DOI: 10.1039 C6RA13142E https: pubpeer.com publications 333B326822135A21713764E73A2B86 2016 https: pubpeer.com publications F37615D2B93BBAAB41C4DCA099D5CD 2018 doi:10.1016 j.ijhydene.2018.07.122  ,