{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,18]],"date-time":"2026-01-18T09:01:15Z","timestamp":1768726875526,"version":"3.49.0"},"reference-count":50,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2017,11,2]],"date-time":"2017-11-02T00:00:00Z","timestamp":1509580800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this work, uniformly-dispersed platinum nanoparticles (PtNPs) were synthesized by a simple chemical reduction method, in which citric acid and sodium borohydride acted as a stabilizer and reducer, respectively. An ultrasensitive colorimetric sensor for the facile and rapid detection of Ag+ ions was constructed based on the peroxidase mimetic activities of the obtained PtNPs, which can catalyze the oxidation of 3,3\u2019,5,5\u2019-tetramethylbenzidine (TMB) by H2O2 to produce colored products. The introduced Ag+ would be reduced to Ag0 by the capped citric acid, and the deposition of Ag0 on the PtNPs surface, can effectively inhibit the peroxidase-mimetic activity of PtNPs. Through measuring the maximum absorption signal of oxidized TMB at 652 nm, ultra-low detection limits (7.8 pM) of Ag+ can be reached. In addition to such high sensitivity, the colorimetric assay also displays excellent selectivity for other ions of interest and shows great potential for the detection of Ag+ in real water samples.<\/jats:p>","DOI":"10.3390\/s17112521","type":"journal-article","created":{"date-parts":[[2017,11,3]],"date-time":"2017-11-03T04:43:13Z","timestamp":1509684193000},"page":"2521","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":30,"title":["A Simple Assay for Ultrasensitive Colorimetric Detection of Ag+ at Picomolar Levels Using Platinum Nanoparticles"],"prefix":"10.3390","volume":"17","author":[{"given":"Yi-Wei","family":"Wang","sequence":"first","affiliation":[{"name":"Key Laboratory of Predictive Microbiology and Chemical Residual Analysis, College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China"}]},{"given":"Meili","family":"Wang","sequence":"additional","affiliation":[{"name":"The Key Lab of Analysis and Detection Technology for Food Safety of the MOE, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350108, China"}]},{"given":"Lixing","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Predictive Microbiology and Chemical Residual Analysis, College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China"}]},{"given":"Hui","family":"Xu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Predictive Microbiology and Chemical Residual Analysis, College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China"}]},{"given":"Shurong","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China"}]},{"given":"Huang-Hao","family":"Yang","sequence":"additional","affiliation":[{"name":"The Key Lab of Analysis and Detection Technology for Food Safety of the MOE, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350108, China"}]},{"given":"Lan","family":"Zhang","sequence":"additional","affiliation":[{"name":"The Key Lab of Analysis and Detection Technology for Food Safety of the MOE, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350108, China"}]},{"given":"Hongbo","family":"Song","sequence":"additional","affiliation":[{"name":"Key Laboratory of Predictive Microbiology and Chemical Residual Analysis, College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China"}]}],"member":"1968","published-online":{"date-parts":[[2017,11,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/j.phytochem.2003.10.022","article-title":"Horseradish peroxidase: A modern view of a classic enzyme","volume":"65","author":"Veitch","year":"2004","journal-title":"Phytochemistry"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1125","DOI":"10.1007\/s12274-017-1426-5","article-title":"Surface modification of nanozymes","volume":"10","author":"Liu","year":"2017","journal-title":"Nano Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1038\/nnano.2007.260","article-title":"Intrinsic peroxidase-like activity of ferromagnetic nanoparticles","volume":"2","author":"Gao","year":"2007","journal-title":"Nat. Nanotechnol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"6676","DOI":"10.1039\/C5AN01103E","article-title":"Glutathione-stabilized palladium nanozyme for colorimetric assay of silver(I) ions","volume":"140","author":"Fu","year":"2015","journal-title":"Analyst"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4464","DOI":"10.1039\/C5AY00365B","article-title":"Synthesis and sensing application of glutathione-capped platinum nanoparticles","volume":"7","author":"Li","year":"2015","journal-title":"Anal. Methods"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2445","DOI":"10.1007\/s00604-017-2223-2","article-title":"In-situ amplified voltammetric immunoassay for ochratoxin A by coupling a platinum nanocatalyst based enhancement to a redox cycling process promoted by an enzyme mimic","volume":"184","author":"Zhang","year":"2017","journal-title":"Microchim. Acta"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Tong, Y., Jiao, X., Yang, H., Wen, Y., Su, L., and Zhang, X. (2016). Reverse-bumpy-ball-type-nanoreactor-loaded nylon membranes as peroxidase-mimic membrane reactors for a colorimetric assay for H2O2. Sensors, 16.","DOI":"10.3390\/s16040465"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"4225","DOI":"10.1007\/s00216-017-0372-0","article-title":"Cobalt oxyhydroxide nanoflakes with intrinsic peroxidase catalytic activity and their application to serum glucose detection","volume":"409","author":"Wang","year":"2017","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1016\/j.aca.2017.05.019","article-title":"Graphitic carbon nitride supported platinum nanocomposites for rapid and sensitive colorimetric detection of mercury ions","volume":"980","author":"Wang","year":"2017","journal-title":"Anal. Chim. Acta"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1233","DOI":"10.1007\/s00604-017-2147-x","article-title":"A sensitive colorimetric assay for cholesterol based on the peroxidase-like activity of MoS2 nanosheets","volume":"184","author":"Lin","year":"2017","journal-title":"Microchim. Acta"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"570","DOI":"10.1016\/j.nano.2009.12.002","article-title":"Silver nanoparticles as a safe preservative for use in cosmetics","volume":"6","author":"Kokura","year":"2010","journal-title":"Nanomed. Nanotechnol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1799","DOI":"10.2355\/isijinternational.43.1799","article-title":"Silver containing stainless steel as a new outlook to abate bacterial adhesion and microbiologically influenced corrosion","volume":"43","author":"Sreekumari","year":"2003","journal-title":"ISIJ Int."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1007\/s10534-013-9645-z","article-title":"Antimicrobial silver: Uses, toxicity and potential for resistance","volume":"26","author":"Mijnendonckx","year":"2013","journal-title":"Biometals"},{"key":"ref_14","unstructured":"EPA CASRN (1989). EPA Drinking Water Criteria Document for Silver. Environ. Prot. Agency, 444, 7440\u20137444."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1002\/etc.5620180112","article-title":"Bioaccumulation and toxicity of silver compounds: A review","volume":"18","author":"Ratte","year":"1999","journal-title":"Environ. Toxicol. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1277","DOI":"10.1016\/S0584-8547(02)00068-X","article-title":"Analytical procedures for the determination of selected trace elements in peat and plant samples by inductively coupled plasma mass spectrometry","volume":"57","author":"Krachler","year":"2002","journal-title":"Spectrochim. Acta B"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1618","DOI":"10.1039\/c0ja00018c","article-title":"Silver chemical vapor generation for atomic absorption spectrometry: Minimization of transport losses, interferences and application to water analysis","volume":"25","author":"Musil","year":"2010","journal-title":"J. Anal. At. Spectrom."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1166\/sl.2004.043","article-title":"Detection of aqueous metals using a microglow discharge atomic emission sensor","volume":"2","author":"Zorn","year":"2004","journal-title":"Sens. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"12142","DOI":"10.1021\/ja002535y","article-title":"Self-assembly of CdSe-ZnS quantum dot bioconjugates using an engineered recombinant protein","volume":"122","author":"Mattoussai","year":"2000","journal-title":"J. Am. Chem. Soc."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4014","DOI":"10.1021\/acs.analchem.6b00327","article-title":"A silver DNAzyme","volume":"88","author":"Saran","year":"2016","journal-title":"Anal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1016\/j.bios.2014.11.032","article-title":"BSA-stabilized Pt nanozyme for peroxidase mimetics and its application on colorimetric detection of mercury(II) ions","volume":"66","author":"Li","year":"2015","journal-title":"Biosens. Bioelectron."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"7531","DOI":"10.1039\/C6AY01789D","article-title":"Highly sensitive colorimetric detection of copper ions based on regulating the peroxidase-like activity of Au@ Pt nanohybrids","volume":"8","author":"Pan","year":"2016","journal-title":"Anal. Methods"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"692","DOI":"10.1016\/j.snb.2016.04.039","article-title":"BSA-stabilized Au clusters as peroxidase mimetic for colorimetric detection of Ag+","volume":"232","author":"Chang","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3399","DOI":"10.1007\/s00604-017-2361-6","article-title":"Ultrathin two-dimensional MnO2 nanosheet as a stable coreactant of 3,3\u2019,5,5\u2019-tetramethylbenzidine chromogenic substrate for visual and colorimetric detection of iron (II) ion","volume":"184","author":"Song","year":"2017","journal-title":"Microchim. Acta"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1021\/jz201599u","article-title":"From single Pt atoms to Pt nanocrystals: Photoreduction of Pt2+ inside of a PAMAM dendrimer","volume":"3","author":"Borodko","year":"2012","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"846","DOI":"10.1016\/j.elecom.2009.02.009","article-title":"Preparation and electrochemical performance for methanol oxidation of pt\/graphene nanocomposites","volume":"11","author":"Li","year":"2009","journal-title":"Electrochem. Commun."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"5715","DOI":"10.1021\/jp068381b","article-title":"Different sized platinum nanoparticles supported on carbon: An XPS study on these methanol oxidation catalysts","volume":"111","author":"Fatih","year":"2007","journal-title":"J. Phys. Chem. C"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/S1010-6030(00)00264-1","article-title":"Quantum yields of active oxidative species formed on TiO2 photocatalyst","volume":"134","author":"Ishibashi","year":"2000","journal-title":"J. Photochem. Photobiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2540","DOI":"10.1039\/c2cc17013b","article-title":"Intrinsic peroxidase-like activity and catalase-like activity of Co3O4 nanoparticles","volume":"48","author":"Mu","year":"2012","journal-title":"Chem. Commun."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"6695","DOI":"10.1039\/c1cc11943e","article-title":"Carbon nanodots as peroxidase mimetics and their applications to glucose detection","volume":"47","author":"Shi","year":"2011","journal-title":"Chem. Commun."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4552","DOI":"10.1039\/c2an35700c","article-title":"BSA-templated MnO2 nanoparticles as both peroxidase and oxidase mimics","volume":"137","author":"Liu","year":"2012","journal-title":"Analyst"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1139","DOI":"10.1016\/j.biomaterials.2010.09.040","article-title":"Au@ Pt nanostructures as oxidase and peroxidase mimetics for use in immunoassays","volume":"32","author":"He","year":"2011","journal-title":"Biomaterials"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.aca.2015.01.016","article-title":"Cytidine-stabilized gold nanocluster as a fluorescence turn-on and turn-off probe for dual functional detection of Ag+ and Hg2+","volume":"870","author":"Zhang","year":"2015","journal-title":"Anal. Chim. Acta"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2251","DOI":"10.1039\/c2nr12056a","article-title":"Microwave-assisted synthesis of BSA-protected small gold nanoclusters and their fluorescence-enhanced sensing of silver(I) ions","volume":"4","author":"Yue","year":"2012","journal-title":"Nanoscale"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"825","DOI":"10.1016\/j.matchemphys.2010.09.049","article-title":"Visible-light-responsive Ag\u2013Si codoped anatase TiO2 photocatalyst with enhanced thermal stability","volume":"125","author":"Chen","year":"2011","journal-title":"Mater. Chem. Phys."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"15415","DOI":"10.1039\/C4CC06659F","article-title":"Graphitic carbon nitride solid nanofilms for selective and recyclable sensing of Cu2+ and Ag+ in water and serum","volume":"50","author":"Huang","year":"2014","journal-title":"Chem. Commun."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"8337","DOI":"10.1021\/ja8005258","article-title":"Mechanistic study of photomediated triangular silver nanoprism growth","volume":"130","author":"Xue","year":"2008","journal-title":"J. Am. Chem. Soc."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.colsurfa.2012.06.012","article-title":"Influence of oxygen on the process of formation of silver nanoparticles during citrate\/borohydride synthesis of silver sols","volume":"410","author":"Wojtysiak","year":"2012","journal-title":"Colloid. Surf. A"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"2253","DOI":"10.1021\/nn204313a","article-title":"Citrate-coated gold nanoparticles as smart scavengers for mercury(II) removal from polluted waters","volume":"6","author":"Arbiol","year":"2012","journal-title":"ACS Nano"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"496","DOI":"10.1016\/j.bios.2016.10.075","article-title":"Colorimetric response of peptide modified gold nanoparticles: An original assay for ultrasensitive silver detection","volume":"92","author":"Li","year":"2017","journal-title":"Biosens. Bioelectron."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"4363","DOI":"10.1039\/C7AY01317E","article-title":"Colorimetric assay for the simultaneous detection of Hg2+ and Ag+ based on inhibiting the peroxidase-like activity of core-shell Au@ Pt nanoparticles","volume":"9","author":"Peng","year":"2017","journal-title":"Anal. Methods"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"641","DOI":"10.1016\/j.snb.2017.05.020","article-title":"Colorimetric detection of Ag+ based on C-Ag+-C binding as a bridge between gold nanoparticles","volume":"250","author":"Xi","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1016\/j.snb.2016.11.043","article-title":"Colorimetric sensing of silver ion based on anti aggregation of gold nanoparticles","volume":"242","author":"Safavi","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"566","DOI":"10.1016\/j.bios.2016.08.093","article-title":"MnO2 nanosheet-assisted ligand-DNA interaction-based fluorescence polarization biosensor for the detection of Ag+ ions","volume":"87","author":"Qi","year":"2017","journal-title":"Biosens. Bioelectron."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"2625","DOI":"10.1007\/s00216-015-8467-y","article-title":"Turn-on sensing for Ag+ based on AIE-active fluorescent probe and cytosine-rich DNA","volume":"407","author":"Ma","year":"2015","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"8059","DOI":"10.1039\/C6AY02539K","article-title":"Signal-on electrochemical sensor for the detection of two analytes based on the conformational changes of DNA probes","volume":"8","author":"Wang","year":"2016","journal-title":"Anal. Methods"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"3940","DOI":"10.1021\/acsami.6b14247","article-title":"DNA modified Fe3O4@ Au magnetic nanoparticles as selective probes for simultaneous detection of heavy metal ions","volume":"9","author":"Miao","year":"2017","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1568","DOI":"10.1021\/am200130e","article-title":"Blue-to-red colorimetric sensing strategy for Hg2+ and Ag+ via redox-regulated surface chemistry of gold nanoparticles","volume":"3","author":"Lou","year":"2011","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1039\/C4EE01463D","article-title":"Extraordinary role of Hg in enhancing the thermoelectric performance of p-type SnTe","volume":"8","author":"Tan","year":"2015","journal-title":"Energy Environ. Sci."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2028","DOI":"10.1002\/smll.201102590","article-title":"Well-defined nanoclusters as fluorescent nanosensors: A case study on Au25(SG)18","volume":"8","author":"Wu","year":"2012","journal-title":"Small"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/11\/2521\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:49:11Z","timestamp":1760208551000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/11\/2521"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,11,2]]},"references-count":50,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2017,11]]}},"alternative-id":["s17112521"],"URL":"https:\/\/doi.org\/10.3390\/s17112521","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,11,2]]}}}