{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T14:11:41Z","timestamp":1785507101661,"version":"3.56.0"},"reference-count":35,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T00:00:00Z","timestamp":1785456000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004731","name":"Zhejiang Natural Science Foundation","doi-asserted-by":"publisher","award":["LGF22F010008"],"award-info":[{"award-number":["LGF22F010008"]}],"id":[{"id":"10.13039\/501100004731","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004731","name":"Zhejiang Natural Science Foundation","doi-asserted-by":"publisher","award":["LGG21F040001"],"award-info":[{"award-number":["LGG21F040001"]}],"id":[{"id":"10.13039\/501100004731","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100007834","name":"Ningbo Natural Science Foundation","doi-asserted-by":"publisher","award":["202003 N4362"],"award-info":[{"award-number":["202003 N4362"]}],"id":[{"id":"10.13039\/100007834","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100007834","name":"Ningbo Natural Science Foundation","doi-asserted-by":"publisher","award":["202003 N4332"],"award-info":[{"award-number":["202003 N4332"]}],"id":[{"id":"10.13039\/100007834","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Medical Scientific Research Foundation of Zhejiang Province","award":["2023KY279"],"award-info":[{"award-number":["2023KY279"]}]},{"name":"Medical Scientific Research Foundation of Zhejiang Province","award":["2025KY261"],"award-info":[{"award-number":["2025KY261"]}]},{"name":"Medical Scientific Research Foundation of Zhejiang Province","award":["2025KY268"],"award-info":[{"award-number":["2025KY268"]}]},{"name":"Zhu Xiu Shan Talent Project of Ningbo No. 2 Hospital","award":["2023HMJQ25"],"award-info":[{"award-number":["2023HMJQ25"]}]},{"award":["2023HMJQ25"],"award-info":[{"award-number":["2023HMJQ25"]}],"id":[{"id":"https:\/\/ror.org\/01apc5d07","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>High-performance ammonia (NH3) sensors play a critical role in environmental protection and noninvasive medical diagnosis. This work reports a new NH3 sensor based on Au-microsphere-decorated polyaniline (PANI) manufactured by a precise in situ inkjet printing method on a MEMS micro-hotplate. The in situ oxidative polymerization of aniline was performed directly on the MEMS platform using AuCl3 as a bifunctional oxidant and precursor, with a hierarchical morphology of microspheres (~750 nm) and nanorods (~250 nm). Reduced from Au3+ in the polymerization reaction, Au microparticles achieve substantial catalytic promotion by virtue of chemical sensitization and spillover effect. The optimized Au\u2013PANI MEMS sensor exhibits a superlative response of 201% toward 1 ppm NH3 at room temperature, with an ultra-low theoretical limit of detection (LOD) of 0.42 ppb. Furthermore, the device demonstrates rapid response\/recovery kinetics (76 s\/72 s), exceptional selectivity against common interfering gases (SO2, CO, H2, etc.), and robust long-term stability with high response retention over two months. This research provides a scalable, cost-effective strategy for the mass production of miniaturized, high-sensitivity gas sensors for industrial and healthcare applications.<\/jats:p>","DOI":"10.3390\/mi17080925","type":"journal-article","created":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T13:23:20Z","timestamp":1785504200000},"page":"925","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["One-Step In Situ Inkjet Printing Fabrication of Au-Decorated Polyaniline on MEMS Platforms for Sensitive Ammonia Sensing at ppb-Level"],"prefix":"10.3390","volume":"17","author":[{"given":"Jin","family":"Zhang","sequence":"first","affiliation":[{"name":"Ningbo No.2 Hospital, Ningbo 315099, China"},{"name":"Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dawu","family":"Lv","sequence":"additional","affiliation":[{"name":"Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China"},{"name":"Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6036-416X","authenticated-orcid":false,"given":"Ye","family":"Yang","sequence":"additional","affiliation":[{"name":"Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China"},{"name":"Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8129-8889","authenticated-orcid":false,"given":"Weijie","family":"Song","sequence":"additional","affiliation":[{"name":"Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China"},{"name":"Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruijin","family":"Yu","sequence":"additional","affiliation":[{"name":"College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3370-9801","authenticated-orcid":false,"given":"Wenfeng","family":"Shen","sequence":"additional","affiliation":[{"name":"Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China"},{"name":"Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China"},{"name":"Research and Manufacturing Base of Olfactory Sensors in China Sensing Valley, Bengbu 233040, China"},{"name":"CS-Microsensor (Ningbo) Technology Co., Ltd., Ningbo 311121, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"167264","DOI":"10.1016\/j.apsusc.2026.167264","article-title":"Interfacial amplification of NH3 sensing at low temperature using Au-decorated MoSe2\/Ti3C2Tx MXene heterostructures","volume":"742","author":"Yoon","year":"2026","journal-title":"Appl. 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