{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T05:19:13Z","timestamp":1773119953459,"version":"3.50.1"},"reference-count":29,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2023,11,6]],"date-time":"2023-11-06T00:00:00Z","timestamp":1699228800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000780","name":"European Union\u2019s Horizon 2020 research and innovation program","doi-asserted-by":"publisher","award":["101016956"],"award-info":[{"award-number":["101016956"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000780","name":"European Union\u2019s Horizon 2020 research and innovation program","doi-asserted-by":"publisher","award":["PE0000023-NQSTI"],"award-info":[{"award-number":["PE0000023-NQSTI"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003407","name":"PolySenSe joint research laboratory","doi-asserted-by":"publisher","award":["101016956"],"award-info":[{"award-number":["101016956"]}],"id":[{"id":"10.13039\/501100003407","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003407","name":"PolySenSe joint research laboratory","doi-asserted-by":"publisher","award":["PE0000023-NQSTI"],"award-info":[{"award-number":["PE0000023-NQSTI"]}],"id":[{"id":"10.13039\/501100003407","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this work, we report on the implementation of a multi-quantum cascade laser (QCL) module as an innovative light source for quartz-enhanced photoacoustic spectroscopy (QEPAS) sensing. The source is composed of three different QCLs coupled with a dichroitic beam combiner module that provides an overlapping collimated beam output for all three QCLs. The 3\u03bb-QCL QEPAS sensor was tested for detection of NO2, SO2, and NH3 in sequence in a laboratory environment. Sensitivities of 19.99 mV\/ppm, 19.39 mV\/ppm, and 73.99 mV\/ppm were reached for NO2, SO2, and NH3 gas detection, respectively, with ultimate detection limits of 9 ppb, 9.3 ppb, and 2.4 ppb for these three gases, respectively, at an integration time of 100 ms. The detection limits were well below the values of typical natural abundance of NO2, SO2, and NH3 in air.<\/jats:p>","DOI":"10.3390\/s23219005","type":"journal-article","created":{"date-parts":[[2023,11,6]],"date-time":"2023-11-06T13:24:53Z","timestamp":1699277093000},"page":"9005","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Quartz-Enhanced Photoacoustic Sensor Based on a Multi-Laser Source for In-Sequence Detection of NO2, SO2, and NH3"],"prefix":"10.3390","volume":"23","author":[{"given":"Pietro","family":"Patimisco","sequence":"first","affiliation":[{"name":"PolySense Lab-Dipartimento Interateneo di Fisica, Politecnico and University of Bari, Via Amendola 173, I-70100 Bari, Italy"},{"name":"Polysense Innovations Srl 2, Via Amendola 173, I-70100 Bari, Italy"}]},{"given":"Nicoletta","family":"Ardito","sequence":"additional","affiliation":[{"name":"PolySense Lab-Dipartimento Interateneo di Fisica, Politecnico and University of Bari, Via Amendola 173, I-70100 Bari, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-1584-9386","authenticated-orcid":false,"given":"Edoardo","family":"De Toma","sequence":"additional","affiliation":[{"name":"Walter Schottky Institute, Technical University of Munich, Am Coulombwall 4, D-85748 Garching, Germany"}]},{"given":"Dominik","family":"Burghart","sequence":"additional","affiliation":[{"name":"Walter Schottky Institute, Technical University of Munich, Am Coulombwall 4, D-85748 Garching, Germany"}]},{"given":"Vladislav","family":"Tigaev","sequence":"additional","affiliation":[{"name":"Walter Schottky Institute, Technical University of Munich, Am Coulombwall 4, D-85748 Garching, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3172-9462","authenticated-orcid":false,"given":"Mikhail A.","family":"Belkin","sequence":"additional","affiliation":[{"name":"Walter Schottky Institute, Technical University of Munich, Am Coulombwall 4, D-85748 Garching, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4867-8166","authenticated-orcid":false,"given":"Vincenzo","family":"Spagnolo","sequence":"additional","affiliation":[{"name":"PolySense Lab-Dipartimento Interateneo di Fisica, Politecnico and University of Bari, Via Amendola 173, I-70100 Bari, Italy"},{"name":"Polysense Innovations Srl 2, Via Amendola 173, I-70100 Bari, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Tiwary, A., and Williams, I. (2019). Air Pollution: Measurement, Modelling and Mitigation, CRC Press. [4th ed.].","DOI":"10.1201\/9780429469985"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Saxena, P., and Naik, V. (2019). Air Pollution: Sources, Impacts and Controls, CAB International.","DOI":"10.1079\/9781786393890.0000"},{"key":"ref_3","unstructured":"Brusseau, M.L., Pepper, I.L., and Gerba, C.P. (2019). Environmental and Pollution Science, Academic Press."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Saxena, P., and Sonwani, S. (2019). Criteria Air Pollutants and Their Impact on Environmental Health, Springer.","DOI":"10.1007\/978-981-13-9992-3"},{"key":"ref_5","unstructured":"NRC (National Research Council), and Committee on Acute Exposure Guideline Levels (2008). Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 6, National Academies Press."},{"key":"ref_6","unstructured":"Barsan, M.E. (2007). NIOSH Pocket Guide to Chemical Hazards, U.S. Department of Health & Human Services."},{"key":"ref_7","unstructured":"World Health Organization (2021). WHO Global Air Quality Guidelines: Particulate Matter (PM2.5 and PM10), Ozone, Nitrogen Dioxide, Sulfur Dioxide and Carbon Monoxide: Executive Summary, World Health Organization."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1016\/S0921-8009(97)00181-X","article-title":"The determinants of atmospheric SO2 concentrations: Reconsidering the environmental Kuznets curve","volume":"25","author":"Kaufmann","year":"1998","journal-title":"Ecol. Econ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"106434","DOI":"10.1016\/j.envint.2021.106434","article-title":"Short-term exposure to sulphur dioxide (SO) and all-cause and respiratory mortality: A systematic review and meta-analysis","volume":"150","author":"Orellano","year":"2021","journal-title":"Environ. Int."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1007\/s00779-019-01206-3","article-title":"Personal pollution monitoring: Mobile real-time air quality in daily life","volume":"23","author":"Bales","year":"2019","journal-title":"Pers. Ubiquitous Comput."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/j.jenvman.2015.12.012","article-title":"Mapping real-time air pollution health risk for environmental management: Combining mobile and stationary air pollution monitoring with neural network models","volume":"168","author":"Adams","year":"2016","journal-title":"J. Environ. Manag."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Li, J., Yu, Z., Du, Z., Ji, Y., and Liu, C. (2020). Standoff chemical detection using laser absorption spectroscopy: A review. Remote Sens., 12.","DOI":"10.3390\/rs12172771"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"853966","DOI":"10.3389\/fphy.2022.853966","article-title":"Improvement of the Detection Sensitivity for Tunable Diode Laser Absorption Spectroscopy: A Review","volume":"10","author":"Lin","year":"2022","journal-title":"Front. Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"81","DOI":"10.5194\/amt-7-81-2014","article-title":"Open-path, quantum cascade-laser-based sensor for high-resolution atmospheric ammonia measurements","volume":"7","author":"Miller","year":"2014","journal-title":"Atmos. Meas. Tech."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1007\/s00340-017-6742-7","article-title":"Dual quantum cascade laser-based sensor for simultaneous NO and NO2 detection using a wavelength modulation-division multiplexing technique","volume":"123","author":"Yu","year":"2017","journal-title":"Appl. Phys. B"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1007\/s00340-022-07776-0","article-title":"Simultaneous measurements of SO2 and SO3 in the heterogeneous conversions of SO2 using QCL absorption spectroscopy","volume":"128","author":"Li","year":"2022","journal-title":"Appl. Phys. B"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1357","DOI":"10.1364\/AO.477575","article-title":"Real-time ultrasensitive detection of ammonia gas using a compact CRDS spectrometer","volume":"62","author":"Oh","year":"2023","journal-title":"Appl. Opt."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1926","DOI":"10.1021\/es103739r","article-title":"Detection of sulfur dioxide by cavity ring-down spectroscopy","volume":"45","author":"Medina","year":"2011","journal-title":"Environ. Sci. Technol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3223","DOI":"10.5194\/amt-12-3223-2019","article-title":"Simultaneous measurement of NO and NO2 by a dual-channel cavity ring-down spectroscopy technique","volume":"12","author":"Li","year":"2019","journal-title":"Atmos. Meas. Tech."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1902","DOI":"10.1364\/OL.27.001902","article-title":"Quartz-enhanced photoacoustic spectroscopy","volume":"27","author":"Kosterev","year":"2002","journal-title":"Opt. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Dello Russo, S., Giglio, M., Sampaolo, A., Patimisco, P., Menduni, G., Wu, H., Dong, L., Passaro, V.M.N., and Spagnolo, V. (2019). Acoustic coupling between resonator tubes in quartz-enhanced photoacoustic spectrophones employing a large prong spacing tuning fork. Sensors, 19.","DOI":"10.3390\/s19194109"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"338894","DOI":"10.1016\/j.aca.2021.338894","article-title":"Quartz-enhanced photoacoustic spectroscopy for multi-gas detection: A review","volume":"1202","author":"Sampaolo","year":"2022","journal-title":"Anal. Chim. Acta"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"132953","DOI":"10.1016\/j.snb.2022.132953","article-title":"Measurement of methane, nitrous oxide and ammonia in atmosphere with a compact quartz-enhanced photoacoustic sensor","volume":"375","author":"Menduni","year":"2023","journal-title":"Sens. Actuators B Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"118118","DOI":"10.1016\/j.fuel.2020.118118","article-title":"Quartz-enhanced photoacoustic spectroscopy for hydrocarbon trace gas detection and petroleum exploration","volume":"277","author":"Sampaolo","year":"2020","journal-title":"Fuel"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"100159","DOI":"10.1016\/j.pacs.2019.100159","article-title":"Broadband detection of methane and nitrous oxide using a distributed-feedback quantum cascade laser array and quartz-enhanced photoacoustic sensing","volume":"17","author":"Giglio","year":"2020","journal-title":"Photoacoustics"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"25943","DOI":"10.1364\/OE.24.025943","article-title":"Purely wavelength- and amplitude-modulated quartz-enhanced photoacoustic spectroscopy","volume":"24","author":"Patimisco","year":"2016","journal-title":"Opt. Express"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"107949","DOI":"10.1016\/j.jqsrt.2021.107949","article-title":"The HITRAN2020 molecular spectroscopic database","volume":"277","author":"Gordon","year":"2022","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1013","DOI":"10.1002\/kin.550151006","article-title":"Formation of nitrous acid and nitric oxide in the heterogeneous dark reaction of nitrogen dioxide and water vapor in a smog chamber","volume":"15","author":"Sakamaki","year":"1983","journal-title":"Int. J. Chem. Kinet."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1109\/TUFFC.2015.2495013","article-title":"Allan Deviation Plot as a Tool for Quartz-Enhanced Photoacoustic Sensors Noise Analysis","volume":"63","author":"Giglio","year":"2016","journal-title":"IEEE Trans. Ultrason. Ferroelectr. Freq. Control"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/21\/9005\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:18:21Z","timestamp":1760131101000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/21\/9005"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,6]]},"references-count":29,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2023,11]]}},"alternative-id":["s23219005"],"URL":"https:\/\/doi.org\/10.3390\/s23219005","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,11,6]]}}}