{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T18:48:01Z","timestamp":1775069281119,"version":"3.50.1"},"reference-count":48,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2024,4,13]],"date-time":"2024-04-13T00:00:00Z","timestamp":1712966400000},"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>Aerosols, as well as suspended particulate matter, impact atmospheric pollution, the climate, and human health, directly or indirectly. Particle size, chemical composition, and other aerosol characteristics are determinant factors for atmospheric pollution dynamics and more. In the last decade, low-cost devices have been widely used in instrumentation to measure aerosols. However, they present some issues, such as the problem of discriminating whether the aerosol is composed of liquid particles or solid. This issue could lead to errors in the estimation of mass concentration in monitoring environments where there is fog. In this study, we investigate the use of an optical particle counter (OPC) coupled to a quartz crystal microbalance with an integrated microheater (H-QCM) to enhance measurement performances. The H-QCM was used not only to measure the collected mass on its surface but also, by using the integrated microheater, it was able to heat the collected mass by performing heating cycles. In particular, we tested the developed system with aerosolized saline solutions of sodium chloride (NaCl), with three decreasing concentrations of salt and three electronic cigarette solutions (e-liquid), with different concentrations of propylene glycol and glycerin mixtures. The results showed that the OPC coherently counted the salt dilution effects, and the H-QCM output confirmed the presence of liquid and solid particles in the aerosols. In the case of e-liquid aerosols, the OPC counted the particles, and the HQCM output highlighted that in the aerosol, there were no solid particles but a liquid phase only. These findings contribute to the refinement of aerosol measurement methodologies by low-cost sensors, fostering a more comprehensive understanding.<\/jats:p>","DOI":"10.3390\/s24082500","type":"journal-article","created":{"date-parts":[[2024,4,15]],"date-time":"2024-04-15T08:08:12Z","timestamp":1713168492000},"page":"2500","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Improving Aerosol Characterization Using an Optical Particle Counter Coupled with a Quartz Crystal Microbalance with an Integrated Microheater"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4344-5547","authenticated-orcid":false,"given":"Emiliano","family":"Zampetti","sequence":"first","affiliation":[{"name":"Institute of Atmospheric Pollution Research\u2014National Research Council (IIA-CNR), Research Area of Rome 1, Strada Provinciale 35d, 9-00010 Montelibretti, Italy"}]},{"given":"Maria Aurora","family":"Mancuso","sequence":"additional","affiliation":[{"name":"Institute of Atmospheric Pollution Research\u2014National Research Council (IIA-CNR), Research Area of Rome 1, Strada Provinciale 35d, 9-00010 Montelibretti, Italy"}]},{"given":"Alessandro","family":"Capocecera","sequence":"additional","affiliation":[{"name":"Institute of Atmospheric Pollution Research\u2014National Research Council (IIA-CNR), Research Area of Rome 1, Strada Provinciale 35d, 9-00010 Montelibretti, Italy"}]},{"given":"Paolo","family":"Papa","sequence":"additional","affiliation":[{"name":"Institute of Atmospheric Pollution Research\u2014National Research Council (IIA-CNR), Research Area of Rome 1, Strada Provinciale 35d, 9-00010 Montelibretti, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6015-4832","authenticated-orcid":false,"given":"Antonella","family":"Macagnano","sequence":"additional","affiliation":[{"name":"Institute of Atmospheric Pollution Research\u2014National Research Council (IIA-CNR), Research Area of Rome 1, Strada Provinciale 35d, 9-00010 Montelibretti, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1032","DOI":"10.1016\/S0140-6736(10)60926-9","article-title":"Aerosol drug delivery: Developments in device design and clinical use","volume":"377","author":"Dolovich","year":"2011","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1080\/02786829308959650","article-title":"Aerosol processing of materials","volume":"19","author":"Gurav","year":"1993","journal-title":"Aerosol Sci. Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"7520","DOI":"10.1002\/anie.200501122","article-title":"Atmospheric aerosols: Composition, transformation, climate and health effects","volume":"44","year":"2005","journal-title":"Angew. Chem. Int. Ed. Engl."},{"key":"ref_4","first-page":"7","article-title":"Aerosols and their Relation to Global Climate and Climate Sensitivity","volume":"4","author":"Myhre","year":"2013","journal-title":"Nat. Educ. Knowl."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1080\/02786829808965573","article-title":"Methods of Aerosol Measurement before the 1960s","volume":"29","author":"Spurny","year":"1998","journal-title":"Aerosol Sci. Technol."},{"key":"ref_6","first-page":"D23209","article-title":"Measurements of atmospheric parameters during Indian Space Research Organization Geosphere Biosphere Programme Land Campaign II at a typical location in the Ganga basin: 1. Physical and optical properties","volume":"111","author":"Tripathi","year":"2006","journal-title":"J. Geophys. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"5923","DOI":"10.1038\/ncomms6923","article-title":"Size dependence of phase transitions in aerosol nanoparticles","volume":"6","author":"Cheng","year":"2015","journal-title":"Nat. Commun."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1959","DOI":"10.1016\/S1352-2310(99)00455-0","article-title":"A review of atmospheric aerosol measurements","volume":"34","author":"McMurry","year":"2000","journal-title":"Atmos. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1327","DOI":"10.3390\/atmos6091327","article-title":"An overview of particulate matter measurement instruments","volume":"6","author":"Amaral","year":"2015","journal-title":"Atmosphere"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"105584","DOI":"10.1016\/j.jaerosci.2020.105584","article-title":"Overview of measurements and current instrumentation for 1\u201310 nm aerosol particle number size distributions","volume":"148","author":"Kangasluoma","year":"2020","journal-title":"J. Aerosol Sci."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Vincent, J.H. (2007). Aerosol Sampling: Science, Standards, Instrumentation and Applications, John Wiley & Sons.","DOI":"10.1002\/9780470060230"},{"key":"ref_12","unstructured":"Wiedensohler, A., Birmili, W., Putaud, J.P., and Ogren, J. (2013). Aerosol Science: Technology and Applications, Wiley."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"462","DOI":"10.1080\/02786826.2016.1162901","article-title":"Inter-comparison of low-cost sensors for measuring the mass concentration of occupational aerosols","volume":"50","author":"Sousan","year":"2016","journal-title":"Aerosol Sci. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"105833","DOI":"10.1016\/j.jaerosci.2021.105833","article-title":"From low-cost sensors to high-quality data: A summary of challenges and best practices for effectively calibrating low-cost particulate matter mass sensors","volume":"158","author":"Giordano","year":"2021","journal-title":"J. Aerosol Sci."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Alfano, B., Barretta, L., Del Giudice, A., De Vito, S., Di Francia, G., Esposito, E., and Polichetti, T. (2020). A review of low-cost particulate matter sensors from the developers\u2019 perspectives. Sensors, 20.","DOI":"10.3390\/s20236819"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3022","DOI":"10.1021\/acsearthspacechem.1c00174","article-title":"Integrating fixed monitoring systems with low-cost sensors to create high-resolution air quality maps for the Northern China Plain Region","volume":"5","author":"Chao","year":"2021","journal-title":"ACS Earth Space Chem."},{"key":"ref_17","first-page":"717","article-title":"Experimental studies of optical particle counters","volume":"8","author":"Berglund","year":"1974","journal-title":"Atmos. Environ. 1967"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Steinem, C., and Janshoff, A. (2007). Piezoelectric Sensors, Springer Science & Business Media.","DOI":"10.1007\/b100347"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"709","DOI":"10.5194\/amt-11-709-2018","article-title":"Evaluation of a low-cost optical particle counter (Alphasense OPC-N2) for ambient air monitoring, Atmos","volume":"11","author":"Crilley","year":"2018","journal-title":"Meas. Tech."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"971","DOI":"10.1080\/02786826.2016.1213790","article-title":"A novel quartz crystal cascade impactor for real-time aerosol mass distribution measurement","volume":"50","author":"Chen","year":"2016","journal-title":"Aerosol Sci. Technol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"571405","DOI":"10.1155\/2011\/571405","article-title":"Recent Advances in Quartz Crystal Microbalance-Based Sensors","volume":"2011","author":"Vashist","year":"2011","journal-title":"J. Sens."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Afzal, A., Mujahid, A., Schirhagl, R., Bajwa, S.Z., Latif, U., and Feroz, S. (2017). Gravimetric Viral Diagnostics: QCM Based Biosensors for Early Detection of Viruses. Chemosensors, 5.","DOI":"10.3390\/chemosensors5010007"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2386","DOI":"10.1016\/j.asr.2014.08.030","article-title":"Thermo-mechanical design and testing of a microbalance for space applications","volume":"54","author":"Scaccabarozzi","year":"2014","journal-title":"Adv. Space Res."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Zampetti, E., Papa, P., Bearzotti, A., and Macagnano, A. (2021). Pocket Mercury-Vapour Detection System Employing a Preconcentrator Based on Au-TiO2 Nanomaterials. Sensors, 21.","DOI":"10.3390\/s21248255"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1039\/C1EM10558B","article-title":"Workplace aerosol mass concentration measurement using optical particle counters","volume":"14","author":"Simon","year":"2012","journal-title":"J. Environ. Monit."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1012","DOI":"10.1080\/02786820290092276","article-title":"A new method for retrieving particle refractive index and effective density from aerosol size distribution data","volume":"36","author":"Hand","year":"2002","journal-title":"Aerosol Sci. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"McMeeking, G.R., Kreidenweis, S.M., Carrico, C.M., Lee, T., Collett, J.L., and Malm, W.C. (2005). Observations of smoke-influenced aerosol during the Yosemite Aerosol Characterization Study: Size distributions and chemical composition. J. Geophys. Res. Atmos., 110.","DOI":"10.1029\/2004JD005389"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1181","DOI":"10.5194\/amt-13-1181-2020","article-title":"Effect of aerosol composition on the performance of low-cost optical particle counter correction factors","volume":"13","author":"Crilley","year":"2020","journal-title":"Atmos. Meas. Tech."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"113272","DOI":"10.1016\/j.sna.2021.113272","article-title":"Portable multilateral measurement system employing Optical Particle Counter and one-stage Quartz Crystal Microbalance to measure PM10","volume":"333","author":"Lee","year":"2022","journal-title":"Sens. Actuators A Phys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.sna.2017.08.004","article-title":"Exploitation of an integrated microheater on QCM sensor in particulate matter measurements","volume":"264","author":"Zampetti","year":"2017","journal-title":"Sens. Actuators A Phys."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"844","DOI":"10.1016\/j.jqsrt.2009.02.035","article-title":"Aerosol light absorption and its measurement: A review","volume":"110","author":"Chakrabarty","year":"2009","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.atmosenv.2013.10.011","article-title":"Deliquescence and efflorescence behavior of individual NaCl and KCl mixture aerosol particles","volume":"82","author":"Li","year":"2014","journal-title":"Atmos. Environ."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1270","DOI":"10.1080\/02786826.2020.1771270","article-title":"Effects of propylene glycol, vegetable glycerin, and nicotine on emissions and dynamics of electronic cigarette aerosols","volume":"54","author":"Li","year":"2020","journal-title":"Aerosol Sci. Technol."},{"key":"ref_34","first-page":"A4169","article-title":"Propylene Glycol and Glycerin in E-Cigarettes Elicit Respiratory Irritation Responses and Modulate Human Sensory Irritant Receptor Function","volume":"199","author":"Jordt","year":"2019","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"127560","DOI":"10.1016\/j.jhazmat.2021.127560","article-title":"Quartz crystal microbalance with thermally-controlled surface adhesion for an efficient fine dust collection and sensing","volume":"424","author":"Jang","year":"2022","journal-title":"J. Hazard. Mater."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1007\/BF01337937","article-title":"Verwendung von Schwingquarzen zur Wigung Diinner Schichten und zur Mikrowigung","volume":"155","author":"Sauerbrey","year":"1959","journal-title":"Z. Phys."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/S0003-2670(00)82721-X","article-title":"The oscillation frequency of a quartz resonator in contact with liquid","volume":"175","author":"Kanazawa","year":"1985","journal-title":"Anal. Chim. Acta"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Moon, S.-H., Chang, K.H., Park, H.M., Park, B.J., Yoo, S.K., and Nam, K.C. (2021). Effects of Driving Frequency and Voltage on the Performances of Vibrating Mesh Nebulizers. Appl. Sci., 11.","DOI":"10.3390\/app11031296"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"112878","DOI":"10.1016\/j.sna.2021.112878","article-title":"Calibration in cryogenic conditions of deposited thin-film thermometers on quartz crystal microbalances","volume":"330","author":"Scaccabarozzi","year":"2021","journal-title":"Sens. Actuators A Phys."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Magni, M., Scaccabarozzi, D., Palomba, E., Zampetti, E., and Saggin, B. (2022). Characterization of Thermal Gradient Effects on a Quartz Crystal Microbalance. Sensors, 22.","DOI":"10.3390\/s22197256"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1103\/RevModPhys.57.105","article-title":"Crystals for quartz resonators","volume":"57","author":"Brice","year":"1985","journal-title":"Rev. Mod. Phys."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"579","DOI":"10.5194\/acp-8-579-2008","article-title":"LACIS-measurements and parameterization of sea-salt particle hygroscopic growth and activation","volume":"8","author":"Niedermeier","year":"2008","journal-title":"Atmos. Chem. Phys."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"19245","DOI":"10.1029\/96JD03003","article-title":"Chemical and size effects of hygroscopic aerosols on light scattering coefficient","volume":"101","author":"Tang","year":"1996","journal-title":"J. Geophys. Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"859","DOI":"10.5194\/amt-9-859-2016","article-title":"Aerosol effective density measurement using scanning mobility particle sizer and quartz crystal microbalance with the estimation of involved uncertainty","volume":"9","author":"Sarangi","year":"2016","journal-title":"Atmos. Meas. Tech."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/S0925-4005(97)80249-3","article-title":"Study on behaviour of QCM sensor in loading variation","volume":"40","author":"Zhang","year":"1997","journal-title":"Sens. Actuators B Chem."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"31858","DOI":"10.1021\/acsomega.0c04698","article-title":"Water Adsorption vs Phase Transition of Aerosols Monitored by a Quartz Crystal Microbalance","volume":"5","author":"Chao","year":"2020","journal-title":"ACS Omega"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Zampetti, E., Mancuso, M.A., Dirri, F., Palomba, E., Papa, P., Capocecera, A., Bearzotti, A., Macagnano, A., and Scaccabarozzi, D. (2023). Effects of Oscillation Amplitude Variations on QCM Response to Microspheres of Different Sizes. Sensors, 23.","DOI":"10.3390\/s23125682"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"8426","DOI":"10.1002\/2015JD023303","article-title":"On the accuracy of stratospheric aerosol extinction derived from in situ size distribution measurements and surface area density derived from remote SAGE II and HALOE extinction measurements","volume":"120","author":"Kovilakam","year":"2015","journal-title":"J. Geophys. Res. Atmos."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/8\/2500\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:27:42Z","timestamp":1760106462000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/8\/2500"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4,13]]},"references-count":48,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2024,4]]}},"alternative-id":["s24082500"],"URL":"https:\/\/doi.org\/10.3390\/s24082500","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4,13]]}}}