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This work proposes a miniaturized optical detection system, based on optical transmittance, for pH level quantification of the EGM\u2122-2 Endothelial Cell Growth Medium-2 BulletKit\u2122 culture medium. Firstly, using a commercial spectrophotometric setup, a set of wavelengths (500, 560, and 600 nm) was selected, as these wavelengths assure distinctive slope variations for the different pH levels. Then, a current-to-frequency converter, based on a low-power Schmitt trigger model with a voltage enhancer, was proposed as the readout electronics and simulated in Cadence Tools using UMC L180 MM\/RF technology. A resolution of 0.002 nA was achieved in the linear range of 30 pA to 3800 nA. A miniaturized system composed of a CMOS n-well\/p-substrate photodiode and a polydimethilsiloxane (PDMS) microchannel for the culture media substrate was experimentally tested. For a pH range from 6.6 to 6.2, the results clearly demonstrate a magnitude shift of the slope signal, which becomes negative in basic media and positive in acidic media. Additionally, in the 500\u2013560 nm spectral range, the amplitude of the slopes increases for both basic and acidic culture media. In the 560\u2013600 nm range, the slope decreases progressively as the pH of the medium lowers. This miniaturized system was able to quantify the pH of the culture medium, showing potential to be integrated into an organ-on-a-chip device.<\/jats:p>","DOI":"10.3390\/photonics11121130","type":"journal-article","created":{"date-parts":[[2024,12,2]],"date-time":"2024-12-02T03:50:57Z","timestamp":1733111457000},"page":"1130","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Complementary Metal Oxide Semiconductor-Based Optical Detection System for Fluidic Cellular Medium pH Quantification"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-0476-0461","authenticated-orcid":false,"given":"Andr\u00e9 A.","family":"Santos","sequence":"first","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), School of Engineering, Campus de Azur\u00e9m, University of Minho, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4336-7166","authenticated-orcid":false,"given":"Gabriel M.","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), School of Engineering, Campus de Azur\u00e9m, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2290-808X","authenticated-orcid":false,"given":"Paulo J.","family":"Sousa","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), School of Engineering, Campus de Azur\u00e9m, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"LABBELS\u2014Associate Laboratory, 4800-122 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2945-9267","authenticated-orcid":false,"given":"Patr\u00edcia C.","family":"Sousa","sequence":"additional","affiliation":[{"name":"International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8962-0710","authenticated-orcid":false,"given":"Susana O.","family":"Catarino","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), School of Engineering, Campus de Azur\u00e9m, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"LABBELS\u2014Associate Laboratory, 4800-122 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2460-0556","authenticated-orcid":false,"given":"Gra\u00e7a","family":"Minas","sequence":"additional","affiliation":[{"name":"Microelectromechanical Systems Research Unit (CMEMS-UMinho), School of Engineering, Campus de Azur\u00e9m, University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"LABBELS\u2014Associate Laboratory, 4800-122 Braga, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Danku, A.E., Dulf, E.H., Braicu, C., Jurj, A., and Berindan-Neagoe, I. (2022). Organ-On-A-Chip: A Survey of Technical Results and Problems. Front. Bioeng. Biotechnol., 10.","DOI":"10.3389\/fbioe.2022.840674"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2220","DOI":"10.1021\/acsbiomaterials.2c01454","article-title":"Organ-on-a-Chip for Drug Screening: A Bright Future for Sustainability? A Critical Review","volume":"9","author":"Feitor","year":"2023","journal-title":"ACS Biomater. Sci. Eng."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"533","DOI":"10.1016\/S1872-2040(16)60920-9","article-title":"Organs-on-chips and Its Applications","volume":"44","author":"Sun","year":"2016","journal-title":"Chin. J. Anal. Chem."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Clarke, G.A., Hartse, B.X., Niaraki Asli, A.E., Taghavimehr, M., Hashemi, N., Abbasi Shirsavar, M., Montazami, R., Alimoradi, N., Nasirian, V., and Ouedraogo, L.J. (2021). Advancement of Sensor Integrated Organ-on-Chip Devices. 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Organ-on-a-Chip Platforms for Drug Screening and Delivery in Tumor Cells: A Systematic Review. Cancers, 14.","DOI":"10.3390\/cancers14040935"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Tawade, P., and Mastrangeli, M. (2024). Integrated Electrochemical and Optical Biosensing in Organs-on-Chip. ChemBioChem, 25.","DOI":"10.1002\/cbic.202300560"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1","DOI":"10.21037\/mps.2018.01.01","article-title":"Organs-on-chip monitoring: Sensors and other strategies","volume":"1","author":"Kilic","year":"2018","journal-title":"Microphysiol. Syst."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"10072","DOI":"10.1007\/s12274-023-5651-9","article-title":"Sensors-integrated organ-on-a-chip for biomedical applications","volume":"16","author":"Chen","year":"2023","journal-title":"Nano Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/j.snb.2019.03.098","article-title":"A low-cost lab-on-a-chip device for marine pH quantification by colorimetry","volume":"290","author":"Pinto","year":"2019","journal-title":"Sens. Actuators B Chem."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Saetchnikov, A.V., Tcherniavskaia, E.A., Saetchnikov, V.A., and Ostendorf, A. (2024). Two-photon polymerization of optical microresonators for precise pH sensing. arXiv.","DOI":"10.37188\/lam.2024.054"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1109\/TBCAS.2021.3084540","article-title":"An Optical and Temperature Assisted CMOS ISFET Sensor Array for Robust E. coli Detection","volume":"15","author":"Duan","year":"2021","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_15","first-page":"E2293","article-title":"Multisensor-integrated organs-on-chips platform for automated and continual in situ monitoring of organoid behaviors","volume":"114","author":"Zhang","year":"2017","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1016\/j.snb.2007.06.027","article-title":"Measurement of pH and dissolved oxygen within cell culture media using a hydrogel microarray sensor","volume":"128","author":"Lee","year":"2008","journal-title":"Sens. Actuators B Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"117569","DOI":"10.1016\/j.trac.2024.117569","article-title":"Organ-on-a-chip platforms integrated with biosensors for precise monitoring of the cells and cellular microenvironment","volume":"172","author":"Yang","year":"2024","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Ferreira, G.M., Silva, V., Minas, G., and Catarino, S.O. (2022). Simulation Study of Vertical p\u2013n Junction Photodiodes\u2019 Optical Performance According to CMOS Technology. Appl. Sci., 12.","DOI":"10.3390\/app12052580"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Chandrasekharan, H.K., Wlodarczyk, K.L., MacPherson, W.N., and Maroto-Valer, M.M. (2023). In-situ multicore fibre-based pH mapping through obstacles in integrated microfluidic devices. arXiv.","DOI":"10.21203\/rs.3.rs-3443974\/v1"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3611","DOI":"10.1109\/JSEN.2015.2510579","article-title":"Real-Time Optical pH Sensor With CMOS Contact Imaging and Microfluidics","volume":"16","author":"Cao","year":"2016","journal-title":"IEEE Sens. J."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Morgan, A., Babu, D., Reiz, B., Whittal, R., Suh, L.Y.K., and Siraki, A.G. (2019). Caution for the routine use of phenol red\u2014It is more than just a pH indicator. Chem. Biol. Interact., 310.","DOI":"10.1016\/j.cbi.2019.108739"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"640","DOI":"10.1111\/cote.12626","article-title":"Spectrophotometry and colorimetry profiling of pure phenol red and cell culture medium on pH variation","volume":"138","author":"Raffay","year":"2022","journal-title":"Color. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1002\/bmb.21457","article-title":"A simple colorimetric experiment using mammalian cell culture to study metabolism","volume":"49","author":"Sharma","year":"2021","journal-title":"Biochem. Mol. Biol. Educ."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Gounella, R., Ferreira, G.M., Amorim, M.L.M., Soares, J.N., and Carmo, J.P. (2024). A Review of Optical Sensors in CMOS. Electronics, 13.","DOI":"10.3390\/electronics13040691"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Koklu, G., Etienne-Cummings, R., Leblebici, Y., De Micheli, G., and Carrara, S. (2013, January 19\u201323). Characterization of standard CMOS compatible photodiodes and pixels for Lab-on-Chip devices. Proceedings of the 2013 IEEE International Symposium on Circuits and Systems (ISCAS), Beijing, China.","DOI":"10.1109\/ISCAS.2013.6572036"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2318","DOI":"10.1109\/TBME.2023.3242691","article-title":"CMOS spectrophotometric microsystem for malaria detection","volume":"70","author":"Ferreira","year":"2023","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3438","DOI":"10.1109\/JSEN.2017.2691046","article-title":"CMOS Integrated Photodetectors and Light-to-Frequency Converters for Spectrophotometric Measurements","volume":"17","author":"Correia","year":"2017","journal-title":"IEEE Sens. J."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Jha, S.K., Verma, P., and Taleja, M. (2019, January 18\u201319). Design of Low Power CMOS Based Schmitt Trigger in 180 nm Technology. Proceedings of the 2019 4th International Conference on Internet of Things: Smart Innovation and Usages (IoT-SIU), Ghaziabad, India.","DOI":"10.1109\/IoT-SIU.2019.8777506"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"841","DOI":"10.1016\/j.microrel.2006.10.006","article-title":"Negative bias temperature instability: What do we understand?","volume":"47","author":"Schroder","year":"2007","journal-title":"Microelectron. Reliab."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.microrel.2004.03.019","article-title":"A comprehensive model of PMOS NBTI degradation","volume":"45","author":"Alam","year":"2005","journal-title":"Microelectron. Reliab."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Baker, R.J. (2010). CMOS: Circuit Design, Layout, and Simulation, Wiley. [3rd ed.].","DOI":"10.1002\/9780470891179"},{"key":"ref_32","unstructured":"Bucher, M., Lallement, C., Enz, C., Th\u00e9odoloz, F., and Krummenacher, F. (1997). The EPFL-EKV MOSFET Model Equations for Simulation, Eletronics Laboratory, Swiss Federal Institute of Technology. Technical Report."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1109\/JEDS.2020.3015265","article-title":"Characterization and Modeling of 0.18\u03bcm Bulk CMOS Technology at Sub-Kelvin Temperature","volume":"8","author":"Lu","year":"2020","journal-title":"IEEE J. Electron Devices Soc."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Miranda, I., Souza, A., Sousa, P., Ribeiro, J., Castanheira, E.M.S., Lima, R., and Minas, G. (2021). Properties and Applications of PDMS for Biomedical Engineering: A Review. J. Funct. Biomater., 13.","DOI":"10.3390\/jfb13010002"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Costa, M.S., Baptista, V., Ferreira, G.M., Lima, D., Minas, G., Veiga, M.I., and Catarino, S.O. (2021). Multilayer Thin-Film Optical Filters for Reflectance-Based Malaria Diagnostics. Micromachines, 12.","DOI":"10.3390\/mi12080890"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1393","DOI":"10.1002\/btpr.66","article-title":"Development and application of an excitation ratiometric optical pH sensor for bioprocess monitoring","volume":"24","author":"Badugu","year":"2008","journal-title":"Biotechnol. Prog."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1016\/S0165-9936(00)00034-0","article-title":"Recent development and applications of optical and fiber-optic pH sensors","volume":"19","author":"Lin","year":"2000","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1016\/0160-4120(84)90138-7","article-title":"A critical review of measurement practices for the determination of pH and acidity of atmospheric precipitation","volume":"10","author":"Marinenko","year":"1984","journal-title":"Environ. Int."}],"container-title":["Photonics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2304-6732\/11\/12\/1130\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:42:56Z","timestamp":1760114576000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2304-6732\/11\/12\/1130"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11,29]]},"references-count":38,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2024,12]]}},"alternative-id":["photonics11121130"],"URL":"https:\/\/doi.org\/10.3390\/photonics11121130","relation":{},"ISSN":["2304-6732"],"issn-type":[{"value":"2304-6732","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11,29]]}}}