{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,17]],"date-time":"2025-10-17T13:47:18Z","timestamp":1760708838907,"version":"build-2065373602"},"reference-count":35,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2015,5,20]],"date-time":"2015-05-20T00:00:00Z","timestamp":1432080000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000923","name":"Australian Research Council","doi-asserted-by":"publisher","award":["CE140100003"],"award-info":[{"award-number":["CE140100003"]}],"id":[{"id":"10.13039\/501100000923","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Cell phones and smart phones can be reconfigured as biomedical sensor devices but this requires specialized add-ons. In this paper we present a simple cell phone-based portable bioassay platform, which can be used with fluorescent assays in solution. The system consists of a tablet, a polarizer, a smart phone (camera) and a box that provides dark readout conditions. The assay in a well plate is placed on the tablet screen acting as an excitation source. A polarizer on top of the well plate separates excitation light from assay fluorescence emission enabling assay readout with a smartphone camera. The assay result is obtained by analysing the intensity of image pixels in an appropriate colour channel. With this device we carried out two assays, for collagenase and trypsin using fluorescein as the detected fluorophore. The results of collagenase assay with the lowest measured concentration of 3.75 \u00b5g\/mL and 0.938 \u00b5g in total in the sample were comparable to those obtained by a microplate reader. The lowest measured amount of trypsin was 930 pg, which is comparable to the low detection limit of 400 pg for this assay obtained in a microplate reader. The device is sensitive enough to be used in point-of-care medical diagnostics of clinically relevant conditions, including arthritis, cystic fibrosis and acute pancreatitis.<\/jats:p>","DOI":"10.3390\/s150511653","type":"journal-article","created":{"date-parts":[[2015,5,20]],"date-time":"2015-05-20T11:05:46Z","timestamp":1432119946000},"page":"11653-11664","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["Medically Relevant Assays with a Simple Smartphone and Tablet Based Fluorescence Detection System"],"prefix":"10.3390","volume":"15","author":[{"given":"Piotr","family":"Wargocki","sequence":"first","affiliation":[{"name":"ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, North Ryde 2109, NSW, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Deng","sequence":"additional","affiliation":[{"name":"ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, North Ryde 2109, NSW, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ayad","family":"Anwer","sequence":"additional","affiliation":[{"name":"ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, North Ryde 2109, NSW, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ewa","family":"Goldys","sequence":"additional","affiliation":[{"name":"ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, North Ryde 2109, NSW, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,5,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1006\/abio.1993.1504","article-title":"A fluorescence-based protein assay for use with a microplate reader","volume":"214","author":"Lorenzen","year":"1993","journal-title":"Anal. Biochem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1016\/S0891-5849(99)00107-0","article-title":"Quantifying cellular oxidative stress by dichlorofluorescein assay using microplate reader1","volume":"27","author":"Wang","year":"1999","journal-title":"Free Radic. Biol. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"413","DOI":"10.3109\/00365528209182078","article-title":"Serum phospholipase A2, immunoreactive trypsin, and trypsin inhibitors during human acute pancreatitis","volume":"17","author":"Mero","year":"1982","journal-title":"Scand. J. Gastroenterol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e32672","DOI":"10.1371\/journal.pone.0032672","article-title":"Protease activity increases in plasma, peritoneal fluid, and vital organs after hemorrhagic shock in rats","volume":"7","author":"Altshuler","year":"2012","journal-title":"PLoS ONE"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2011","DOI":"10.1093\/clinchem\/29.12.2011","article-title":"Cystic fibrosis\u2013\u2013Its biochemical detection","volume":"29","author":"Heeley","year":"1983","journal-title":"Clin. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1002\/art.1780350106","article-title":"Detection of stromelysin and collagenase in synovial fluid from patients with rheumatoid arthritis and posttraumatic knee injury","volume":"35","author":"Walakovits","year":"1992","journal-title":"Arthritis Rheum."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"51","DOI":"10.31053\/1853.0605.v57.n1.37207","article-title":"Collagenase production increases in rheumatoid arthritis and osteoarthritis synoviocytes incubated","volume":"57","author":"Montrull","year":"2000","journal-title":"Rev. Fac. Cien. Med. Univ. Nac. Cordoba"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2415","DOI":"10.1373\/clinchem.2005.051532","article-title":"Enzyme Immunoassay (EIA)\/Enzyme-Linked Immunosorbent Assay (ELISA)","volume":"51","author":"Lequin","year":"2005","journal-title":"Clin. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1136\/pgmj.57.666.219","article-title":"Serum trypsin levels in acute pancreatic and non-pancreatic abdominal conditions","volume":"57","author":"Artigas","year":"1981","journal-title":"Postgrad. Med. J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"838","DOI":"10.1093\/clinchem\/19.8.838","article-title":"Design, construction, and two applications for an automated flow\u2014cell polarization fluorometer with digital read out: Enzyme-inhibitor (antitrypsin) assay and antigen\u2014antibody (insulin\u2014insulin antiserum) assay","volume":"19","author":"Spencer","year":"1973","journal-title":"Clin. Chem."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/0003-2697(80)90270-5","article-title":"Fluorescence polarization assay of plasmin, plasminogen, and plasminogen activator","volume":"104","author":"Kinoshita","year":"1980","journal-title":"Anal. Biochem."},{"key":"ref_12","first-page":"1039","article-title":"Use of fluorescein-labeled fibrin for the determination of fibrinolytic activity","volume":"59","author":"Pappenhagen","year":"1962","journal-title":"J. Lab. Clin. Med."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/0005-2795(80)90216-0","article-title":"Indications for an oligomeric structure and for conformational changes in sarcoplasmic reticulum Ca2+-ATPase labelled selectively with fluorescein","volume":"626","author":"Pick","year":"1980","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1074\/jbc.M108195200","article-title":"Orthogonality of calcium concentration and ability of 4,5-diaminofluorescein to detect no","volume":"277","author":"Suzuki","year":"2002","journal-title":"J. Biol. Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1161\/01.ATV.0000168573.10844.ae","article-title":"Binding and internalization of C-reactive protein by Fcgamma receptors on human aortic endothelial cells mediates biological effects","volume":"25","author":"Devaraj","year":"2005","journal-title":"Arterioscler. Thromb. Vasc. Biol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"8805","DOI":"10.1021\/ac502080t","article-title":"Smartphone fluorescence spectroscopy","volume":"86","author":"Yu","year":"2014","journal-title":"Anal. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4267","DOI":"10.1039\/c0lc00357c","article-title":"A simple device for multiplex ELISA made from melt-extruded plastic microcapillary film","volume":"11","author":"Edwards","year":"2011","journal-title":"Lab Chip"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"9147","DOI":"10.1021\/nn4037706","article-title":"Fluorescent imaging of single nanoparticles and viruses on a smart phone","volume":"7","author":"Wei","year":"2013","journal-title":"ACS Nano"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1284","DOI":"10.1039\/C4LC01358A","article-title":"Rapid imaging, detection and quantification of Giardia lamblia cysts using mobile-phone based fluorescent microscopy and machine learning","volume":"15","author":"Koydemir","year":"2015","journal-title":"Lab Chip"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1039\/C0LC00358A","article-title":"Cost-effective and compact wide-field fluorescent imaging on a cell-phone","volume":"11","author":"Zhu","year":"2011","journal-title":"Lab Chip"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"6641","DOI":"10.1021\/ac201587a","article-title":"Optofluidic fluorescent imaging cytometry on a cell phone","volume":"83","author":"Zhu","year":"2011","journal-title":"Anal. Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1039\/C2LC40864C","article-title":"Optical imaging techniques for point-of-care diagnostics","volume":"13","author":"Zhu","year":"2013","journal-title":"Lab Chip"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2205","DOI":"10.1007\/s10439-014-1055-z","article-title":"Smartphones for cell and biomolecular detection","volume":"42","author":"Liu","year":"2014","journal-title":"Ann. Biomed. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"273re1","DOI":"10.1126\/scitranslmed.aaa0056","article-title":"A smartphone dongle for diagnosis of infectious diseases at the point of care","volume":"7","author":"Laksanasopin","year":"2015","journal-title":"Sci. Transl. Med."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3060","DOI":"10.1021\/nn5072792","article-title":"Integrated quantum dot barcode smartphone optical device for wireless multiplexed diagnosis of infected patients","volume":"9","author":"Ming","year":"2015","journal-title":"ACS Nano"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"4015","DOI":"10.1039\/c3lc50589h","article-title":"Smart-phone based computational microscopy using multi-frame contact imaging on a fiber-optic array","volume":"13","author":"Navruz","year":"2013","journal-title":"Lab Chip"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2678","DOI":"10.1039\/c2lc40235a","article-title":"Integrated rapid-diagnostic-test reader platform on a cellphone","volume":"12","author":"Mudanyali","year":"2012","journal-title":"Lab Chip"},{"key":"ref_28","unstructured":"Lim, J.S. (1989). Two-Dimensional Signal and Image Processing, Prentice Hall PTR. [1st ed.]."},{"key":"ref_29","unstructured":"Nexus 7 (2013)\u2013\u2013Mini Review. Available online: http:\/\/www.anandtech.com\/show\/7176\/nexus-7-2013-mini-review."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"472","DOI":"10.1016\/S0140-6736(79)90825-0","article-title":"Dried-blood spot screening for cytic fibrosis in the newborn","volume":"313","author":"Crossle","year":"1979","journal-title":"Lancet"},{"key":"ref_31","first-page":"18","article-title":"Screening for cystic fibrosis by dried blood spot trypsin assay","volume":"57","author":"Heeley","year":"1982","journal-title":"Arch. Dis Child."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"970","DOI":"10.1136\/ard.54.12.970","article-title":"Determination of interstitial collagenase (MMP-1) in patients with rheumatoid arthritis","volume":"54","author":"Maeda","year":"1995","journal-title":"Ann. Rheum. Dis."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"372","DOI":"10.1002\/art.1780360313","article-title":"The measurement of collagenase, tissue inhibitor of metalloproteinases (TIMP), and collagenase-TIMP complex in synovial fluids from patients with osteoarthritis and rheumatoid arthritis","volume":"36","author":"Clark","year":"1993","journal-title":"Arthritis Rheum."},{"key":"ref_34","unstructured":"Mini Tablet Display Technology Shoot-out. Available online: http:\/\/www.displaymate.com\/Tablet_ShootOut_4.htm."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/j.bios.2014.08.027","article-title":"A smartphone-based colorimetric reader for bioanalytical applications using the screen-based bottom illumination provided by gadgets","volume":"67","author":"Vashist","year":"2015","journal-title":"Biosens. Bioelectron."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/5\/11653\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:46:37Z","timestamp":1760215597000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/5\/11653"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,5,20]]},"references-count":35,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2015,5]]}},"alternative-id":["s150511653"],"URL":"https:\/\/doi.org\/10.3390\/s150511653","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2015,5,20]]}}}