{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T03:05:45Z","timestamp":1778814345326,"version":"3.51.4"},"reference-count":37,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2020,8,31]],"date-time":"2020-08-31T00:00:00Z","timestamp":1598832000000},"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>Multi-enzyme immobilization onto a capacitive field-effect biosensor by nano-spotting technique is presented. The nano-spotting technique allows to immobilize different enzymes simultaneously on the sensor surface with high spatial resolution without additional photolithographical patterning. The amount of applied enzymatic cocktail on the sensor surface can be tailored. Capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensors with Ta2O5 as pH-sensitive transducer layer have been chosen to immobilize the three different (pL droplets) enzymes penicillinase, urease, and glucose oxidase. Nano-spotting immobilization is compared to conventional drop-coating method by defining different geometrical layouts on the sensor surface (fully, half-, and quarter-spotted). The drop diameter is varying between 84 \u00b5m and 102 \u00b5m, depending on the number of applied drops (1 to 4) per spot. For multi-analyte detection, penicillinase and urease are simultaneously nano-spotted on the EIS sensor. Sensor characterization was performed by C\/V (capacitance\/voltage) and ConCap (constant capacitance) measurements. Average penicillin, glucose, and urea sensitivities for the spotted enzymes were 81.7 mV\/dec, 40.5 mV\/dec, and 68.9 mV\/dec, respectively.<\/jats:p>","DOI":"10.3390\/s20174924","type":"journal-article","created":{"date-parts":[[2020,8,31]],"date-time":"2020-08-31T08:11:19Z","timestamp":1598861479000},"page":"4924","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Towards a Multi-Enzyme Capacitive Field-Effect Biosensor by Comparative Study of Drop-Coating and Nano-Spotting Technique"],"prefix":"10.3390","volume":"20","author":[{"given":"Denise","family":"Molinnus","sequence":"first","affiliation":[{"name":"Institute of Nano- and Biotechnologies (INB), FH Aachen, Campus J\u00fclich, 52428 J\u00fclich, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stefan","family":"Beging","sequence":"additional","affiliation":[{"name":"Institute of Nano- and Biotechnologies (INB), FH Aachen, Campus J\u00fclich, 52428 J\u00fclich, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Carsten","family":"Lowis","sequence":"additional","affiliation":[{"name":"Institute of Nano- and Biotechnologies (INB), FH Aachen, Campus J\u00fclich, 52428 J\u00fclich, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4347-6685","authenticated-orcid":false,"given":"Michael J.","family":"Sch\u00f6ning","sequence":"additional","affiliation":[{"name":"Institute of Nano- and Biotechnologies (INB), FH Aachen, Campus J\u00fclich, 52428 J\u00fclich, Germany"},{"name":"Institute of Biological Information Processing (IBI-3), Research Center J\u00fclich, 52425 J\u00fclich, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1433","DOI":"10.1039\/b817836d","article-title":"A regenerable immunochip for the rapid determination of 13 different antibiotics in raw milk","volume":"134","author":"Kloth","year":"2009","journal-title":"Analyst"},{"key":"ref_2","first-page":"985","article-title":"Simultaneous multianalyte immunoassay measurement of five serum tumor markers in the detection of colorectal cancer","volume":"32","author":"Lumachi","year":"2012","journal-title":"Anticancer Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"15716","DOI":"10.1364\/OE.23.015716","article-title":"Multi-channel SPR biosensor based on PCF for multi-analyte sensing applications","volume":"23","author":"Otupiri","year":"2015","journal-title":"Opt. Express"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"9890","DOI":"10.1021\/ja505278w","article-title":"Highly selective fluorogenic multianalyte biosensors constructed via enzyme-catalyzed coupling and aggregation-induced emission","volume":"136","author":"Wang","year":"2014","journal-title":"J. Am. Chem. Soc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1109\/MP.2006.1649009","article-title":"Biosensors: A tutorial review","volume":"25","author":"Mohanty","year":"2006","journal-title":"IEEE Potentials"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"152","DOI":"10.2174\/1573411014666180319152853","article-title":"Recent advances in biosensors based nanostructure for pharmaceutical analysis","volume":"15","author":"Pourbasheer","year":"2019","journal-title":"Curr. Anal. Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1080\/14737159.2019.1554435","article-title":"Label-free plasmonic biosensors for point-of-care diagnostics: A review","volume":"19","author":"Soler","year":"2019","journal-title":"Expert Rev. Mol. Diagn."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1007\/s13197-011-0437-6","article-title":"Optical biosensors for food quality and safety assurance\u2015A review","volume":"49","author":"Narsaiah","year":"2012","journal-title":"J. Food Sci. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"937","DOI":"10.1002\/elan.201800026","article-title":"Detection of adrenaline in blood plasma as biomarker for adrenal venous sampling","volume":"30","author":"Molinnus","year":"2018","journal-title":"Electroanalysis"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1382","DOI":"10.1002\/pssa.201431913","article-title":"Concept for a biomolecular logic chip with an integrated sensor and actuator function","volume":"212","author":"Molinnus","year":"2015","journal-title":"Phys. Status Solidi A"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"183","DOI":"10.12944\/CRNFSJ.5.3.02","article-title":"The use of electrochemical biosensors in food analysis","volume":"5","author":"Bunney","year":"2017","journal-title":"Curr. Res. Nutr. Food Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.procbio.2018.09.016","article-title":"Trends on enzyme immobilization researches based on bibliometric analysis","volume":"76","author":"Kieckbusch","year":"2019","journal-title":"Process Biochem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/j.biotechadv.2011.09.003","article-title":"Immobilization strategies to develop enzymatic biosensors","volume":"30","author":"Sassolas","year":"2012","journal-title":"Biotechnol. Adv."},{"key":"ref_14","unstructured":"Singh, B.D. (2012). Biotechnology. Expanding Horizons, Kalyani Publishers. [4th ed.]."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1080\/13102818.2015.1008192","article-title":"An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes","volume":"29","author":"Mohamad","year":"2015","journal-title":"Biotechnol. Biotechnol. Equip."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4995","DOI":"10.1039\/c2sm00044j","article-title":"Writing with liquid using a nanodispenser: Spreading dynamics at the sub-micron scale","volume":"8","year":"2012","journal-title":"Soft Matter"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3148","DOI":"10.1039\/c1lc20326f","article-title":"Pyroelectric adaptive nanodispenser (PYRANA) microrobot for liquid delivery on a target","volume":"11","author":"Vespini","year":"2011","journal-title":"Lab Chip"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"13020","DOI":"10.1021\/jp075714b","article-title":"Evaporation of femtoliter sessile droplets monitored with nanomechanical mass sensors","volume":"111","author":"Arcamone","year":"2007","journal-title":"J. Phys. Chem. B"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1366","DOI":"10.1002\/smll.200800819","article-title":"Ultrasmall liquid droplets on solid surfaces: Production, imaging, and relevance for current wetting research","volume":"5","year":"2009","journal-title":"Small"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1896","DOI":"10.1021\/ac0012039","article-title":"On-demand droplet spotter for preparing pico- to femtoliter droplets on surfaces","volume":"73","author":"Yogi","year":"2001","journal-title":"Anal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2991","DOI":"10.1021\/ac035135c","article-title":"On-demand mixing droplet spotter for preparing picoliter droplets on surfaces","volume":"76","author":"Yogi","year":"2004","journal-title":"Anal. Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1353","DOI":"10.1002\/pssa.201431891","article-title":"Studying the spatially resolved immobilisation of enzymes on a capacitive field-effect structure by means of nano-spotting","volume":"212","author":"Beging","year":"2015","journal-title":"Phys. Status Solidi A"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/S0925-4005(03)00070-4","article-title":"Multi-parameter detection of (bio-)chemical and physical quantities using an identical transducer principle","volume":"91","author":"Poghossian","year":"2003","journal-title":"Sens. Actuators B Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"126","DOI":"10.3390\/s5030126","article-title":"\u201cPlaying around\u201d with field-effect sensors on the basis of EIS structures, LAPS and ISFETs","volume":"5","year":"2005","journal-title":"Sensors"},{"key":"ref_25","first-page":"423","article-title":"CIP (cleaning-in-place) suitable \u201cnon-glass\u201d pH sensor based on a Ta2O5-gate EIS structure","volume":"111\u2013112","author":"Brinkmann","year":"2005","journal-title":"Sens. Actuators B Chem."},{"key":"ref_26","first-page":"207","article-title":"Penicillin detection by means of silicon-based field-effect structures","volume":"13","author":"Poghossian","year":"2001","journal-title":"Sens. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/S0925-4005(03)00071-6","article-title":"A capacitive field-effect sensor for the direct determination of organophosphorus pesticides","volume":"91","author":"Arzdorf","year":"2003","journal-title":"Sens. Actuators B Chem."},{"key":"ref_28","unstructured":"Grimes, C.A., Dickey, E.C., and Pishko, M.V. (2006). Silicon-based chemical and biological field-effect sensors. Encyclopedia of Sensors, American Scientific Publishers. [9th ed.]."},{"key":"ref_29","unstructured":"(2020, August 24). sciFLEXARRAYERs. Available online: https:\/\/www.scienion.com\/products\/sciflexarrayers."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1016\/j.bios.2009.07.007","article-title":"Penicillin biosensor based on a capacitive field-effect structure functionalized with a dendrimer\/carbon nanotube multilayer","volume":"25","author":"Siqueira","year":"2009","journal-title":"Biosens. Bioelectron."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4562","DOI":"10.3390\/s110504562","article-title":"Optimization of urea-EnFET based on Ta2O5 layer with post annealing","volume":"11","author":"Lue","year":"2011","journal-title":"Sensors"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"474","DOI":"10.1016\/j.snb.2009.02.063","article-title":"A TiO2\/Er2O3 stacked electrolyte\/insulator\/semiconductor film pH-sensor for the detection of urea","volume":"138","author":"Pan","year":"2009","journal-title":"Sens. Actuators B Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"462","DOI":"10.1002\/pssa.200880483","article-title":"Carbon nanotubes in nanostructured films: Potential application as amperometric and potentiometric field-effect (bio-)chemical sensors","volume":"206","author":"Siqueira","year":"2009","journal-title":"Phys. Status Solidi (a)"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/S0925-4005(01)00629-3","article-title":"Glucose ENFET doped with MnO2 powder","volume":"76","author":"Yin","year":"2001","journal-title":"Sens. Actuators B Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1295","DOI":"10.1016\/j.bios.2003.11.019","article-title":"A novel glucose ENFET based on the special reactivity of MnO2 nanoparticles","volume":"19","author":"Luo","year":"2004","journal-title":"Biosens. Bioelectron."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1016\/j.snb.2004.04.072","article-title":"New concepts of miniaturised reference electrodes in silicon technology for potentiometric sensor systems","volume":"103","author":"Simonis","year":"2004","journal-title":"Sens. Actuators B Chem."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"925","DOI":"10.1002\/pssa.201100710","article-title":"Label-free electrical detection of DNA by means of field-effect nanoplate capacitors: Experiments and modeling","volume":"209","author":"Abouzar","year":"2012","journal-title":"Phys. Status Solidi A"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/17\/4924\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:05:07Z","timestamp":1760177107000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/17\/4924"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,8,31]]},"references-count":37,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2020,9]]}},"alternative-id":["s20174924"],"URL":"https:\/\/doi.org\/10.3390\/s20174924","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,8,31]]}}}