@article{WeldenSeverinsPoghossianetal.2022, author = {Welden, Melanie and Severins, Robin and Poghossian, Arshak and Wege, Christina and Bongaerts, Johannes and Siegert, Petra and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Detection of acetoin and diacetyl by a tobacco mosaic virus-assisted field-effect biosensor}, series = {Chemosensors}, volume = {10}, journal = {Chemosensors}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {2227-9040}, doi = {10.3390/chemosensors10060218}, pages = {Artikel 218}, year = {2022}, abstract = {Acetoin and diacetyl have a major impact on the flavor of alcoholic beverages such as wine or beer. Therefore, their measurement is important during the fermentation process. Until now, gas chromatographic techniques have typically been applied; however, these require expensive laboratory equipment and trained staff, and do not allow for online monitoring. In this work, a capacitive electrolyte-insulator-semiconductor sensor modified with tobacco mosaic virus (TMV) particles as enzyme nanocarriers for the detection of acetoin and diacetyl is presented. The enzyme acetoin reductase from Alkalihalobacillus clausii DSM 8716ᵀ is immobilized via biotin-streptavidin affinity, binding to the surface of the TMV particles. The TMV-assisted biosensor is electrochemically characterized by means of leakage-current, capacitance-voltage, and constant capacitance measurements. In this paper, the novel biosensor is studied regarding its sensitivity and long-term stability in buffer solution. Moreover, the TMV-assisted capacitive field-effect sensor is applied for the detection of diacetyl for the first time. The measurement of acetoin and diacetyl with the same sensor setup is demonstrated. Finally, the successive detection of acetoin and diacetyl in buffer and in diluted beer is studied by tuning the sensitivity of the biosensor using the pH value of the measurement solution.}, language = {en} } @article{WeldenPoghossianVahidpouretal.2022, author = {Welden, Melanie and Poghossian, Arshak and Vahidpour, Farnoosh and Wendlandt, Tim and Keusgen, Michael and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {Towards multi-analyte detection with field-effect capacitors modified with tobacco mosaic virus bioparticles as enzyme nanocarriers}, series = {Biosensors}, volume = {12}, journal = {Biosensors}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {2079-6374}, doi = {10.3390/bios12010043}, pages = {Artikel 43}, year = {2022}, abstract = {Utilizing an appropriate enzyme immobilization strategy is crucial for designing enzyme-based biosensors. Plant virus-like particles represent ideal nanoscaffolds for an extremely dense and precise immobilization of enzymes, due to their regular shape, high surface-to-volume ratio and high density of surface binding sites. In the present work, tobacco mosaic virus (TMV) particles were applied for the co-immobilization of penicillinase and urease onto the gate surface of a field-effect electrolyte-insulator-semiconductor capacitor (EISCAP) with a p-Si-SiO₂-Ta₂O₅ layer structure for the sequential detection of penicillin and urea. The TMV-assisted bi-enzyme EISCAP biosensor exhibited a high urea and penicillin sensitivity of 54 and 85 mV/dec, respectively, in the concentration range of 0.1-3 mM. For comparison, the characteristics of single-enzyme EISCAP biosensors modified with TMV particles immobilized with either penicillinase or urease were also investigated. The surface morphology of the TMV-modified Ta₂O₅-gate was analyzed by scanning electron microscopy. Additionally, the bi-enzyme EISCAP was applied to mimic an XOR (Exclusive OR) enzyme logic gate.}, language = {en} } @article{WeigandCollaniSaniga1994, author = {Weigand, Christoph and Collani, E. v. and Saniga, E.M.}, title = {Economic Adjustment Design for -Control Charts. E.v.Collani, E.M. Saniga, Ch. Weigand}, series = {IIE Transactions / Institute of Industrial Engineers. 26 (1994), H. 6}, journal = {IIE Transactions / Institute of Industrial Engineers. 26 (1994), H. 6}, isbn = {0569-5554}, year = {1994}, language = {en} } @article{Weigand1992, author = {Weigand, Christoph}, title = {Economic Machine Adjustment in the Case of Product Screening .E.v.Collani, Ch. Weigand}, series = {Statistical Papers. 33 (1992)}, journal = {Statistical Papers. 33 (1992)}, pages = {171 -- 184}, year = {1992}, language = {en} } @article{Weigand2009, author = {Weigand, Christoph}, title = {Defining Precisions for Reliable Measurement and Estimation Procedures}, series = {Economic Quality Control. 24 (2009), H. 1}, journal = {Economic Quality Control. 24 (2009), H. 1}, publisher = {De Gruyter}, address = {Berlin}, isbn = {0940-5151}, pages = {5 -- 33}, year = {2009}, language = {en} } @article{Weigand2003, author = {Weigand, Christoph}, title = {Economically Optimal Inspection Policy with Geometrical Adaption}, series = {Journal of Applied Statistics. 30 (2003), H. 5}, journal = {Journal of Applied Statistics. 30 (2003), H. 5}, isbn = {0266-4763}, pages = {555 -- 569}, year = {2003}, language = {en} } @article{Weigand2001, author = {Weigand, Christoph}, title = {Economically Optimal Inspection Policy with Arithmetical Adaption}, series = {Applied stochastic models and data analysis / [10th International Symposium on Applied Stochastic Models and Analysis, June 12-15 2001, Universit{\´e} Technologique de Compi{\`e}gne] ; editors G{\´e}rard Govaert, Jacques Janssen, Nikolaos Limnios.}, journal = {Applied stochastic models and data analysis / [10th International Symposium on Applied Stochastic Models and Analysis, June 12-15 2001, Universit{\´e} Technologique de Compi{\`e}gne] ; editors G{\´e}rard Govaert, Jacques Janssen, Nikolaos Limnios.}, publisher = {Universit{\´e} Technologique de Compi{\`e}gne}, address = {Compi{\`e}gne}, pages = {1010 -- 1015}, year = {2001}, language = {en} } @article{Weigand1994, author = {Weigand, Christoph}, title = {Optimal Production Schedule for a K Products Single Machine Problem}, series = {Economic Quality Control. 9 (1994)}, journal = {Economic Quality Control. 9 (1994)}, isbn = {0940-5151}, pages = {91 -- 101}, year = {1994}, language = {en} } @article{Weigand2012, author = {Weigand, Christoph}, title = {Statistical Tests Based on Reliability and Precision}, series = {Economic Quality Control : EQC ; international journal for quality and reliability}, volume = {27}, journal = {Economic Quality Control : EQC ; international journal for quality and reliability}, number = {1}, publisher = {De Gruyter}, address = {Berlin}, issn = {1869-6147}, doi = {10.1515/eqc-2012-0002}, pages = {43 -- 64}, year = {2012}, abstract = {The construction of a statistical test is investigated which is based only on "reliability" and "precision" as quality criteria. The reliability of a statistical test is quantifiedin a straightforward way by the probability that the decision of the test is correct. However, the quantification of the precision of a statistical test is not at all evident. Thereforethe paper presents and discusses several approaches. Moreover the distinction of "nullhypothesis" and "alternative hypothesis" is not necessary any longer.}, language = {en} } @article{Weigand1991, author = {Weigand, Christoph}, title = {A Solution to the Scheduling Problem Taking into Account Quality}, series = {Operations research '91 : extended abstracts of the 16th Symposium on Operations Research held at the University of Trier at September 9 - 11, 1991 / [GM{\"O}OR]. Peter Gritzmann ... (eds.)}, journal = {Operations research '91 : extended abstracts of the 16th Symposium on Operations Research held at the University of Trier at September 9 - 11, 1991 / [GM{\"O}OR]. Peter Gritzmann ... (eds.)}, publisher = {Physica-Verl.}, address = {Heidelberg}, isbn = {3790806080}, pages = {373 -- 375}, year = {1991}, language = {en} }