TY  - JOUR
A1  - Oberländer, Jan
A1  - Mayer, Marlena
A1  - Greeff, Anton
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Spore-based biosensor to monitor the microbicidal efficacy of gaseous hydrogen peroxide sterilization processes
JF  - Biosensors and Bioelectronics
N2  - In this work, a spore-based biosensor is evaluated to monitor the microbicidal efficacy of sterilization processes applying gaseous hydrogen peroxide (H2O2). The sensor is based on interdigitated electrode structures (IDEs) that have been fabricated by means of thin-film technologies. Impedimetric measurements are applied to study the effect of sterilization process on spores of Bacillus atrophaeus. This resilient microorganism is commonly used in industry to proof the sterilization efficiency. The sensor measurements are accompanied by conventional microbiological challenge tests, as well as morphological characterizations with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The sensor measurements are correlated with the microbiological test routines. In both methods, namely the sensor-based and microbiological one, a tailing effect has been observed. The results are evaluated and discussed in a three-dimensional calibration plot demonstrating the sensor's suitability to enable a rapid process decision in terms of a successfully performed sterilization.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.bios.2017.12.045
SN  - 0956-5663
VL  - 104
SP  - 87
EP  - 94
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Oberländer, Jan
A1  - Arreola, Julio
A1  - Hansen, Christina
A1  - Greeff, Anton
A1  - Mayer, Marlena
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Impedimetric Biosensor to Enable Fast Evaluation of Gaseous Sterilization Processes
T2  - MDPI Proceedings
Y1  - 2017
U6  - http://dx.doi.org/10.3390/proceedings1040435
N1  - Eurosensors 2017 Conference, Paris, France, 3–6 September 2017
VL  - 1
IS  - 4
ER  - 
TY  - JOUR
A1  - Arreola, Julio
A1  - Mätzkow, Malte
A1  - Durán, Marlena Palomar
A1  - Greeff, Anton
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Optimization of the immobilization of bacterial spores on glass substrates with organosilanes
JF  - Physica status solidi (A) : Applications and materials science
N2  - Spores can be immobilized on biosensors to function as sensitive recognition elements. However, the immobilization can affect the sensitivity and reproducibility of the sensor signal. In this work, three different immobilization strategies with organosilanes were optimized and characterized to immobilize Bacillus atrophaeus spores on glass substrates. Five different silanization parameters were investigated: nature of the solvent, concentration of the silane, silanization time, curing process, and silanization temperature. The resulting silane layers were resistant to a buffer solution (e.g., Ringer solution) with a polysorbate (e.g., Tween®80) and sonication.
KW  - silanization
KW  - organosilanes
KW  - immobilization
KW  - endospores
KW  - biosensors
KW  - Bacillus atrophaeus
Y1  - 2016
U6  - http://dx.doi.org/10.1002/pssa.201532914
SN  - 1862-6319
VL  - 213
IS  - 6
SP  - 1463
EP  - 1470
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Oberländer, Jan
A1  - Bromm, Alexander
A1  - Wendeler, Luisa
A1  - Iken, Heiko
A1  - Palomar Duran, Marlena
A1  - Greeff, Anton
A1  - Kirchner, Patrick
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Towards a biosensor to monitor the sterilisation efficiency of aseptic filling machines
JF  - Physica status solidi (a)
N2  - Sterilisation processes are compulsory in medicine, pharmacy, and food industries to prevent infections of consumers and microbiological contaminations of products. Monitoring the sterilisation by conventional microbiological methods is time- and lab-consuming. To overcome this problem, in this work a novel biosensor has been proposed. The sensor enables a fast method to evaluate sterilisation processes. By means of thin-film technology the sensor's transducer structures in form of IDEs (interdigitated electrodes) have been fabricated on a silicon substrate. Physical characterisation of the developed sensor was done by AFM, SEM, and profilometry. Impedance analyses were conducted for the electrical characterisation. As microbiological layer spores of B. atrophaeus have been immobilised on the sensing structure; spores of this type are a well-known sterilisation test organism. Impedance measurements at a fixed frequency over time were performed to monitor the immobilisation process. A sterilisation process according to aseptic filling machines was applied to demonstrate the sensor functionality. After both, immobilisation and sterilisation, a change in impedance could successfully be detected.
Y1  - 2015
U6  - http://dx.doi.org/10.1002/pssa.201431900
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1299
EP  - 1305
PB  - Wiley
CY  - Weinheim
ER  -