TY  - JOUR
A1  - Molinnus, Denise
A1  - Hardt, Gabriel
A1  - Siegert, Petra
A1  - Willenberg, Holger S.
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Detection of Adrenaline in Blood Plasma as Biomarker for Adrenal Venous Sampling
JF  - Electroanalysis
N2  - An amperometric bi-enzyme biosensor based on substrate recycling principle for the amplification of the sensor signal has been developed for the detection of adrenaline in blood. Adrenaline can be used as biomarker verifying successful adrenal venous sampling procedure. The adrenaline biosensor has been realized via modification of a galvanic oxygen sensor with a bi-enzyme membrane combining a genetically modified laccase and a pyrroloquinoline quinone-dependent glucose dehydrogenase. The measurement conditions such as pH value and temperature were optimized to enhance the sensor performance. A high sensitivity and a low detection limit of about 0.5–1 nM adrenaline have been achieved in phosphate buffer at pH 7.4, relevant for measurements in blood samples. The sensitivity of the biosensor to other catecholamines such as noradrenaline, dopamine and dobutamine has been studied. Finally, the sensor has been successfully applied for the detection of adrenaline in human blood plasma.
Y1  - 2018
U6  - https://doi.org/10.1002/elan.201800026
SN  - 1521-4109
VL  - 30
IS  - 5
SP  - 937
EP  - 942
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
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  - https://doi.org/10.1016/j.bios.2017.12.045
SN  - 0956-5663
VL  - 104
SP  - 87
EP  - 94
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Figueroa-Miranda, Gabriela
A1  - Feng, Lingyan
A1  - Shiu, Simon Chi-Chin
A1  - Dirkzwager, Roderick Marshall
A1  - Cheung, Yee-Wai
A1  - Tanner, Julian Alexander
A1  - Schöning, Michael Josef
A1  - Offenhäusser, Andreas
A1  - Mayer, Dirk
T1  - Aptamer-based electrochemical biosensor for highly sensitive and selective malaria detection with adjustable dynamic response range and reusability
JF  - Sensor and Actuators B: Chemical
N2  - Malaria infection remains a significant risk for much of the population of tropical and subtropical areas, particularly in developing countries. Therefore, it is of high importance to develop sensitive, accurate and inexpensive malaria diagnosis tests. Here, we present a novel aptamer-based electrochemical biosensor (aptasensor) for malaria detection by impedance spectroscopy, through the specific recognition between a highly discriminatory DNA aptamer and its target Plasmodium falciparum lactate dehydrogenase (PfLDH). Interestingly, due to the isoelectric point (pI) of PfLDH, the aptasensor response showed an adjustable detection range based on the different protein net-charge at variable pH environments. The specific aptamer recognition allows sensitive protein detection with an expanded detection range and a low detection limit, as well as a high specificity for PfLDH compared to analogous proteins. The specific feasibility of the aptasensor is further demonstrated by detection of the target PfLDH in human serum. Furthermore, the aptasensor can be easily regenerated and thus applied for multiple usages. The robustness, sensitivity, and reusability of the presented aptasensor make it a promising candidate for point-of-care diagnostic systems.
Y1  - 2018
U6  - https://doi.org/10.1016/j.snb.2017.07.117
SN  - 0925-4005
VL  - 255
IS  - P1
SP  - 235
EP  - 243
PB  - Elsevier
CY  - Amsterdam
ER  -