TY  - JOUR
A1  - Molinnus, Denise
A1  - Beging, Stefan
A1  - Lowis, Carsten
A1  - Schöning, Michael Josef
T1  - Towards a multi-enzyme capacitive field-effect biosensor by comparative study of drop-coating and nano-spotting technique
JF  - Sensors
N2  - 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 µm and 102 µm, 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.
Y1  - 2020
SN  - 1424-8220
U6  - http://dx.doi.org/10.3390/s20174924
N1  - Special issue: Multisensor Systems and Signal Processing in Analytical Chemistry
VL  - 20
IS  - 17
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Lowis, Carsten
A1  - Ferguson, Simon
A1  - Paulßen, Elisabeth
A1  - Hoehr, Cornelia
T1  - Improved Sc-44 production in a siphon-style liquid target on a medical cyclotron
JF  - Applied Radiation and Isotopes
Y1  - 2021
U6  - http://dx.doi.org/10.1016/j.apradiso.2021.109675
SN  - 0969-8043
VL  - 172
IS  - Art. 109675
PB  - Elsevier
CY  - Amsterdam
ER  -