TY  - JOUR
A1  - Molinnus, Denise
A1  - Hardt, G.
A1  - Käver, L.
A1  - Willenberg, H.S.
A1  - Kröger, J.-C.
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Chip-based biosensor for the detection of low adrenaline concentrations to support adrenal venous sampling
JF  - Sensor and Actuators B: Chemical
N2  - A chip-based amperometric biosensor referring on using the bioelectrocatalytical amplification principle for the detection of low adrenaline concentrations is presented. The adrenaline biosensor has been prepared by modification of a platinum thin-film electrode with an enzyme membrane containing the pyrroloquinoline quinone-dependent glucose dehydrogenase and glutaraldehyde. Measuring conditions such as temperature, pH value, and glucose concentration have been optimized to achieve a high sensitivity and a low detection limit of about 1 nM adrenaline measured in phosphate buffer at neutral pH value. The response of the biosensor to different catecholamines has also been proven. Long-term stability of the adrenaline biosensor has been studied over 10 days. In addition, the biosensor has been successfully applied for adrenaline detection in human blood plasma for future biomedical applications. Furthermore, preliminary experiments have been carried to detect the adrenaline-concentration difference measured in peripheral blood and adrenal venous blood, representing the adrenal vein sampling procedure of a physician.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.snb.2018.05.136
SN  - 0925-4005
VL  - 272
SP  - 21
EP  - 27
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Bandodkar, Amay J.
A1  - Molinnus, Denise
A1  - Mirza, Omar
A1  - Guinovart, Tomas
A1  - Windmiller, Joshua R.
A1  - Valdes-Ramirez, Gabriela
A1  - Andrade, Francisco J.
A1  - Schöning, Michael Josef
A1  - Wang, Joseph
T1  - Epidermal tattoo potentiometric sodium sensors with wireless signal transduction for continuous non-invasive sweat monitoring
JF  - Biosensors and bioelectronics
N2  - This article describes the fabrication, characterization and application of an epidermal temporary-transfer tattoo-based potentiometric sensor, coupled with a miniaturized wearable wireless transceiver, for real-time monitoring of sodium in the human perspiration. Sodium excreted during perspiration is an excellent marker for electrolyte imbalance and provides valuable information regarding an individual's physical and mental wellbeing. The realization of the new skin-worn non-invasive tattoo-like sensing device has been realized by amalgamating several state-of-the-art thick film, laser printing, solid-state potentiometry, fluidics and wireless technologies. The resulting tattoo-based potentiometric sodium sensor displays a rapid near-Nernstian response with negligible carryover effects, and good resiliency against various mechanical deformations experienced by the human epidermis. On-body testing of the tattoo sensor coupled to a wireless transceiver during exercise activity demonstrated its ability to continuously monitor sweat sodium dynamics. The real-time sweat sodium concentration was transmitted wirelessly via a body-worn transceiver from the sodium tattoo sensor to a notebook while the subjects perspired on a stationary cycle. The favorable analytical performance along with the wearable nature of the wireless transceiver makes the new epidermal potentiometric sensing system attractive for continuous monitoring the sodium dynamics in human perspiration during diverse activities relevant to the healthcare, fitness, military, healthcare and skin-care domains.
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.bios.2013.11.039
SN  - 1873-4235 (E-Journal); 0956-5663 (Print)
VL  - 54
SP  - 603
EP  - 609
PB  - Elsevier
CY  - Amsterdam
ER  -