TY  - CHAP
A1  - Koch, Claudia
A1  - Poghossian, Arshak
A1  - Wege, Christina
A1  - Schöning, Michael Josef
ED  - Wege, Christina
T1  - TMV-Based Adapter Templates for Enhanced Enzyme Loading in Biosensor Applications
T2  - Virus-Derived Nanoparticles for Advanced Technologies
N2  - Nanotubular tobacco mosaic virus (TMV) particles and RNA-free lower-order coat protein (CP) aggregates have been employed as enzyme carriers in different diagnostic layouts and compared for their influence on biosensor performance. In the following, we describe a label-free electrochemical biosensor for improved glucose detection by use of TMV adapters and the enzyme glucose oxidase (GOD). A specific and efficient immobilization of streptavidin-conjugated GOD ([SA]-GOD) complexes on biotinylated TMV nanotubes or CP aggregates was achieved via bioaffinity binding. Glucose sensors with adsorptively immobilized [SA]-GOD, and with [SA]-GOD cross-linked with glutardialdehyde, respectively, were tested in parallel on the same sensor chip. Comparison of these sensors revealed that TMV adapters enhanced the amperometric glucose detection remarkably, conveying highest sensitivity, an extended linear detection range and fastest response times. These results underline a great potential of an integration of virus/biomolecule hybrids with electronic transducers for applications in biosensorics and biochips. Here, we describe the fabrication and use of amperometric sensor chips combining an array of circular Pt electrodes, their loading with GOD-modified TMV nanotubes (and other GOD immobilization methods), and the subsequent investigations of the sensor performance.
KW  - Tobacco mosaic virus (TMV)
KW  - Coat protein
KW  - Enzyme nanocarrier
KW  - Glucose biosensor
KW  - Glucose oxidase
Y1  - 2018
SN  - 978-1-4939-7808-3
U6  - http://dx.doi.org/10.1007/978-1-4939-7808-3
N1  - Methods in Molecular Biology, vol 1776
SP  - 553
EP  - 568
PB  - Humana Press
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Koch, Claudia
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Wege, Christian
T1  - Penicillin Detection by Tobacco Mosaic Virus-Assisted Colorimetric Biosensors
JF  - Nanotheranostics
N2  - The presentation of enzymes on viral scaffolds has beneficial effects such as an increased enzyme loading and a prolonged reusability in comparison to conventional immobilization platforms. Here, we used modified tobacco mosaic virus (TMV) nanorods as enzyme carriers in penicillin G detection for the first time. Penicillinase enzymes were conjugated with streptavidin and coupled to TMV rods by use of a bifunctional biotin-linker. Penicillinase-decorated TMV particles were characterized extensively in halochromic dye-based biosensing. Acidometric analyte detection was performed with bromcresol purple as pH indicator and spectrophotometry. The TMV-assisted sensors exhibited increased enzyme loading and strongly improved reusability, and higher analysis rates compared to layouts without viral adapters. They extended the half-life of the sensors from 4 - 6 days to 5 weeks and thus allowed an at least 8-fold longer use of the sensors. Using a commercial budget-priced penicillinase preparation, a detection limit of 100 µM penicillin was obtained. Initial experiments also indicate that the system may be transferred to label-free detection layouts.
Y1  - 2018
U6  - http://dx.doi.org/10.7150/ntno.22114
SN  - 2206-7418
VL  - 2
IS  - 2
SP  - 184
EP  - 196
PB  - Ivyspring
CY  - Sydney
ER  - 
TY  - JOUR
A1  - Bronder, Thomas
A1  - Jessing, Max P.
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Detection of PCR-Amplified Tuberculosis DNA Fragments with Polyelectrolyte-Modified Field-Effect Sensors
JF  - Analytical Chemistry
N2  - Field-effect-based electrolyte-insulator-semiconductor (EIS) sensors were modified with a bilayer of positively charged weak polyelectrolyte (poly(allylamine hydrochloride) (PAH)) and probe single-stranded DNA (ssDNA) and are used for the detection of complementary single-stranded target DNA (cDNA) in different test solutions. The sensing mechanism is based on the detection of the intrinsic molecular charge of target cDNA molecules after the hybridization event between cDNA and immobilized probe ssDNA. The test solutions contain synthetic cDNA oligonucleotides (with a sequence of tuberculosis mycobacteria genome) or PCR-amplified DNA (which origins from a template DNA strand that has been extracted from Mycobacterium avium paratuberculosis-spiked human sputum samples), respectively. Sensor responses up to 41 mV have been measured for the test solutions with DNA, while only small signals of ∼5 mV were detected for solutions without DNA. The lower detection limit of the EIS sensors was ∼0.3 nM, and the sensitivity was ∼7.2 mV/decade. Fluorescence experiments using SybrGreen I fluorescence dye support the electrochemical results.
Y1  - 2018
U6  - http://dx.doi.org/10.1021/acs.analchem.8b01807
SN  - 0003-2700
VL  - 90
IS  - 12
SP  - 7747
EP  - 7753
PB  - ACS Publications
CY  - Washington, DC
ER  -