TY  - JOUR
A1  - Wendlandt, Tim
A1  - Koch, Claudia
A1  - Britz, Beate
A1  - Liedek, Anke
A1  - Schmidt, Nora
A1  - Werner, Stefan
A1  - Gleba, Yuri
A1  - Vahidpour, Farnoosh
A1  - Welden, Melanie
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Facile Purification and Use of Tobamoviral Nanocarriers for Antibody-Mediated Display of a Two-Enzyme System
JF  - Viruses
N2  - Immunosorbent turnip vein clearing virus (TVCV) particles displaying the IgG-binding domains D and E of Staphylococcus aureus protein A (PA) on every coat protein (CP) subunit (TVCVPA) were purified from plants via optimized and new protocols. The latter used polyethylene glycol (PEG) raw precipitates, from which virions were selectively re-solubilized in reverse PEG concentration gradients. This procedure improved the integrity of both TVCVPA and the wild-type subgroup 3 tobamovirus. TVCVPA could be loaded with more than 500 IgGs per virion, which mediated the immunocapture of fluorescent dyes, GFP, and active enzymes. Bi-enzyme ensembles of cooperating glucose oxidase and horseradish peroxidase were tethered together on the TVCVPA carriers via a single antibody type, with one enzyme conjugated chemically to its Fc region, and the other one bound as a target, yielding synthetic multi-enzyme complexes. In microtiter plates, the TVCVPA-displayed sugar-sensing system possessed a considerably increased reusability upon repeated testing, compared to the IgG-bound enzyme pair in the absence of the virus. A high coverage of the viral adapters was also achieved on Ta2O5 sensor chip surfaces coated with a polyelectrolyte interlayer, as a prerequisite for durable TVCVPA-assisted electrochemical biosensing via modularly IgG-assembled sensor enzymes.
KW  - biosensor
KW  - horseradish peroxidase (HRP)
KW  - glucose oxidase (GOx)
KW  - enzyme cascade
KW  - turnip vein clearing virus (TVCV)
KW  - tobacco mosaic virus (TMV)
Y1  - 2023
U6  - http://dx.doi.org/doi.org/10.3390/v15091951
SN  - 1999-4915
N1  - This article belongs to the Special Issue "Tobamoviruses 2023"
VL  - 9
IS  - 15
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Rabner, Arthur
A1  - Shacham, Yosi
T1  - A concept for a sensitive micro total analysis system for high throughput fluorescence imaging
N2  - This paper discusses possible methods for on-chip fluorescent imaging for integrated bio-sensors. The integration of optical and electro-optical accessories, according to suggested methods, can improve the performance of fluorescence imaging. It can boost the signal to background ratio by a few orders of magnitudes in comparison to conventional discrete setups. The methods that are present in this paper are oriented towards building reproducible arrays for high-throughput micro total analysis systems (µTAS). The first method relates to side illumination of the fluorescent material placed into microcompartments of the lab-on-chip. Its significance is in high utilization of excitation energy for low concentration of fluorescent material. The utilization of a transparent µLED chip, for the second method, allows the placement of the excitation light sources on the same optical axis with emission detector, such that the excitation and emission rays are directed controversly. The third method presents a spatial filtering of the excitation background.
KW  - Biosensor
KW  - Fluorescence
KW  - imaging
KW  - lab-on-chip
KW  - fluidic
KW  - lenslet array
KW  - LED chip
KW  - image sensor
KW  - biosensor
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1456
ER  - 
TY  - CHAP
A1  - Lei, Yu
A1  - Mulchandani, Priti
A1  - Chen, Wilfred
A1  - Mulchandani, Ashok
T1  - Biosensor for direct determination of fenitrothion and EPN using recombinant Pseudomonas putida JS444 with surface expressed organophosphorus hydrolase. 1. modified clark oxygen electrode
N2  - This paper reports a first microbial biosensor for rapid and cost-effective determination of organophosphorus pesticides fenitrothion and EPN. The biosensor consisted of recombinant PNP-degrading/oxidizing bacteria Pseudomonas putida JS444 anchoring and displaying organophosphorus hydrolase (OPH) on its cell surface as biological sensing element and a dissolved oxygen electrode as the transducer. Surfaceexpressed OPH catalyzed the hydrolysis of fenitrothion and EPN to release 3-methyl-4-nitrophenol and p-nitrophenol, respectively, which were oxidized by the enzymatic machinery of Pseudomonas putida JS444 to carbon dioxide while consuming oxygen, which was measured and correlated to the concentration of organophosphates. Under the optimum operating conditions, the biosensor was able to measure as low as 277 ppb of fenitrothion and 1.6 ppm of EPN without interference from phenolic compounds and other commonly used pesticides such as carbamate pesticides, triazine herbicides and organophosphate pesticides without nitrophenyl substituent. The applicability of the biosensor to lake water was also demonstrated.
KW  - Biosensor
KW  - Organophosphorus
KW  - fenitrothion
KW  - EPN
KW  - biosensor
KW  - Pseudomonas putida
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1573
ER  -