@article{ZhaoYueZhuetal.2024, author = {Zhao, Shuang and Yue, Zhao and Zhu, Dingcheng and Harberts, Jann and Blick, Robert H. and Zierold, Robert and Lisdat, Fred and Parak, Wolfgang J.}, title = {Quantum Dot/TiO2 Nanocomposite-Based Photoelectrochemical Sensor for Enhanced H2O2 Detection Applied for Cell Monitoring and Visualization}, series = {Small}, volume = {20}, journal = {Small}, number = {45}, publisher = {Wiley}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-19642}, year = {2024}, abstract = {This work exploits the possibility of using CdSe/ZnS quantum dot (QD)-electrodes to monitor the metabolism of living cells based on photoelectrochemical (PEC) measurements. To realize that, the PEC setup is improved with respect to an enhanced photocurrent signal, better stability, and an increased signal-to-noise ratio, but also for a better biocompatibility of the sensor surface on which cells have been grown. To achieve this, a QD-TiO2 heterojunction is introduced with the help of atomic layer deposition (ALD). The heterojunction reduces the charge carrier recombination inside the semiconductor nanoparticles and improves the drift behavior. The PEC performance is carefully analyzed by adjusting the TiO2 thickness and combining this strategy with multilayer immobilizations of QDs. The optimal thickness of this coating is ≈5 nm; here, photocurrent generation can be enhanced significantly (e.g., for a single QD layer electrode by more than one order of magnitude at 0 V vs Ag/AgCl). The resulting optimized electrode is used for hydrogen peroxide (H2O2) sensing with a good sensitivity down to µmolar concentrations, reusability, stability, response rate, and repeatability. Finally, the sensing system is applied to monitor the activity of cells directly grown on top of the electrode surface.}, language = {en} } @article{ReunerHengherrMalietal.2010, author = {Reuner, Andy and Hengherr, Steffen and Mali, Brahim and F{\"o}rster, Frank and Arndt, Detlev and Reinhardt, Richard and Dandekar, Thomas and Frohme, Marcus and Br{\"u}mmer, Franz and Schill, Ralph O.}, title = {Stress response in tardigrades: differential gene expression of molecular chaperones}, series = {Cell Stress and Chaperones}, volume = {15}, journal = {Cell Stress and Chaperones}, number = {4}, publisher = {Springer}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-19994}, pages = {423 -- 430}, year = {2010}, abstract = {Semi-terrestrial tardigrades exhibit a remarkable tolerance to desiccation by entering a state called anhydrobiosis. In this state, they show a strong resistance against several kinds of physical extremes. Because of the probable importance of stress proteins during the phases of dehydration and rehydration, the relative abundance of transcripts coding for two α-crystallin heat-shock proteins (Mt-sHsp17.2 and Mt-sHsp19.5), as well for the heat-shock proteins Mt-sHsp10, Mt-Hsp60, Mt-Hsp70 and Mt-Hsp90, were analysed in active and anhydrobiotic tardigrades of the species Milnesium tardigradum. They were also analysed in the transitional stage (I) of dehydration, the transitional stage (II) of rehydration and in heat-shocked specimens. A variable pattern of expression was detected, with most candidates being downregulated. Gene transcripts of one Mt-hsp70 isoform in the transitional stage I and Mt-hsp90 in the anhydrobiotic stage were significantly upregulated. A high gene expression (778.6-fold) was found for the small α-crystallin heat-shock protein gene Mt-sHsp17.2 after heat shock. We discuss the limited role of the stress-gene expression in the transitional stages between the active and anhydrobiotic tardigrades and other mechanisms which allow tardigrades to survive desiccation.}, language = {en} }