Doping with biomolecules

Recently, PT and its derivatives have also been proved promising for tissue engineering. This class of polymers shows excellent biocompatibility and biodegradability. However, PEDOT so far has been the most successful, with its higher conductivity and stability and ion diffusion capacity [250,251]. Like PPy and PANI, PEDOT has also been modified for enhancing properties and doped with biomolecules like NGE for specific bioapplications. 

The applicability of DNP to biomolecules in the solid state was first demonstrated using lysozyme in a frozen glycerol/water matrix doped with TEMPO monoradicals. In this study, helium gas cooled to 40 K served as bearing and drive gas for MAS [219]. Subsequently, hyperpolarization by DNP has successfully been applied to a virus particle [220], to multidimensional heteronuclear spectroscopy of protein microcrystals of amyloidogenic peptides [221], and to a membrane receptor trapped in different stages of the photocycle [176, 177, 222]. 

S. Santra, P. Zhang, K.M. Wang, R. Tapec, and W.H. Tan, Conjugation of biomolecules with lumino-phore-doped silica nanoparticles for photostable biomarkers. Anal. Chem. 73, 4988-4993 (2001). 

The fast, sensitive, reliable, and reproducible detection of (bio)molecules including quantification as well as biomolecule localization, the measurement of their interplay with one another or with other species, and the assessment of biomolecule function in bioassays as well as in vitro and in vivo plays an ever increasing role in the life sciences. The vast majority of applications exploit extrinsic fluorophores like organic dyes, fluorescent proteins, and also increasingly QDs, as the number of bright intrinsic fluorophores emitting in the visible and NIR is limited. In the near future, the use of fluorophore-doped nanoparticles is also expected to constantly increase, with their applicability in vivo being closely linked to the intensively discussed issue of size-related nanotoxicity [88]. 

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