Mechanistic studies into the Raman enhancement of enediol-semiconducting nanoparticle conjugates and their use in biological applications

Hurst, Sarah J.; Fry, H. Christopher; Gosztola, David J.; Finkelstein-Shapiro, Daniel; Mújica, Vladimiro; Rajh, Tijana

doi:10.1117/12.862931

Cited by 1 publication

(3 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spherical NPs that are used in this work present a diameter of 2.2 nm, similar to those used in several works of NP + linker (dopamine or DOPAC) complexation. ,,,,,− , Experimental characterization of this type of NP was obtained by XANES spectroscopy . Four-, five-, and six-fold coordinated Ti atoms were identified according to the position and the intensity of the pre-edge peaks.…”

Section: Results and Discussionmentioning

confidence: 99%

“…The absorption spectrum of the DOPAC/TiO 2 NP complex is characterized by an absorption onset shift up to 800 nm. , We present the computed electronic properties for the most stable DOPAC adsorption configuration B 11,9 C 12 on the spherical nanoparticle in terms of total and projected DOS in Figure : panel (d) is from DFTB, panel (e) is from DFT/DFTB, and panel (f) is from DFT calculations, in analogy to what was discussed for dopamine in Section . We observe very similar features to dopamine, with the same number of peaks in the TiO 2 band gap that are assigned to the DOPAC molecule fragment (see plots in Figure ).…”

Section: Results and Discussionmentioning

confidence: 99%

“…The size of the real TiO 2 nanoparticles used in the experiments is similar to that of the simulated systems. The experimental findings are mainly based on spectrophotometric measurements, electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), X-ray absorption measurements (XANES and EXAFS), infrared (IR), and surface-enhanced Raman spectroscopy (SER). ,,,,,− …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Unraveling Dynamical and Light Effects on Functionalized Titanium Dioxide Nanoparticles for Bioconjugation

et al. 2019

View full text Add to dashboard Cite

Functionalizing nanoparticles (NPs) with biological molecules is a promising modern strategy in bionanotechnology to build up smart bioinorganic devices for medical applications. Bifunctional linkers provide an interesting and ductile bioconjugation approach especially because they behave not only as anchoring and tethering agents but also as spacers between the NP and the biomolecules, which helps in maintaining their 3D structural and functional properties. In this work, by means of a wide set of density functional theory (DFT) electronic structure calculations and density functional tight binding (DFTB) molecular dynamics simulations, we provide an all-round investigation of the functionalization of realistic curved TiO2 NPs (2–3 nm size with ∼800 atoms) with a catechol derivative, such as dopamine and DOPAC. We span from single-molecule adsorption to the full coverage regime. For the low coverage, we achieve a detailed description of the mechanisms of molecular adsorption, of the interfacial electronic charge-transfer effects, and of the processes following visible light irradiation (exciton formation, trapping, charge carrier diffusion, or recombination). We then consider a growing molecular layer on the NP and analyze the self-assembling mechanism and the effects on the electronic properties of the complex. Finally, for the maximum coverage (46 molecules per NP) we perform molecular dynamics runs at 300 K to compare the molecular configuration and electronic properties of the NP/linker complex interface before and after thermal treatment to better account for the competition between molecule/surface and molecule/molecule interactions. The use of curved NP surfaces combined with dopamine, with respect to a flat one and DOPAC, respectively, is found to be more effective for bioconjugation.

show abstract