Heterogeneous samples of spiral ganglion neuron primary cells were incubated with gold nanorods in order to investigate
the photothermal processes induced by exposure to 780 nm laser light. Dark-field microspectroscopy was used to
analyze the distribution and spectrum of nanorods in the neurons. The scattering data showed a typical gold nanorod
spectrum, while a shift in the peak position suggested changes in the refractive index of the nanorod environment. The
relationship between gold nanorods distribution and local temperature has also been examined with an open pipette
microelectrode placed in the surrounding bath of the neurons. These temperature measurements confirm that the gold
nanorods provide efficient localized heating under 780 nm laser exposure.
Hybrid thin films of multi-walled carbon nanotube (MWCNT) and titania were fabricated on quartz slides by
alternatively depositing MWCNT and titanium(IV) bis(ammonium lactato) dihydroxide (TALH) via a solution based
layer-by-layer (LbL) self-assembly method followed by calcination to convert TALH to crystalline titania. The
multilayer film build-up was monitored by UV-vis spectroscopy which indicated the linear growth of the film with the
bilayer number. XRD confirmed the formation of anantase titania after heat treatment. The photocatalytic property of
the hybrid thin film was evaluated by its capacity to degrade rhodamine B under the UV illumination. Compared with
pure TiO<sub>2</sub> film, experiments showed that the MWCNT/TiO<sub>2</sub> hybrid film had a much higher photocatalytic activity
under the same conditions. The first order rate constant of photocatalysis of 30 bilayers of hybrid film was
approximately 8-fold higher than that of 30 bilayers of pure TiO<sub>2</sub> film. In addition, the degradation efficiency of
MWCNT/TiO<sub>2</sub> hybrid thin film increased with its thickness while pure titania film remained unchanged. A 30 bilayers
hybrid thin film that contains about 0.2 mg MWCNT/TiO<sub>2</sub> catalyst was capable of completely degrading 10 mL of 2
mg/L Rh B solution within 5 hours. The results also indicated that the hybrid catalyst could be reused for several cycles.
As-synthesized, poly(4-styrenesulfonic acid) (PSS)-coated and SiO<sub>2</sub> coated gold nanorods were taken up by NG108-15 neuronal cells. Exposure to laser light at the plasmon resonance wavelength of gold nanorods was found to trigger the differentiation process in the nanoparticle treated cells. Results were assessed by measuring the maximum neurite length, the number of neurites per neuron and the percentage of neurons with neurites. When the intracellular Ca<sup>2+</sup> signaling was monitored, evidence of photo-generated transients were recorded without altering other normal cell functions. These results open new opportunities for peripheral nerve regeneration treatments and for the process of infrared nerve stimulation.