An improved synthetic method has been designed and demonstrated to reproducibly generate hollow gold nanospheres (HGNs) with strong surface plasmon resonance (SPR) absorption in the near infrared (NIR). The HGNs have been synthesized via galvanic replacement of cobalt with gold while utilizing different amounts of poly(vinylpyrrolidone) (PVP) as a template stabilizing agent. Ninety percent of syntheses performed by this modified method resulted in HGNs with an SPR near 800 nm, which is highly desirable for biomedical applications such as photothermal ablation (PTA) therapy, while other polymers (PAA and PEG) did not. Based on absorption and TEM measurements, PVP stabilizes the cobalt template particles via carbonyl-induced stabilization that slows nucleation and growth of the gold shell allowing for the generation of a reproducibly thin shell, thereby inducing a significant red shift of the SPR to 800 nm. The results are significant to various potential applications of HGNs, e.g. cancer therapy and sensing.

Facile and reproducible SERS signals from Shewanella oneidensis were obtained utilizing silver nanoparticles (AgNPs) and silver nanowires (AgNWs). Additionally, SERS images identify the distribution of SERS hot-spots. One important observation is the synergistically enhanced SERS signal when AgNPs and AgNWs are used in conjunction, due to constructively enhanced electromagnetic field.

It is known that room temperature beta‐irradiated Ib type diamond generates a non‐reproducible TL glow curve shape, due to mobility of the impurity‐vacancy (I –V) and interstitials (I) defects in the 30–800 °C temperature range. This situation may hinder the use of this type of diamond material in dose assessment applications. The recurring heating of the Ib type diamond sample changes the defects concentration and consequently the intensity of the TL glow peaks associated to the characteristic temperature annealing stages. In the present work we have performed thermal annealing (TA) treatment on an Ib type diamond in the 100–800 °C range previous to beta irradiation. It was observed that after the 800 °C annealing treatment the TL glow curve showed 3–5% reproducibility, in contrast to the non‐reproducible TL observed in non‐annealed diamond, and remained the same after two months of successive TL read outs. Moreover, the 800 °C annealing treatment assured a linear integrated TL dose behavior, a significant improvement over non‐annealed samples that could facilitate the employment of Ib type synthetic diamond in dosimetric applications. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Afterglow (AG) and thermoluminescence (TL) of CVD diamond UV‐irradiated with wavelength of 200–260 nm at room temperature are reported. The AG curves monotonously decrease with time and are fitted well by the hyperbolic law. The decay times depends on UV wavelength and decreases with the AG intensity increasing. The TL glow curves exhibit two pronounced TL peaks with maxima at about 350 K and 513 K with unstructured signal between them and are fitted well by four TL peaks. The first, 350 K peak with the activation energy of 0.59 eV was supposed to be second kinetics order. The higher temperature peaks at 402 K, 445 K and 513 K with the activation energies of 0.46 eV, 0.49 eV and 0.68 eV, respectively were assumed to be first kinetics order. The comparison of the AG decay times with the kinetics parameters of the 350 K TL peak proved that AG is caused by thermal emptying of the traps responsible for the 350 K peak. The behaviour of AG and 350 K TL peak was described by the model, in which shallow traps, recombination centers and deep thermally disconnected traps are taken into account. The AG and TL creation spectra are practically the same and consists of a broad band, which exponentially increases from 260 nm, reaches a maximum at 240 nm and then begins decreasing. The creation spectra of the AG and TL peaks are the same and closely related with the fundamental absorption of UV light near indirect band gap of diamond. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The behaviour of afterglow (AG), thermoluminescence (TL) and infrared-stimulated luminescence (IRSL) in beta-irradiated chemical vapour deposition diamond is presented. The TL glow curve consists of four peaks with maxima at about 380, 430, 530 and 610 K. The AG decay is fitted by Becquerel's law with exponent close to 1, and correlates well with the thermal emptying of the traps responsible for the 380 K peak. Stimulation with IR light (830 nm) creates intense IRSL and destroys the 380, 430 and 530 K peaks. Illumination with shorter wavelength light also destroys the 610 K peak. The thermal cleaning procedure removes subsequently TL peaks, AG and IRSL. The AG signal decays together with the disappearance of the 380 K peak. The IRSL signal decays continuously with the removal of the 380, 430 and 530 K peaks. Traps responsible for the 610 K peak do not participate in the IRSL process.