scholarly journals Functional CdS-Au Nanocomposite for Efficient Photocatalytic, Photosensitizing, and Two-Photon Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 715
Author(s):  
Katarzyna C. Nawrot ◽  
Dominika Wawrzyńczyk ◽  
Oleksii Bezkrovnyi ◽  
Leszek Kępiński ◽  
Bartłomiej Cichy ◽  
...  

We demonstrate a low-temperature synthesis of hydrophilic, penicillamine-stabilized hybrid CdS-Au nanoparticles (NPs) utilizing different Au concentrations. The obtained hybrid nanomaterials exhibit photoluminescence quenching and emission lifetime reduction in comparison with their raw semiconductor CdS NPs counterparts. An increase of concentration of Au present at the surface of CdS leads to lower photoluminescence intensity and faster emission decays, suggesting more efficient charge separation when larger Au domains are present. For photocatalysis studies, we performed methylene blue (MB) absorption measurements under irradiation in the presence of CdS-Au NPs. After 1 h of light exposure, we observed the absorbance decrease to about 35% and 10% of the initial value for the CdS-5Au and CdS-7.5Au (the hybrid NPs obtained in a presence of 5.0 and 7.5 mM Au), respectively, which indicates MB reduction caused by electrons effectively separated from holes on metal surface. In further similar photocatalysis experiments, we measured bovine serum albumin (BSA) integrated photoluminescence intensity quenching in the presence of CdS-Au NPs, with a 50% decrease being obtained for CdS-2.5Au NPs and CdS-5Au NPs, with a faster response rate detected for the system prepared with a higher Au concentration. The results suggest hole-driven reactive oxygen species (ROS) production, causing BSA degeneration. Finally, we performed two-photon excited emission (TPEE) measurements for CdS-5Au NPs, obtaining their two-photon absorption (TPA) cross-section values up to 15.8 × 103 GM (Goeppert-Mayer units). We conclude that the obtained water-soluble CdS-Au NPs exhibit potential triple functionalities as photocatalysts for reduction and oxidation reactions as well as materials for two-photon absorption applications, so that they may be considered as future theranostics.

2007 ◽  
Vol 11 (06) ◽  
pp. 406-417 ◽  
Author(s):  
Yusuke Inaba ◽  
Kazuya Ogawa ◽  
Yoshiaki Kobuke

Acetylene-bridged bisporphyrins and trisporphyrins having branched bulky bis(carboxylethyl)methyl meso-substituents were synthesized. These compounds showed large effective two-photon absorption cross-section values at 890 nm measured by using a nanosecond Z-scan method. Sodium salt of hydrolyzed trisporphyrins showed broad and red-shifted Q-bands over 900 nm. Two-photon absorption cross-section values of water-soluble dimers in water were similar to, or slightly larger than, those of ester forms evaluated in toluene. Furthermore, the generation of singlet oxygen upon one-photon irradiation for dimers in water was confirmed.


2017 ◽  
Vol 5 (7) ◽  
pp. 1724-1729 ◽  
Author(s):  
D. Wawrzyńczyk

Synthesized penicillamine stabilized CdS tetrapods showed two-photon absorption in a wavelength range between 600 and 850 nm, and strong two-photon excited emission upon near infrared excitation. These water soluble colloidal, semiconducting nanoparticles show potential for applications in nonlinear bioimaging.


2005 ◽  
Vol 871 ◽  
Author(s):  
Han Young Woo ◽  
Dmitry Korystov ◽  
Alexander Mikhailovsky ◽  
Guillermo C. Bazan

AbstractA series of tetradonor substituted [2.2]paracyclophane-based two-photon absorption (TPA) fluorophores were designed, synthesized and characterized. Different substituents were chosen to modulate the conjugation and the donor strength and to allow the molecules to be neutral (N series, organic-soluble) or charged (C series, water-soluble). The overall set of compounds series allows us to examine the correlation among the solvent polarity, donor ability of the substituents, and TPA action cross section (ηδd, where δ is the TPA cross section and η is the quantum yield). In water, a significant drop of both δ and η is observed, approximately one-third relative to those in toluene. Weaker donors and/or weaker acceptors with enhanced conjugation are a better choice due to a minimized quenching related to strong charge transfer (CT) upon excitation. One thus needs to fine-tune the magnitude of CT and find an optimal balance among CT,δ and η.


2006 ◽  
Vol 49 (7) ◽  
pp. 2276-2283 ◽  
Author(s):  
Kazuya Ogawa ◽  
Hideki Hasegawa ◽  
Yusuke Inaba ◽  
Yoshiaki Kobuke ◽  
Hideyuki Inouye ◽  
...  

2013 ◽  
Vol 4 (7) ◽  
pp. 2833 ◽  
Author(s):  
Julien Massin ◽  
Azzam Charaf-Eddin ◽  
Florence Appaix ◽  
Yann Bretonnière ◽  
Denis Jacquemin ◽  
...  

RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 20068-20075 ◽  
Author(s):  
Qiong Zhang ◽  
Rongting Guan ◽  
Xiaohe Tian ◽  
Lei Luo ◽  
Hongping Zhou ◽  
...  

Two imidazole–pyrimidine hexafluorophosphate derivatives (6P and 10P) are synthesized. The 2PA cross-section values (σ) were obtained by Z-scan and two-photon excited fluorescence methods. 6P and 10P can be used to quantify and image organelles in living cells and tissues.


2013 ◽  
Vol 99 (3) ◽  
pp. 1051-1055 ◽  
Author(s):  
Haibo Xiao ◽  
Chong Mei ◽  
Bo Li ◽  
Ning Ding ◽  
Yanzhen Zhang ◽  
...  

Langmuir ◽  
2013 ◽  
Vol 29 (35) ◽  
pp. 11005-11012 ◽  
Author(s):  
Yuanwei Zhang ◽  
Bosung Kim ◽  
Sheng Yao ◽  
Mykhailo V. Bondar ◽  
Kevin D. Belfield

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