TY  - JOUR
A1  - Dutta, Anushree
A1  - Schürmann, Robin Mathis
A1  - Balko, Ilko
T1  - Plasmon mediated decomposition of brominated nucleobases on silver nanoparticles
BT  - a surface enhanced Raman scattering (SERS) study
JF  - The european physical journal D
N2  - The localized surface plasmon resonances (LSPRs) of silver nanoparticles (AgNPs) give rise to the generation of so called hot electrons and a high local electric field enhancement, which enable an application of AgNPs in different fields ranging from catalysis to sensing. Hot electrons generated upon the decay of LSPRs are transferred to molecules adsorbed on the surface of the NPs and trigger chemical reactions via dissociative electron attachment (DEA). Herein, we report on the hot electron induced decomposition of the brominated nucleobases – 8-bromoadenine, 8-bromoguanine, 5-bromocytosine and 5-bromouracil on laser illuminated AgNP surfaces. Surface enhanced Raman scattering (SERS) spectra of all canonical nucleobases and their brominated analogues have been recorded at different laser illumination times, and for the very first time we present SERS measurements of 8-bromoguanine and 5-bromocytosine. Reaction products have been identified by their vibrational fingerprint revealing the cleavage of the carbon bromide bond in all cases even under mild illumination conditions. These results indicate that the well-known reactions from DEA experiments in the gas phase (i) are also taking place on nanoparticle surfaces under ambient conditions, (ii) can be monitored by SERS, and (iii) are also of importance in analytical SERS applications involving electrophilic molecules, as the bands originating from reaction products need to be identified.
Y1  - 2020
UR  - https://link.springer.com/article/10.1140/epjd/e2019-100115-1
U6  - https://doi.org/10.1140/epjd/e2019-100115-1
SN  - 1434-6079
SN  - 1434-6060
VL  - 74
IS  - 19
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Schürmann, Robin Mathis
A1  - Luxford, Thomas
A1  - Vinklárek, Ivo
A1  - Kočišek, Jaroslav
A1  - Zawadzki, Mateusz
A1  - Balko, Ilko
T1  - Interaction of 4-nitrothiophenol with low energy electrons
BT  - implications for plasmon mediated reactions
JF  - Journal of chemical physics
N2  - The reduction of 4-nitrothiophenol (NTP) to 4-4′-dimercaptoazobenzene (DMAB) on laser illuminated noble metal nanoparticles is one of the most widely studied plasmon mediated reactions. The reaction is most likely triggered by a transfer of low energy electrons from the nanoparticle to the adsorbed molecules. Besides the formation of DMAB, dissociative side reactions of NTP have also been observed. Here, we present a crossed electron-molecular beam study of free electron attachment to isolated NTP in the gas-phase. Negative ion yields are recorded as a function of the electron energy, which helps to assess the accessibility of single electron reduction pathways after photon induced electron transfer from nanoparticles. The dominant process observed with isolated NTP is associative electron attachment leading to the formation of the parent anion of NTP. Dissociative electron attachment pathways could be revealed with much lower intensities, leading mainly to the loss of functional groups. The energy gained by one electron reduction of NTP may also enhance the desorption of NTP from nanoparticles. Our supporting experiments with small clusters, then, show that further reaction steps are necessary after electron attachment to produce DMAB on the surfaces.
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?https://aip.scitation.org/doi/10.1063/5.0018784
SN  - 1089-7690
SN  - 0021-9606
VL  - 153
SP  - 104303
PB  - American Institute of Physics
CY  - Melville
ER  -