Aryl ketones as photolabile protecting group(PPG)to modify purine imines is a novel nucleic acid protection strategy.Especially,photoprotection of N7-guanosine is the first reported photoprotected nucleoside that can ...Aryl ketones as photolabile protecting group(PPG)to modify purine imines is a novel nucleic acid protection strategy.Especially,photoprotection of N7-guanosine is the first reported photoprotected nucleoside that can affect the Hoogsteen recognition site of guanosine.However,the mechanism,which is pivotal to high efficiency of photorelease and applications of PPGs in biological and medical systems,is unclear.Here,a detailed deprotection mechanism of benzophenone protected guanosine(BP-Guo)at N7 position is reported.Upon irradiation,BP-Guo populates to singlet state,which generates^(3)[BP]-Guo via intersystem crossing process.Thereafter,triplet energy transfer competes with hydrogen atom transfer forming BP-^(3)[Guo]and ketyl-Guo,respectively.Both species break C–N bond to release guanosine.These results provide deeper insights into exploiting improved strategies for photo-protecting nucleic acids.In particular,the TTET pathway could trigger well-known cyclization reactions that brings about DNA mutagenic adducts.The latter should be avoided in developing improved strategies for photoprotecting nucleic acids.展开更多
The properties of the triplet excited state of [60]fullerene-containing cyclic sulphoxide have been investigated by time-resolved absorption spectroscopy. Transient absorption bands of [60]fullerene-containing cyclic...The properties of the triplet excited state of [60]fullerene-containing cyclic sulphoxide have been investigated by time-resolved absorption spectroscopy. Transient absorption bands of [60]fullerene-containing cyclic sulphoxide showed two decay-components, which were attributed to triplet excited states of different spin multiplicity. The properties of photoexcited states of [60]fullerene-containing cyclic sulphoxide are also reported.展开更多
Over the past decade the integration of ultrafast spectroscopy with nanoscience has greatly propelled the development of nanoscience, as the key information gleaned from the mechanistic studies with the assistance of ...Over the past decade the integration of ultrafast spectroscopy with nanoscience has greatly propelled the development of nanoscience, as the key information gleaned from the mechanistic studies with the assistance of ultrafast spectroscopy enables a deeper understanding of the structure–function interplay and various interactions involved in the nanosystems.This mini-review presents an overview of the recent advances achieved in our ultrafast spectroscopy laboratory that address the ultrafast dynamics and related mechanisms in several representative nanomaterial complex systems by means of femtosecond time-resolved transient absorption spectroscopy. We attempt to convey instructive, consistent information regarding the important processes, pathways, dynamics, and interactions involved in the nanomaterial complex systems,most of which exhibit excellent performance in photocatalysis.展开更多
Indoor organic photovoltaic(OPV)cells have emerged as promising candidates for harvesting energy from artificial light sources.However,the limited spectral range and low photon flux of indoor light sources restrict th...Indoor organic photovoltaic(OPV)cells have emerged as promising candidates for harvesting energy from artificial light sources.However,the limited spectral range and low photon flux of indoor light sources restrict the photocurrent and power output of thesedevices.In this work,we investigate the role of a weak absorptive third component in enhancing exciton dissociation and improvingindoor OPV performance.By introducing eC9-20l into a D18-Cl:F-BTA3 binary system,we create a ternary blend that demonstratessignificant improvements in device efficiency.Transient absorption spectroscopy and time-resolved photoluminescence measure-ments reveal that eC9-2Cl facilitates efficient energy transfer and exciton dissociation.Under indoor lighting conditions,where eC9-2clacts as a weak absorptive third component,the ternary devices exhibit a power conversion efficiency increase from 24.7%to 26.2%.These findings highlight the potential of weak absorptive components in optimizing energy transfer processes and overcoming thelimitations of indoor light harvesting in OPV systems.展开更多
Localized surface plasmon resonance(LSPR)effects in gold nanoparticles(AuNPs)significantly influence the excited states of nearby molecules,offering unique opportunities for enhancing molecular triplet states.Herein,w...Localized surface plasmon resonance(LSPR)effects in gold nanoparticles(AuNPs)significantly influence the excited states of nearby molecules,offering unique opportunities for enhancing molecular triplet states.Herein,we report the synthesis of DNA-templated gold nanostars(AuNF_A15)and gold nanospheres(AuNS_T15)via a seed-mediated growth method and their ability to enhance the triplet state of coralyne,a small molecule with promising applications in photodynamic therapy(PDT).DNA single strands(A15 or T15)were employed as templates to regulate the morphology of AuNPs,resulting in nanostars and nanospheres.The nanostars exhibited a superior LSPR effect due to their“lightning rod effect",significantly enhancing coralyne’s triplet signal by 15-fold compared to a 10-fold enhancement observed with nanospheres.This enhancement was confirmed via steady-state and nanosecond transient absorption spectroscopy.These findings demonstrate that DNA-assembled gold nanostars hold exceptional potential for enhancing molecular triplet states,particularly for PDT applications involving DNA-targeting small molecules.展开更多
Sub-microsecond time-resolved absorption spectroscopy has been used to study the electronically excited state behavior of soluble multiwalled carbon nanotube (MWNTsCON((CH2)9- CH3)2, denoted as MDDA) in chloroform, to...Sub-microsecond time-resolved absorption spectroscopy has been used to study the electronically excited state behavior of soluble multiwalled carbon nanotube (MWNTsCON((CH2)9- CH3)2, denoted as MDDA) in chloroform, toluene and cyclohexane. Following pulsed photo-excitation of MDDA at 355 nm, three major spectral components are clearly identified with the help of global analysis carried out over 7 representative kinetics curves from 450 to 700 nm. The solvent depend-ence of decay associated difference spectra (DADS) and the corresponding lifetimes help to assign these transient species to singlet state (S1), triplet state (T1) and charge-separated state (CS), re-spectively. Preliminary discussion had been made to explore the involved photophysical and electron transfer processes.展开更多
基金sponsored by grants from the National Natural Science Foundation of China(Nos.22322301,22303046)the Shaanxi Science Fund for Distinguished Young Scholars(No.2021JC-38)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.GK202207001,GK202304008)the Shaanxi Province Postdoctoral Science Foundation(No.2023BSHEDZZ187).
文摘Aryl ketones as photolabile protecting group(PPG)to modify purine imines is a novel nucleic acid protection strategy.Especially,photoprotection of N7-guanosine is the first reported photoprotected nucleoside that can affect the Hoogsteen recognition site of guanosine.However,the mechanism,which is pivotal to high efficiency of photorelease and applications of PPGs in biological and medical systems,is unclear.Here,a detailed deprotection mechanism of benzophenone protected guanosine(BP-Guo)at N7 position is reported.Upon irradiation,BP-Guo populates to singlet state,which generates^(3)[BP]-Guo via intersystem crossing process.Thereafter,triplet energy transfer competes with hydrogen atom transfer forming BP-^(3)[Guo]and ketyl-Guo,respectively.Both species break C–N bond to release guanosine.These results provide deeper insights into exploiting improved strategies for photo-protecting nucleic acids.In particular,the TTET pathway could trigger well-known cyclization reactions that brings about DNA mutagenic adducts.The latter should be avoided in developing improved strategies for photoprotecting nucleic acids.
文摘The properties of the triplet excited state of [60]fullerene-containing cyclic sulphoxide have been investigated by time-resolved absorption spectroscopy. Transient absorption bands of [60]fullerene-containing cyclic sulphoxide showed two decay-components, which were attributed to triplet excited states of different spin multiplicity. The properties of photoexcited states of [60]fullerene-containing cyclic sulphoxide are also reported.
基金support from the National Natural Science Foundation of China (21573211 and 21421063)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB01020200)the Fundamental Research Funds for the Central Universities of China (WK2340000063)
文摘Over the past decade the integration of ultrafast spectroscopy with nanoscience has greatly propelled the development of nanoscience, as the key information gleaned from the mechanistic studies with the assistance of ultrafast spectroscopy enables a deeper understanding of the structure–function interplay and various interactions involved in the nanosystems.This mini-review presents an overview of the recent advances achieved in our ultrafast spectroscopy laboratory that address the ultrafast dynamics and related mechanisms in several representative nanomaterial complex systems by means of femtosecond time-resolved transient absorption spectroscopy. We attempt to convey instructive, consistent information regarding the important processes, pathways, dynamics, and interactions involved in the nanomaterial complex systems,most of which exhibit excellent performance in photocatalysis.
基金supported by the Shandong Provincial Natural Science Foundation(Nos.ZR2022QF123,ZR2023QA101)J.W.Q.thanks the Postdoctoral Fellowship Program of CPSF(No.GZC20231485).
文摘Indoor organic photovoltaic(OPV)cells have emerged as promising candidates for harvesting energy from artificial light sources.However,the limited spectral range and low photon flux of indoor light sources restrict the photocurrent and power output of thesedevices.In this work,we investigate the role of a weak absorptive third component in enhancing exciton dissociation and improvingindoor OPV performance.By introducing eC9-20l into a D18-Cl:F-BTA3 binary system,we create a ternary blend that demonstratessignificant improvements in device efficiency.Transient absorption spectroscopy and time-resolved photoluminescence measure-ments reveal that eC9-2Cl facilitates efficient energy transfer and exciton dissociation.Under indoor lighting conditions,where eC9-2clacts as a weak absorptive third component,the ternary devices exhibit a power conversion efficiency increase from 24.7%to 26.2%.These findings highlight the potential of weak absorptive components in optimizing energy transfer processes and overcoming thelimitations of indoor light harvesting in OPV systems.
基金supported by the National Natural Science Foundation of China(Nos.21933005,22473014,and 22273007)the National Key R&D Program of China(No.2022YFA1505400).
文摘Localized surface plasmon resonance(LSPR)effects in gold nanoparticles(AuNPs)significantly influence the excited states of nearby molecules,offering unique opportunities for enhancing molecular triplet states.Herein,we report the synthesis of DNA-templated gold nanostars(AuNF_A15)and gold nanospheres(AuNS_T15)via a seed-mediated growth method and their ability to enhance the triplet state of coralyne,a small molecule with promising applications in photodynamic therapy(PDT).DNA single strands(A15 or T15)were employed as templates to regulate the morphology of AuNPs,resulting in nanostars and nanospheres.The nanostars exhibited a superior LSPR effect due to their“lightning rod effect",significantly enhancing coralyne’s triplet signal by 15-fold compared to a 10-fold enhancement observed with nanospheres.This enhancement was confirmed via steady-state and nanosecond transient absorption spectroscopy.These findings demonstrate that DNA-assembled gold nanostars hold exceptional potential for enhancing molecular triplet states,particularly for PDT applications involving DNA-targeting small molecules.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 20373079).
文摘Sub-microsecond time-resolved absorption spectroscopy has been used to study the electronically excited state behavior of soluble multiwalled carbon nanotube (MWNTsCON((CH2)9- CH3)2, denoted as MDDA) in chloroform, toluene and cyclohexane. Following pulsed photo-excitation of MDDA at 355 nm, three major spectral components are clearly identified with the help of global analysis carried out over 7 representative kinetics curves from 450 to 700 nm. The solvent depend-ence of decay associated difference spectra (DADS) and the corresponding lifetimes help to assign these transient species to singlet state (S1), triplet state (T1) and charge-separated state (CS), re-spectively. Preliminary discussion had been made to explore the involved photophysical and electron transfer processes.
