查看更多>>摘要：Although magnetism undoubtedly influences life on Earth,the science behind biological magnetic sensing is largely a mystery,and it has proved challenging,especially in the life sciences,to harness the interactions of magnetic fields(MFs)with matter to achieve specific ends.Using the well-established radical pair(RP)mechanism,we here demonstrate a bottom-up strategy for the exploitation of MF effects in living cells by translating knowledge from studies of RP reactions performed in vitro.We found an unprecedented MF dependence of the reactivity of singlet oxygen(1O2)towards electron-rich substrates(S)such as anthracene,lipids and iodide,in which[S·+O2·-]RPs are formed as a basis for MFs influencing molecular redox events in biological systems.The close similarity of the observed MF effects on the biologically relevant process of lipid peroxidation in solution,in membrane mimics and in living cells,shows that MFs can reliably be used to manipulate1 O2-induced cytotoxicity and cell-apoptosis-related protein expression.These findings led to a'proof-of-concept'study on MF-assisted photodynamic therapy in vivo,highlighting the potential of MFs as a non-invasive tool for controlling cellular events.
查看更多>>摘要：The chiral-induced spin selectivity(CISS)effect offers promising prospects for spintronics,yet designing chiral materials that enable efficient spin-polarized electron transport remains challenging.Here,we report the utility of covalent organic frameworks(COFs)in manipulating electron spin for spin-dependent catalysis via CISS.This enables us to design and synthesize three three-dimensional chiral COFs(CCOFs)with tunable electroactivity and spin-electron conductivity through imine condensations of enantiopure 1,1'-binaphthol-derived tetraaldehyde and tetraamines derived from 1,4-benzenediamine,pyrene,or tetrathiafulvalene skeletons.The CISS effect of CCOFs is verified by magnetic conductive atomic force microscopy.Compared with their achiral analogs,these CCOFs serve as efficient spin filters,reducing the overpotential of oxygen evolution and improving the Tafel slope.Particularly,the diarylamine-based CCOF showed a low overpotential of430 mV(vs reversible hydrogen electrode)at 10 mA cm-2 with long-term stability comparable to the commercial RuO2.This enhanced spin-dependent OER activity stems from its excellent redox-activity,good electron conductivity and effective suppression effect on the formation of H2O2 byproducts.
Brian P.BloomZhongwei ChenHaipeng LuDavid H.Waldeck...
33-46页
查看更多>>摘要：This review discusses opportunities in chemistry that are enabled by the chiral induced spin selectivity(CISS)effect.First,the review begins with a brief overview of the seminal studies on CISS.Next,we discuss different chiral material systems whose properties can be tailored through chemical means,with a special emphasis on hybrid organic-inorganic layered materials that exhibit some of the largest spin filtering properties to date.Then,we discuss the promise of CISS for chemical reactions and enantioseparation before concluding.
查看更多>>摘要：The spin of electrons plays a vital role in chemical reactions and processes,and the excited state generated by the absorption of photons shows abundant spin-related phenomena.However,the importance of electron spin in photochemistry studies has been rarely mentioned or summarized.In this review,we briefly introduce the concept of spin photochemistry based on the spin multiplicity of the excited state,which leads to the observation of various spin-related photophysical properties and photochemical reactivities.Then,we focus on the recent advances in terms of light-induced magnetic properties,excited-state magneto-optical effects and spin-dependent photochemical reactions.The review aims to provide a comprehensive overview to utilize the spin multiplicity of the excited state in manipulating the above photophysical and photochemical processes.Finally,we discuss the existing challenges in the emerging field of spin photochemistry and future opportunities such as smart magnetic materials,optical information technology and spin-enhanced photocatalysis.
查看更多>>摘要：Hyperpolarization stands out as a technique capable of significantly enhancing the sensitivity of nuclear magnetic resonance(NMR)and magnetic resonance imaging(MRI).Dynamic nuclear polarization(DNP),among various hyperpolarization methods,has gained prominence for its efficacy in real-time monitoring of metabolism and physiology.By administering a hyperpolarized substrate through dissolution DNP(dDNP),the biodistribution and metabolic changes of the DNP agent can be visualized spatiotemporally.This approach proves to be a distinctive and invaluable tool for non-invasively studying cellular metabolism in vivo,particularly in animal models.Biomarkers play a pivotal role in influencing the growth and metastasis of tumor cells by closely interacting with them,and accordingly detecting pathological alterations of these biomarkers is crucial for disease diagnosis and therapy.In recent years,a range ofhyperpolarized DNP molecular bioresponsive agents utilizing various nuclei,such as 13C,15N,31P,89Y,etc.,have been developed.In this context,we explore how these magnetic resonance signals of nuclear spins enhanced by DNP respond to biomarkers,including pH,metal ions,enzymes,or redox processes.This review aims to offer insights into the design principles of responsive DNP agents,target selection,and the mechanisms of action for imaging.Such discussions aim to propel the future development and application of DNP-based biomedical imaging agents.
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