Chirality induced long-range spin-selective transport in helical 3D metal–organic frameworks Pravesh Singh Bisht, Rabia Garg, Tapan Kumar Das, Nidhi Bhatt, Subash Chandra Sahoo, et al. Chemical Science, 2026 In this study, we have demonstrated chirality induced long-range spin-selective transport in three-dimensional (3D) chiral metal–organic frameworks (MOFs) through the CISS effect.
Sevoflurane and Desflurane Spin–Decoherence Effect on Fe(III)acetylacetonate Redox Process Neha Kumari, Andrea Severini, Mauro Borghi, Monica Montecchi, Luca Pasquali, et al. Molecules, 2025 This study investigates the influence of sevoflurane and desflurane on the electrochemical behavior of the Fe(III)-acetylacetonate (Fe(acac)3) complex. Using cyclic voltammetry (CV), we demonstrate that while Fe(acac)3 exhibits reversible redox behavior in an oxygen-free environment, the presence of dissolved oxygen renders the system irreversible, leading to the formation of a thick, reddish film on the electrode surface upon potential cycling. Notably, the addition of sevoflurane and desflurane restores the electrochemical reversibility and dramatically inhibits this film formation. Raman spectroscopy of the resulting films confirmed structural changes which are consistent with this inhibiting action. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis reveals that the iron in the film remains predominantly in the Fe3+ oxidation state even after prolonged electrochemical reduction cycles. These findings suggest that the anesthetics act by inhibiting the interaction between the Fe(acac)3 complex and oxygen, likely through a spin–decoherence mechanism. This work highlights the critical role of anesthetics in modifying the electrochemical behavior of metal-oxygen complexes, with potential implications for sensing, electrocatalysis, and bio-oriented systems.
Spin-Selective Anisotropic Magnetoresistance Driven by Chirality in DNA Tapan Kumar Das, Naupada Preeyanka, Suryakant Mishra, Yutao Sang, Claudio Fontanesi Advanced Functional Materials, 2025 The magnetoresistance (MR) measurements of a ferromagnetic (FM) surface functionalized with 30 base‐pairs DNA molecules (30bp‐dsDNA) is measured both as a function of the angle between the surface normal and magnetization direction and as a function of temperature. In particular, the angular dependence MR follows a periodic pattern passing through zero for the in‐plane magnetization of the ferromagnetic surface, i.e., 90° to the minimum/maximum value of MR for the out‐of‐plane magnetization, i.e., 0°/180°. This is a clear‐cut demonstration of the spatial dependence (anisotropy) of the chiral‐induced spin (CISS) selectivity effect. Remarkably, the anisotropic nature of magnetoresistance in chiral molecular systems demonstrates their significant potential application in the field of organic spintronics, paving the way for innovative developments in spin‐based devices.
Protein Conformation Governs Spin-Selective Electron Transmission Naupada Preeyanka, Tapan Kumar Das, Ron Naaman Journal of Physical Chemistry Letters, 2025 The chiral induced spin selectivity (CISS) effect results in spin-dependent electron transmission through chiral systems. In biological systems such as proteins, chirality appears in both primary and secondary structures, namely, in the existence of asymmetric carbon atoms and in the chiral configuration of oligopeptide subunits. An important question is what contribution each type of chirality makes to this effect. Here we present the impact of denaturation on spin polarization using d-glucose oxidase (GOx) as a model system. Employing Hall-effect and magnetoresistance (MR) measurements, we compared the spin selective behavior of GOx in its native and thermally denatured states. Our results show that the native protein, characterized by a well-defined helical structure and intact flavin adenine dinucleotide (FAD) cofactor, exhibits strong spin polarization. Upon denaturation at elevated temperatures (65 and 95 °C), a marked reduction in both Hall voltage slope and MR values indicates a significant loss in spin polarization capability. This behavior is attributed to the disruption of the protein's secondary structure, which is essential for maintaining chiral potential landscapes for spin selectivity. These findings highlight the importance of secondary structure in maintaining a high spin polarization in proteins. We also demonstrate that the spin-related structural properties of the protein are retained, even when the protein is imbedded in a solid-state device.
Insights into the Mechanism of Chiral-Induced Spin Selectivity: The Effect of Magnetic Field Direction and Temperature Tapan Kumar Das, Ron Naaman, Jonas Fransson Advanced Materials, 2024 Chiral oligopeptide monolayers are adsorbed on a ferromagnetic surface and their magnetoresistance is measured as a function of the angle between the magnetization of the ferromagnet and the surface normal. These measurements are conducted as a function of temperature for both enantiomers. The angle dependence is found to follow a changing trend with a period of 360°. Quantum simulations reveal that the angular distribution can be obtained only if the monolayer has significant effective spin orbit coupling (SOC), that includes contribution from the vibrations. The model shows that SOC only in the leads cannot reproduce the observed angular dependence. The simulation can reproduce the experiments if it included electron–phonon interactions and dissipation.
Spin polarized current in chiral organic radical monolayers Niccolò Giaconi, Michela Lupi, Tapan Kumar Das, Anil Kumar, Lorenzo Poggini, et al. Journal of Materials Chemistry C, 2024 An enantiopure organic radical monolayer on gold exhibits efficient spin selectivity properties in electron transport. This result makes thia[4]azahelicenes promising candidates for the development of chiral spintronic molecular-based devices.
The Importance of Spin-Polarized Charge Reorganization in the Catalytic Activity of D-Glucose Oxidase Naupada Preeyanka, Qirong Zhu, Tapan Kumar Das, Ron Naaman Chemphyschem, 2024 The front cover artwork is provided by Prof. Ron Naaman's group at the Weizmann Institute of Science. The image shows that direct electron transfer through GOx is governed by electron spins, which result from the chiral‐induced spin selectivity (CISS) effect. Read the full text of the Research Article at 10.1002/cphc.202400033.
The Importance of Spin-Polarized Charge Reorganization in the Catalytic Activity of D-Glucose Oxidase Naupada Preeyanka, Qirong Zhu, TapanKumar Das, Ron Naaman Chemphyschem A European Journal of Chemical Physics and Physical Chemistry, 2024 The reaction of D‐glucose oxidase (GOx) with D‐ and L‐glucose was investigated using confocal fluorescence microscopy and Hall voltage measurements, after the enzyme was adsorbed as a monolayer. By adsorbing the enzyme on a ferromagnetic substrate, we verified that the reaction is spin dependent. This conclusion was supported by monitoring the reaction when the enzyme is adsorbed on a Hall device that does not contain any magnetic elements. The spin dependence is consistent with the chiral‐induced spin selectivity (CISS) effect; it can be explained by the improved fidelity of the electron transfer process through the chiral enzyme due to the coupling of the linear momentum of the electrons and their spin. Since the reaction studied often serve as a model system for enzymatic activity, the results may suggest the general importance of the spin‐dependent electron transfer in bio‐chemical processes.
Halide Engineering in Mixed Halide Perovskite-Inspired Cu2AgBiI6 for Solar Cells with Enhanced Performance Vipinraj Sugathan, Maning Liu, Adriana Pecoraro, T. Kumar Das, Tero-Petri Ruoko, et al. ACS Applied Materials and Interfaces, 2024 Cu2AgBiI6 (CABI) is a promising perovskite-inspired absorber for solar cells due to its direct band gap and high absorption coefficient. However, the nonradiative recombination caused by the high extrinsic trap density limits the performance of CABI-based solar cells. In this work, we employ halide engineering by doping bromide anions (Br–) in CABI thin films, in turn significantly improving the power conversion efficiency (PCE). By introducing Br– in the synthetic route of CABI thin films, we identify the optimum composition as CABI-10Br (with 10% Br at the halide site). The tailored composition appears to reduce the deep trap density as shown by time-resolved photoluminescence and transient absorption spectroscopy characterizations. This leads to a dramatic increase in the lifetime of charge carriers, which therefore improves both the external quantum efficiency and the integrated short-circuit current. The photovoltaic performance shows a significant boost since the PCE under standard 1 sun illumination increases from 1.32 to 1.69% (∼30% relative enhancement). Systematic theoretical and experimental characterizations were employed to investigate the effect of Br– incorporation on the optoelectronic properties of CABI. Our results highlight the importance of mitigating trap states in lead-free perovskite-inspired materials and that Br– incorporation at the halide site is an effective strategy for improving the device performance.
Chirality Versus Symmetry: Electron's Spin Selectivity in Nonpolar Chiral Lead–Bromide Perovskites Alexandre Abhervé, Nicolas Mercier, Anil Kumar, Tapan Kumar Das, Jacky Even, et al. Advanced Materials, 2023 In the last decade, chirality‐induced spin selectivity (CISS), the spin‐selective electron transport through chiral molecules, has been described in a large range of materials, from insulators to superconductors. Because more experimental studies are desired for the theoretical understanding of the CISS effect, chiral metal‐halide semiconductors may contribute to the field thanks to their chiroptical and spintronic properties. In this regard, this work uses new chiral organic cations S‐HP1A and R‐HP1A (HP1A = 2‐hydroxy‐propyl‐1‐ammonium) to prepare 2D chiral halide perovskites (HPs) which crystallize in the enantiomorphic space groups P43212 and P41212, respectively. The fourfold symmetry induces antiferroelectricity along the stacking axis which, combined to incomplete Rashba‐like splitting in each individual 2D polar layer, results in rare spin textures in the band structure. As revealed by magnetic conductive‐probe atomic force microscopy (AFM) measurements, these materials show CISS effect with partial spin polarization (SP; ±40–45%). This incomplete effect is efficient enough to drive a chiro‐spintronic device as demonstrated by the fabrication of spin valve devices with magnetoresistance (MR) responses up to 250 K. Therefore, these stable lead–bromide HP materials not only represent interesting candidates for spintronic applications but also reveal the importance of polar symmetry‐breaking topology for spin selectivity.
Chirality induced long-range spin-selective transport in helical 3D metal–organic frameworks PS Bisht, R Garg, TK Das, N Bhatt, SC Sahoo, AK Mondal Chemical Science , 2026 2026
Spin‐Selective Anisotropic Magnetoresistance Driven by Chirality in DNA TK Das, N Preeyanka, S Mishra, Y Sang, C Fontanesi Advanced Functional Materials 35 (36), 2425377 , 2025 2025 Citations: 6
Long‐Range Spin Transport in Chiral Gold T Kumar Das, O Marelly, S Yochelis, Y Paltiel, R Naaman, J Fransson Advanced Materials 37 (34), 2506523 , 2025 2025 Citations: 7
Protein Conformation Governs Spin-Selective Electron Transmission N Preeyanka, TK Das, R Naaman The Journal of Physical Chemistry Letters 16 (25), 6442-6446 , 2025 2025 Citations: 3
Topological Anomalous Hall Effect and Long-Range Spin Transport in Chiral Gold R Naaman, T Das, O Marelly, S Yochelis, Y Paltiel, J Fransson 2025
Insights into the Mechanism of Chiral‐Induced Spin Selectivity: The Effect of Magnetic Field Direction and Temperature TK Das, R Naaman, J Fransson Advanced Materials 36 (29), 2313708 , 2024 2024 Citations: 32
Front Cover: The Importance of Spin‐Polarized Charge Reorganization in the Catalytic Activity of D‐Glucose Oxidase (ChemPhysChem 10/2024) N Preeyanka, Q Zhu, TK Das, R Naaman ChemPhysChem 25 (10), e202400461 , 2024 2024
The Importance of Spin‐Polarized Charge Reorganization in the Catalytic Activity of D‐Glucose Oxidase N Preeyanka, Q Zhu, TK Das, R Naaman ChemPhysChem 25 (10), e202400033 , 2024 2024 Citations: 10
Halide Engineering in Mixed Halide Perovskite-Inspired Cu 2 AgBiI 6 for Solar Cells with Enhanced Performance V Sugathan, M Liu, A Pecoraro, TK Das, TP Ruoko, GK Grandhi, D Manna, ... ACS applied materials & interfaces 16 (15), 19026-19038 , 2024 2024 Citations: 14
Spin polarized current in chiral organic radical monolayers N Giaconi, M Lupi, TK Das, A Kumar, L Poggini, C Viglianisi, L Sorace, ... Journal of Materials Chemistry C 12 (27), 10029-10035 , 2024 2024 Citations: 18
Chirality versus symmetry: electron's spin selectivity in nonpolar chiral lead–bromide perovskites A Abhervé, N Mercier, A Kumar, TK Das, J Even, C Katan, M Kepenekian Advanced Materials 35 (51), 2305784 , 2023 2023 Citations: 51
Highly conductive topologically chiral molecular knots as efficient spin filters DY Zhang, Y Sang, TK Das, Z Guan, N Zhong, CG Duan, W Wang, ... Journal of the American Chemical Society 145 (49), 26791-26798 , 2023 2023 Citations: 74
Bacterial extracellular electron transfer components are spin selective CM Niman, N Sukenik, T Dang, J Nwachukwu, MA Thirumurthy, AK Jones, ... The Journal of chemical physics 159 (14) , 2023 2023 Citations: 19
Efficient spin-selective electron transport at low voltages of thia-bridged triarylamine hetero [4] helicenes chemisorbed monolayer N Giaconi, L Poggini, M Lupi, M Briganti, A Kumar, TK Das, AL Sorrentino, ... ACS nano 17 (15), 15189-15198 , 2023 2023 Citations: 40
Spin-induced electron transmission through metal–organic chiral crystals TK Das, AK Mondal, OS Tiwari, P Makam, G Leitus, E Gazit, F Claudio, ... Physical Chemistry Chemical Physics 25 (33), 22124-22129 , 2023 2023 Citations: 19
The role of electrons’ spin in DNA oxidative damage recognition Q Zhu, Y Kapon, AM Fleming, S Mishra, K Santra, F Tassinari, SR Cohen, ... Cell reports physical science 3 (12) , 2022 2022 Citations: 12
Spin-induced asymmetry reaction—The formation of asymmetric carbon by electropolymerization DK Bhowmick, TK Das, K Santra, AK Mondal, F Tassinari, R Schwarz, ... Science advances 8 (31), eabq2727 , 2022 2022 Citations: 43
Mutual monomer orientation to bias the supramolecular polymerization of [6] helicenes and the resulting circularly polarized light and spin filtering properties R Rodríguez, C Naranjo, A Kumar, P Matozzo, TK Das, Q Zhu, ... Journal of the American Chemical Society 144 (17), 7709-7719 , 2022 2022 Citations: 138
Temperature-Dependent Chiral-Induced Spin Selectivity Effect: Experiments and Theory TK Das, F Tassinari, R Naaman, J Fransson The Journal of Physical Chemistry C 126 (6), 3257-3264 , 2022 2022 Citations: 154
Metal organic spin transistor N Goren, TK Das, N Brown, S Gilead, S Yochelis, E Gazit, R Naaman, ... Nano letters 21 (20), 8657-8663 , 2021 2021 Citations: 41
MOST CITED SCHOLAR PUBLICATIONS
Highly efficient and tunable filtering of Electrons' spin by supramolecular chirality of nanofiber‐based materials C Kulkarni, AK Mondal, TK Das, G Grinbom, F Tassinari, MFJ Mabesoone, ... Advanced Materials 32 (7), 1904965 , 2020 2020 Citations: 278
Length-dependent electron spin polarization in oligopeptides and DNA S Mishra, AK Mondal, S Pal, TK Das, EZB Smolinsky, G Siligardi, ... The Journal of Physical Chemistry C 124 (19), 10776-10782 , 2020 2020 Citations: 186
Spin filtering in supramolecular polymers assembled from achiral monomers mediated by chiral solvents AK Mondal, MD Preuss, ML Sleczkowski, TK Das, G Vantomme, ... Journal of the American Chemical Society 143 (18), 7189-7195 , 2021 2021 Citations: 166
Tunable and Stable White Light Emission in Bi 3+ -Alloyed Cs 2 AgInCl 6 Double Perovskite Nanocrystals D Manna, TK Das, A Yella Chemistry of Materials 31 (24), 10063-10070 , 2019 2019 Citations: 163
Temperature-Dependent Chiral-Induced Spin Selectivity Effect: Experiments and Theory TK Das, F Tassinari, R Naaman, J Fransson The Journal of Physical Chemistry C 126 (6), 3257-3264 , 2022 2022 Citations: 154
Mutual monomer orientation to bias the supramolecular polymerization of [6] helicenes and the resulting circularly polarized light and spin filtering properties R Rodríguez, C Naranjo, A Kumar, P Matozzo, TK Das, Q Zhu, ... Journal of the American Chemical Society 144 (17), 7709-7719 , 2022 2022 Citations: 138
Lattice Dynamics and Electron–Phonon Coupling in Lead-Free Cs 2 AgIn 1– x Bi x Cl 6 Double Perovskite Nanocrystals D Manna, J Kangsabanik, TK Das, D Das, A Alam, A Yella The Journal of Physical Chemistry Letters 11 (6), 2113-2120 , 2020 2020 Citations: 108
Influence of surface disorder, oxygen defects and bandgap in TiO2 nanostructures on the photovoltaic properties of dye sensitized solar cells TK Das, P Ilaiyaraja, PSV Mocherla, GM Bhalerao, C Sudakar Solar Energy Materials and Solar Cells 144, 194-209 , 2016 2016 Citations: 99
Highly conductive topologically chiral molecular knots as efficient spin filters DY Zhang, Y Sang, TK Das, Z Guan, N Zhong, CG Duan, W Wang, ... Journal of the American Chemical Society 145 (49), 26791-26798 , 2023 2023 Citations: 74
Template assisted nanoporous TiO2 nanoparticles: The effect of oxygen vacancy defects on photovoltaic performance of DSSC and QDSSC TK Das, P Ilaiyaraja, C Sudakar Solar Energy 159, 920-929 , 2018 2018 Citations: 65
Reversible dimensionality tuning of hybrid perovskites with humidity: visualization and application to stable solar cells SK Sharma, C Phadnis, TK Das, A Kumar, B Kavaipatti, A Chowdhury, ... Chemistry of materials 31 (9), 3111-3117 , 2019 2019 Citations: 60
Chirality versus symmetry: electron's spin selectivity in nonpolar chiral lead–bromide perovskites A Abhervé, N Mercier, A Kumar, TK Das, J Even, C Katan, M Kepenekian Advanced Materials 35 (51), 2305784 , 2023 2023 Citations: 51
CuInS2 quantum dot sensitized solar cells with high VOC≈ 0.9 V achieved using microsphere-nanoparticulate TiO2 composite photoanode P Ilaiyaraja, B Rakesh, TK Das, PSV Mocherla, C Sudakar Solar Energy Materials and Solar Cells 178, 208-222 , 2018 2018 Citations: 47
Spin-induced asymmetry reaction—The formation of asymmetric carbon by electropolymerization DK Bhowmick, TK Das, K Santra, AK Mondal, F Tassinari, R Schwarz, ... Science advances 8 (31), eabq2727 , 2022 2022 Citations: 43
Whispering gallery mode enabled efficiency enhancement: defect and size controlled CdSe quantum dot sensitized whisperonic solar cells TK Das, P Ilaiyaraja, C Sudakar Scientific Reports 8 (1), 9709 , 2018 2018 Citations: 42
Whispering Gallery Mode Assisted Enhancement in the Power Conversion Efficiency of DSSC and QDSSC Devices Using TiO 2 Microsphere Photoanodes TK Das, P Ilaiyaraja, C Sudakar ACS Applied Energy Materials 1 (2), 765-774 , 2018 2018 Citations: 42
Metal organic spin transistor N Goren, TK Das, N Brown, S Gilead, S Yochelis, E Gazit, R Naaman, ... Nano letters 21 (20), 8657-8663 , 2021 2021 Citations: 41
Efficient spin-selective electron transport at low voltages of thia-bridged triarylamine hetero [4] helicenes chemisorbed monolayer N Giaconi, L Poggini, M Lupi, M Briganti, A Kumar, TK Das, AL Sorrentino, ... ACS nano 17 (15), 15189-15198 , 2023 2023 Citations: 40
Well-connected microsphere-nanoparticulate TiO2 composites as high performance photoanode for dye sensitized solar cell P Ilaiyaraja, TK Das, PSV Mocherla, C Sudakar Solar Energy Materials and Solar Cells 169, 86-97 , 2017 2017 Citations: 34
Insights into the Mechanism of Chiral‐Induced Spin Selectivity: The Effect of Magnetic Field Direction and Temperature TK Das, R Naaman, J Fransson Advanced Materials 36 (29), 2313708 , 2024 2024 Citations: 32
