@article{20670, abstract = {β-Barrel nanopores are involved in crucial biological processes, from ATP export in mitochondria to bacterial resistance, and represent a promising platform for emerging sequencing technologies. However, in contrast to ion channels, the understanding of the fundamental principles governing ion transport through these nanopores remains largely unexplored. Here we integrate experimental, numerical and theoretical approaches to elucidate ion transport mechanisms in β-barrel nanopores. We identify and characterize two distinct nonlinear phenomena: open-pore rectification and gating. Through extensive mutation analysis of aerolysin nanopores, we demonstrate that open-pore rectification is caused by ionic accumulation driven by the distribution of lumen charges. In addition, we provide converging evidence suggesting that gating is controlled by electric fields dissociating counterions from lumen charges, promoting local structural deformations. Our findings establish a rigorous framework for characterizing and understanding ion transport processes in protein-based nanopores, enabling the design of adaptable nanofluidic biotechnologies. We illustrate this by optimizing an aerolysin mutant for computing applications.}, author = {Mayer, Simon and Mitsioni, Marianna Fanouria and Robin, Paul and Van Den Heuvel, Lukas and Ronceray, Nathan and Marcaida, Maria Jose and Abriata, Luciano A. and Krapp, Lucien F. and Anton, Jana S. and Soussou, Sarah and Jeanneret-Grosjean, Justin and Fulciniti, Alessandro and Möller, Alexia and Vacle, Sarah and Feletti, Lely and Brinkerhoff, Henry and Laszlo, Andrew H. and Gundlach, Jens H. and Emmerich, Theo and Dal Peraro, Matteo and Radenovic, Aleksandra}, issn = {1748-3395}, journal = {Nature Nanotechnology}, pages = {116--124}, publisher = {Springer Nature}, title = {{Lumen charge governs gated ion transport in β-barrel nanopores}}, doi = {10.1038/s41565-025-02052-6}, volume = {21}, year = {2026}, } @article{17480, abstract = {One of the most promising approaches towards large-scale quantum computation uses devices based on many Josephson junctions. Yet, even today, open questions regarding the single junction remain unsolved, such as the detailed understanding of the quantum phase transitions, the coupling of the Josephson junction to the environment or how to improve the coherence of a superconducting qubit. Here we design and build an engineered on-chip reservoir connected to a Josephson junction that acts as an efficient bolometer for detecting the Josephson radiation under non-equilibrium, that is, biased conditions. The bolometer converts the a.c. Josephson current at microwave frequencies up to about 100 GHz into a temperature rise measured by d.c. thermometry. A circuit model based on realistic parameter values captures both the current–voltage characteristics and the measured power quantitatively. The present experiment demonstrates an efficient, wide-band, thermal detection scheme of microwave photons and provides a sensitive detector of Josephson dynamics beyond the standard conductance measurements.}, author = {Karimi, Bayan and Steffensen, Gorm Ole and Higginbotham, Andrew P and Marcus, Charles M. and Levy Yeyati, Alfredo and Pekola, Jukka P.}, issn = {1748-3395}, journal = {Nature Nanotechnology}, pages = {1613--1618}, publisher = {Springer Nature}, title = {{Bolometric detection of Josephson radiation}}, doi = {10.1038/s41565-024-01770-7}, volume = {19}, year = {2024}, } @article{13352, abstract = {Optoelectronic effects differentiating absorption of right and left circularly polarized photons in thin films of chiral materials are typically prohibitively small for their direct photocurrent observation. Chiral metasurfaces increase the electronic sensitivity to circular polarization, but their out-of-plane architecture entails manufacturing and performance trade-offs. Here, we show that nanoporous thin films of chiral nanoparticles enable high sensitivity to circular polarization due to light-induced polarization-dependent ion accumulation at nanoparticle interfaces. Self-assembled multilayers of gold nanoparticles modified with L-phenylalanine generate a photocurrent under right-handed circularly polarized light as high as 2.41 times higher than under left-handed circularly polarized light. The strong plasmonic coupling between the multiple nanoparticles producing planar chiroplasmonic modes facilitates the ejection of electrons, whose entrapment at the membrane–electrolyte interface is promoted by a thick layer of enantiopure phenylalanine. Demonstrated detection of light ellipticity with equal sensitivity at all incident angles mimics phenomenological aspects of polarization vision in marine animals. The simplicity of self-assembly and sensitivity of polarization detection found in optoionic membranes opens the door to a family of miniaturized fluidic devices for chiral photonics.}, author = {Cai, Jiarong and Zhang, Wei and Xu, Liguang and Hao, Changlong and Ma, Wei and Sun, Maozhong and Wu, Xiaoling and Qin, Xian and Colombari, Felippe Mariano and de Moura, André Farias and Xu, Jiahui and Silva, Mariana Cristina and Carneiro-Neto, Evaldo Batista and Gomes, Weverson Rodrigues and Vallée, Renaud A. L. and Pereira, Ernesto Chaves and Liu, Xiaogang and Xu, Chuanlai and Klajn, Rafal and Kotov, Nicholas A. and Kuang, Hua}, issn = {1748-3395}, journal = {Nature Nanotechnology}, keywords = {Electrical and Electronic Engineering, Condensed Matter Physics, General Materials Science, Biomedical Engineering, Atomic and Molecular Physics, and Optics, Bioengineering}, number = {4}, pages = {408--416}, publisher = {Springer Nature}, title = {{Polarization-sensitive optoionic membranes from chiral plasmonic nanoparticles}}, doi = {10.1038/s41565-022-01079-3}, volume = {17}, year = {2022}, } @article{17900, abstract = {To rival the performance of modern integrated circuits, single-molecule devices must be designed to exhibit extremely nonlinear current–voltage (I–V) characteristics1,2,3,4. A common approach is to design molecular backbones where destructive quantum interference (QI) between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) produces a nonlinear energy-dependent tunnelling probability near the electrode Fermi energy (EF)5,6,7,8. However, tuning such systems is not straightforward, as aligning the frontier orbitals to EF is hard to control9. Here, we instead create a molecular system where constructive QI between the HOMO and LUMO is suppressed and destructive QI between the HOMO and strongly coupled occupied orbitals of opposite phase is enhanced. We use a series of fluorene oligomers containing a central benzothiadiazole10 unit to demonstrate that this strategy can be used to create highly nonlinear single-molecule circuits. Notably, we are able to reproducibly modulate the conductance of a 6-nm molecule by a factor of more than 10^4.}, author = {Greenwald, Julia E. and Cameron, Joseph and Findlay, Neil J. and Fu, Tianren and Gunasekaran, Suman and Skabara, Peter J. and Venkataraman, Latha}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {3}, pages = {313--317}, publisher = {Springer Nature}, title = {{Highly nonlinear transport across single-molecule junctions via destructive quantum interference}}, doi = {10.1038/s41565-020-00807-x}, volume = {16}, year = {2021}, } @article{13367, abstract = {Confining molecules can fundamentally change their chemical and physical properties. Confinement effects are considered instrumental at various stages of the origins of life, and life continues to rely on layers of compartmentalization to maintain an out-of-equilibrium state and efficiently synthesize complex biomolecules under mild conditions. As interest in synthetic confined systems grows, we are realizing that the principles governing reactivity under confinement are the same in abiological systems as they are in nature. In this Review, we categorize the ways in which nanoconfinement effects impact chemical reactivity in synthetic systems. Under nanoconfinement, chemical properties can be modulated to increase reaction rates, enhance selectivity and stabilize reactive species. Confinement effects also lead to changes in physical properties. The fluorescence of light emitters, the colours of dyes and electronic communication between electroactive species can all be tuned under confinement. Within each of these categories, we elucidate design principles and strategies that are widely applicable across a range of confined systems, specifically highlighting examples of different nanocompartments that influence reactivity in similar ways.}, author = {Grommet, Angela B. and Feller, Moran and Klajn, Rafal}, issn = {1748-3395}, journal = {Nature Nanotechnology}, keywords = {Electrical and Electronic Engineering, Condensed Matter Physics, General Materials Science, Biomedical Engineering, Atomic and Molecular Physics, and Optics, Bioengineering}, pages = {256--271}, publisher = {Springer Nature}, title = {{Chemical reactivity under nanoconfinement}}, doi = {10.1038/s41565-020-0652-2}, volume = {15}, year = {2020}, } @article{6053, abstract = {Recent technical developments in the fields of quantum electromechanics and optomechanics have spawned nanoscale mechanical transducers with the sensitivity to measure mechanical displacements at the femtometre scale and the ability to convert electromagnetic signals at the single photon level. A key challenge in this field is obtaining strong coupling between motion and electromagnetic fields without adding additional decoherence. Here we present an electromechanical transducer that integrates a high-frequency (0.42 GHz) hypersonic phononic crystal with a superconducting microwave circuit. The use of a phononic bandgap crystal enables quantum-level transduction of hypersonic mechanical motion and concurrently eliminates decoherence caused by acoustic radiation. Devices with hypersonic mechanical frequencies provide a natural pathway for integration with Josephson junction quantum circuits, a leading quantum computing technology, and nanophotonic systems capable of optical networking and distributing quantum information.}, author = {Kalaee, Mahmoud and Mirhosseini, Mohammad and Dieterle, Paul B. and Peruzzo, Matilda and Fink, Johannes M and Painter, Oskar}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {4}, pages = {334–339}, publisher = {Springer Nature}, title = {{Quantum electromechanics of a hypersonic crystal}}, doi = {10.1038/s41565-019-0377-2}, volume = {14}, year = {2019}, } @article{17937, abstract = {Fabricating nanoscopic devices capable of manipulating and processing single units of charge is an essential step towards creating functional devices where quantum effects dominate transport characteristics. The archetypal single-electron transistor comprises a small conducting or semiconducting island separated from two metallic reservoirs by insulating barriers1,2,3,4,5. By enabling the transfer of a well-defined number of charge carriers between the island and the reservoirs, such a device may enable discrete single-electron operations6,7,8,9. Here, we describe a single-molecule junction comprising a redox-active, atomically precise cobalt chalcogenide cluster wired between two nanoscopic electrodes10,11. We observe current blockade at room temperature in thousands of single-cluster junctions. Below a threshold voltage, charge transfer across the junction is suppressed. The device is turned on when the temporary occupation of the core states by a transiting carrier is energetically enabled, resulting in a sequential tunnelling process and an increase in current by a factor of ∼600. We perform in situ and ex situ cyclic voltammetry as well as density functional theory calculations to unveil a two-step process mediated by an orbital localized on the core of the cluster in which charge carriers reside before tunnelling to the collector reservoir. As the bias window of the junction is opened wide enough to include one of the cluster frontier orbitals, the current blockade is lifted and charge carriers can tunnel sequentially across the junction.}, author = {Lovat, Giacomo and Choi, Bonnie and Paley, Daniel W. and Steigerwald, Michael L. and Venkataraman, Latha and Roy, Xavier}, issn = {1748-3395}, journal = {Nature Nanotechnology}, pages = {1050--1054}, publisher = {Springer Nature}, title = {{Room-temperature current blockade in atomically defined single-cluster junctions}}, doi = {10.1038/nnano.2017.156}, volume = {12}, year = {2017}, } @article{13392, abstract = {The chemical behaviour of molecules can be significantly modified by confinement to volumes comparable to the dimensions of the molecules. Although such confined spaces can be found in various nanostructured materials, such as zeolites, nanoporous organic frameworks and colloidal nanocrystal assemblies, the slow diffusion of molecules in and out of these materials has greatly hampered studying the effect of confinement on their physicochemical properties. Here, we show that this diffusion limitation can be overcome by reversibly creating and destroying confined environments by means of ultraviolet and visible light irradiation. We use colloidal nanocrystals functionalized with light-responsive ligands that readily self-assemble and trap various molecules from the surrounding bulk solution. Once trapped, these molecules can undergo chemical reactions with increased rates and with stereoselectivities significantly different from those in bulk solution. Illumination with visible light disassembles these nanoflasks, releasing the product in solution and thereby establishes a catalytic cycle. These dynamic nanoflasks can be useful for studying chemical reactivities in confined environments and for synthesizing molecules that are otherwise hard to achieve in bulk solution.}, author = {Zhao, Hui and Sen, Soumyo and Udayabhaskararao, T. and Sawczyk, Michał and Kučanda, Kristina and Manna, Debasish and Kundu, Pintu K. and Lee, Ji-Woong and Král, Petr and Klajn, Rafal}, issn = {1748-3395}, journal = {Nature Nanotechnology}, keywords = {Electrical and Electronic Engineering, Condensed Matter Physics, General Materials Science, Biomedical Engineering, Atomic and Molecular Physics, and Optics, Bioengineering}, pages = {82--88}, publisher = {Springer Nature}, title = {{Reversible trapping and reaction acceleration within dynamically self-assembling nanoflasks}}, doi = {10.1038/nnano.2015.256}, volume = {11}, year = {2015}, } @article{17972, abstract = {Molecular electronics aims to miniaturize electronic devices by using subnanometre-scale active components1,2,3. A single-molecule diode, a circuit element that directs current flow4, was first proposed more than 40 years ago5 and consisted of an asymmetric molecule comprising a donor–bridge–acceptor architecture to mimic a semiconductor p–n junction. Several single-molecule diodes have since been realized in junctions featuring asymmetric molecular backbones6,7,8, molecule–electrode linkers9 or electrode materials10. Despite these advances, molecular diodes have had limited potential for applications due to their low conductance, low rectification ratios, extreme sensitivity to the junction structure and high operating voltages7,8,9,11,12. Here, we demonstrate a powerful approach to induce current rectification in symmetric single-molecule junctions using two electrodes of the same metal, but breaking symmetry by exposing considerably different electrode areas to an ionic solution. This allows us to control the junction's electrostatic environment in an asymmetric fashion by simply changing the bias polarity. With this method, we reliably and reproducibly achieve rectification ratios in excess of 200 at voltages as low as 370 mV using a symmetric oligomer of thiophene-1,1-dioxide13,14. By taking advantage of the changes in the junction environment induced by the presence of an ionic solution, this method provides a general route for tuning nonlinear nanoscale device phenomena, which could potentially be applied in systems beyond single-molecule junctions.}, author = {Capozzi, Brian and Xia, Jianlong and Adak, Olgun and Dell, Emma J. and Liu, Zhen-Fei and Taylor, Jeffrey C. and Neaton, Jeffrey B. and Campos, Luis M. and Venkataraman, Latha}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {6}, pages = {522--527}, publisher = {Springer Nature}, title = {{Single-molecule diodes with high rectification ratios through environmental control}}, doi = {10.1038/nnano.2015.97}, volume = {10}, year = {2015}, } @article{17999, abstract = {The idea of using individual molecules as active electronic components provided the impetus to develop a variety of experimental platforms to probe their electronic transport properties. Among these, single-molecule junctions in a metal–molecule–metal motif have contributed significantly to our fundamental understanding of the principles required to realize molecular-scale electronic components from resistive wires to reversible switches. The success of these techniques and the growing interest of other disciplines in single-molecule-level characterization are prompting new approaches to investigate metal–molecule–metal junctions with multiple probes. Going beyond electronic transport characterization, these new studies are highlighting both the fundamental and applied aspects of mechanical, optical and thermoelectric properties at the atomic and molecular scales. Furthermore, experimental demonstrations of quantum interference and manipulation of electronic and nuclear spins in single-molecule circuits are heralding new device concepts with no classical analogues. In this Review, we present the emerging methods being used to interrogate multiple properties in single molecule-based devices, detail how these measurements have advanced our understanding of the structure–function relationships in molecular junctions, and discuss the potential for future research and applications.}, author = {Aradhya, Sriharsha V. and Venkataraman, Latha}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {6}, pages = {399--410}, publisher = {Springer Nature}, title = {{Single-molecule junctions beyond electronic transport}}, doi = {10.1038/nnano.2013.91}, volume = {8}, year = {2013}, } @article{18007, abstract = {According to Kirchhoff's circuit laws, the net conductance of two parallel components in an electronic circuit is the sum of the individual conductances. However, when the circuit dimensions are comparable to the electronic phase coherence length, quantum interference effects play a critical role1, as exemplified by the Aharonov–Bohm effect in metal rings2,3. At the molecular scale, interference effects dramatically reduce the electron transfer rate through a meta-connected benzene ring when compared with a para-connected benzene ring4,5. For longer conjugated and cross-conjugated molecules, destructive interference effects have been observed in the tunnelling conductance through molecular junctions6,7,8,9,10. Here, we investigate the conductance superposition law for parallel components in single-molecule circuits, particularly the role of interference. We synthesize a series of molecular systems that contain either one backbone or two backbones in parallel, bonded together cofacially by a common linker on each end. Single-molecule conductance measurements and transport calculations based on density functional theory show that the conductance of a double-backbone molecular junction can be more than twice that of a single-backbone junction, providing clear evidence for constructive interference.}, author = {Vazquez, H. and Skouta, R. and Schneebeli, S. and Kamenetska, M. and Breslow, R. and Venkataraman, Latha and Hybertsen, M.S.}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {10}, pages = {663--667}, publisher = {Springer Nature}, title = {{Probing the conductance superposition law in single-molecule circuits with parallel paths}}, doi = {10.1038/nnano.2012.147}, volume = {7}, year = {2012}, } @article{18021, abstract = {Charge transport across metal–molecule interfaces has an important role in organic electronics1. Typically, chemical link groups such as thiols2 or amines3 are used to bind organic molecules to metal electrodes in single-molecule circuits, with these groups controlling both the physical structure and the electronic coupling at the interface. Direct metal–carbon coupling has been shown through C60, benzene and π-stacked benzene4,5,6,7, but ideally the carbon backbone of the molecule should be covalently bonded to the electrode without intervening link groups. Here, we demonstrate a method to create junctions with such contacts. Trimethyl tin (SnMe3)-terminated polymethylene chains are used to form single-molecule junctions with a break-junction technique2,3. Gold atoms at the electrode displace the SnMe3 linkers, leading to the formation of direct Au–C bonded single-molecule junctions with a conductance that is ∼100 times larger than analogous alkanes with most other terminations. The conductance of these Au–C bonded alkanes decreases exponentially with molecular length, with a decay constant of 0.97 per methylene, consistent with a non-resonant transport mechanism. Control experiments and ab initio calculations show that high conductances are achieved because a covalent Au–C sigma (σ) bond is formed. This offers a new method for making reproducible and highly conducting metal–organic contacts.}, author = {Cheng, Z.-L. and Skouta, R. and Vazquez, H. and Widawsky, J. R. and Schneebeli, S. and Chen, W. and Hybertsen, M. S. and Breslow, R. and Venkataraman, Latha}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {6}, pages = {353--357}, publisher = {Springer Nature}, title = {{In situ formation of highly conducting covalent Au–C contacts for single-molecule junctions}}, doi = {10.1038/nnano.2011.66}, volume = {6}, year = {2011}, } @article{18031, abstract = {Molecular-scale components are expected to be central to the realization of nanoscale electronic devices1,2,3. Although molecular-scale switching has been reported in atomic quantum point contacts4,5,6, single-molecule junctions provide the additional flexibility of tuning the on/off conductance states through molecular design. To date, switching in single-molecule junctions has been attributed to changes in the conformation or charge state of the molecule7,8,9,10,11,12. Here, we demonstrate reversible binary switching in a single-molecule junction by mechanical control of the metal–molecule contact geometry. We show that 4,4'-bipyridine–gold single-molecule junctions can be reversibly switched between two conductance states through repeated junction elongation and compression. Using first-principles calculations, we attribute the different measured conductance states to distinct contact geometries at the flexible but stable nitrogen–gold bond: conductance is low when the N–Au bond is perpendicular to the conducting π-system, and high otherwise. This switching mechanism, inherent to the pyridine–gold link, could form the basis of a new class of mechanically activated single-molecule switches.}, author = {Quek, Su Ying and Kamenetska, Maria and Steigerwald, Michael L. and Choi, Hyoung Joon and Louie, Steven G. and Hybertsen, Mark S. and Neaton, J. B. and Venkataraman, Latha}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {4}, pages = {230--234}, publisher = {Springer Nature}, title = {{Mechanically controlled binary conductance switching of a single-molecule junction}}, doi = {10.1038/nnano.2009.10}, volume = {4}, year = {2009}, } @article{18034, abstract = {The ability to perform optical measurements on a single molecule placed between two electrodes while also measuring the current flowing through it could herald a new generation of experiments on molecular junctions.}, author = {Venkataraman, Latha}, issn = {1748-3395}, journal = {Nature Nanotechnology}, number = {4}, pages = {187--188}, publisher = {Springer Nature}, title = {{Seeing is believing}}, doi = {10.1038/nnano.2008.81}, volume = {3}, year = {2008}, }