Our research interests in the group revolve around charged interfaces and charge transport at the nanoscale and in electrochemical environments. We employ various in situ Scanning Probe Microscopy techniques (e.g., EC-STM and EC-AFM), electrochemical methods including impedance spectroscopy, and custom-built, high-performance amplifiers for nanopore sensing. We actively collaborate with other chemists, physicists, materials scientists, electronics engineers and machine-learning experts.
Charge Transport in Single Molecules
While charge transport in linear molecules is fairly well understood, the situation is quite different for branched or ring-shaped molecules. Depending on the charge transport mechanism, quantum interference (QI) or new types of hopping phenomena may occur, which in the case of QI can enhance the thermoelectric performance of a molecule. Hence, in this activity we study 'new' molecules, in an effort to understand their complex interfacial and charge transport behaviour.
For more information, please see the following research papers:
- LE Wilson, C Hassenrück, RF Winter, AJP White, T Albrecht, NJ Long, "Ferrocene- and Biferrocene-Containing Macrocycles towards Single-Molecule Electronics", Angew. Chem. 2017, 56, 6838-6842.
- MS Inkpen, S Scheerer, M Linseis, AJP White, RF Winter, T Albrecht, NJ Long, "Oligomeric ferrocene rings", Nat. Chem. 2016, 8, 825-830.
Quantum Tunnelling for Sensing and Sequencing
Is it possible to use the quantum-mechanical tunnelling effect for sequencing of biopolymer's, such as DNA, RNA and proteins? This is an intriguing possibility, but also an enormous challenge. In recent years, we have made significant progress towards this goal, by showing that tunnelling detection of single DNA molecules is indeed compatible with a high-throughput analysis platform (nanopores). We are now pushing the limits on single-base detection in EC-STM, with a combination of surface engineering and state-of-the-art machine learning techniques, including Deep Learning.
For more information, please read the following research papers:
- AP Ivanov, E Instuli, CM McGilvery, G Baldwin, DW McComb, T Albrecht, JB Edel, "DNA Tunnelling Detector Embedded in a Nanopore", Nano Letters 2011, 11, 279-285.
- T Albrecht, "Electrochemical tunnelling sensors and their potential applications", Nat. Comm. 2012, 3, 829.
Single-molecule sensing with nanopore and nanopipettes
This is an exciting field of research, which spans from fundamental biophysical studies on biopolymers to biosensing and diagnostics. Based on rather unique instrumental capabilities, we are in a position to not only detect and control translocation of single biomolecules, but also to characterise them at a sub-molecular level. This opens up new avenues towards all-electronic biosensing and new types of DNA assays.
For more information, please read the following research papers:
- RL Fraccari, P Ciccarella, A Bahrami, M Carminati, G Ferrari, T Albrecht, "High-speed detection of DNA translocation in nanopipettes", Nanoscale 2016, 8, 7604-7611.
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RL Fraccari, M Carminati, G Piantanida, T Leontidou, G Ferrari, T Albrecht, "High-bandwidth detection of short DNA in nanopipettes", Faraday Disc. 2016, 193, 459-470.
Machine Learning in Single-Molecule Science
The exploration and application of Machine Learning tools has become an underpinning theme in various aspects of our work, including dimensionality reduction techniques (PCA, MPVC, t-SNE), Autoencoders for unsupervised classification, Support Vector Machines, and Deep Learning methods such as Convolutional Neural Networks.
For more information, please read the following research papers:
- M Lemmer, MS Inkpen, K Kornysheva, NJ Long, T Albrecht, "Unsupervised vector-based classification of single-molecule charge transport data", Nat. Comm. 2016, 7, 12922.
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T Albrecht, G Slabaugh, E Alonso, S M Masudur R Al-Arif, "Deep learning for single-molecule science", Nanotechnology 2017, DOI: 10.1088/1361-6528/aa8334.