• DNA chemistry
• Chemical Biology
• Medicinal chemistry
• Cancer
• Gene expression

The general research interests in the Stulz group are concerned with supramolecular chemistry, bio-nanotechnology, medicinal chemistry, nanoparticles and microfluidics.

We are mainly exploring the use of modified DNA in a number of applications, ranging from electronics over gene expression to novel platform technologies in health care. The research is highly interdisciplinary, and reaches into materials science, nanotechnology, analytical science, and into biological / medicinal sciences. We have reviewed the progress in the use of modified DNA in Chem. Soc. Rev. 2011, in Chem. Eur. J. 2012 and in Acc Chem Res 2017. We have also contributed to books and book chapters: Bio-inspired Functional DNA Architectures (Springer 2021); DNA in Supramolecular Chemistry and Nanotechnology (Wiley 2014).

In addition, we are investigating in the synthesis of silver nanoprisms for energy applications. We have shown that Ag-NPs can successfully be embedded in a polymer matrix and coated onto glass windows, thus forming an IR-light blocking layer to create more energy efficient windows. One of our main themes is now to develop 3D-printed flow-through reactors for continuous flow synthesis of Ag-NPs, which can also be applied to other nanoparticles (e.g. liposomes). The costs of a device is now as low as £5.

DNA in the chemistry - biology - medicine interface

We use modified nucleotides and oligonucleotides (ONs) in biology and medicine to target a number of issues. In particular gene expression and diagnostics profit highly from the use of synthetic DNA. We are pursuing several systems to address regulation of gene expression, targeted cell killing and sensing of ODN markers; the majority of the applications are targeted at cancer therapy.

To advance the field of ONs in medicinal applications, we are leading the H2020-MSCA-ETN OLIGOMED, which comprises academic groups, SMEs, pharma and hospitals across Europe and targets cancer, Huntington's Disease and cardiovascular diseases.

DNA nanopores

We have developed DNA based membrane nanopores, which form stable inclusion complexes in lipid bilayers. Together with the groups of Stefan Howorka (UCL) and Ulrich Keyser (Cambridge) we have studied several types of pore forming DNA systems ( HOT paper in Angew. Chem. 2013, Nano Lett. 2013). We found that two porphyrins are sufficient to form very stable insertions for a six-helical DNA bundle. The simple design allows for the creation of a pore of approximately 5 nm width and 14 nm height, with an inner pore diameter of 2 nm. Current recordings of the ionic flow across the lipid bilayer confirms the formation of the nanopore.

In addition, we could show that a 6-porphyrin containing DNA duplex inserts into the lipid bilayer and induces a flow of ions along the phosphate backbone. This leads to the formation of the smallest possible DNA nanopore, i.e. a single DNA duplex (Nano Lett. 2016). It also reveals that it will not be possible to completely suppress ion flows in larger DNA nanopores, e.g. by blocking the channel.

We are now investigating the nanopores in targeted cell killing.

DNA sensors

Porphyrins have shown to be perfectly well suited to create electrochemical sensors for DNA. Together with the group of Jerzy Radecki and Hanna Radecka in Olsztyn, Poland, we are using cobalt metallated porphyrins that show to be ultrasensitive towards hybridisation with the complementary sequence (Chem. Commun. 2014). The sensor is very selective, able to discriminate single nucleotide polymorphism, and extremely sensitive: with the use of gold nanoparticles on the surface of the electrode, our sensors have a detection limit in the attomolar range and can sense as few as 23 DNA molecules (Chem. Commun. 2018; Bioelectrochemistry 2021).

Silver Nanoparticles in energy

In times of man-made global warming – and with it climate change – it is crucial to tackle general energy problems. Our efforts to contribute to this field is in the formation of silver nanoprisms and nanorods, which efficiently absorb infrared light. These can be coated in a silica shell and covalently embedded in a PMMA matrix for coating of windows (J. Mater. Chem. C 2016). In this way we have shown that the Ag-NPs are able to block the IR light efficiently with sub-mm film thickness. This is a well-going collaboration with the group of Xunli Zhang in Engineering.

Flow through reactors

Our focus is on designing cheap flow-through reactors for the synthesis of nanoparticles (RSC Adv. 2014; J. Mater. Chem. C 2013), in particular silver nanospheres and nanoprisms, but they are also applicable to the fabrication of liposomes. We design the channels of the flow reactors according to best mixing of the different solutions and create a mould using 3D printing (New Biotechnology 2018). The reactor is then made using PDMS and either covering with a glass slide or adhesive tape. This allows to make a flow reactor in less than a day, at costs of less than £5.