The aim of the research project is to visualize viral contamination on surfaces using allosteric aptamers.

The allosteric aptamers recognize viral pathogens and initiate a hybridization chain reaction in which oligonucleotides with a hairpin structure, which are partially functionalized with gold nanoparticles, autonomously assemble into highly branched nucleic acid structures (plasmonically active dendrones).

The accumulation of gold nanoparticles in the dendrons is accompanied by a visually perceptible color change.

In order to develop allosteric aptamers against a target protein on the surface of a viral pathogen, a special process is required, which is referred to as SEALEX (Systematic Evolution of Allosteric Ligands by EXponential Enrichment), based on the methods described for aptamer selection.

The project results will provide cleaning service providers and textile service providers with evidence of viral contamination, enabling them for the first time to monitor the virucidal effect of the cleaning/disinfection measures they carry out on site as part of in-house self-monitoring.

This allows errors to be identified more quickly and hygiene safety to be optimized. In principle, it is also conceivable that the detection method developed could be used for diagnostic purposes in medicine.