Fabrication of a colorimetric biosensing platform for the detection of protein–DNA interaction

Protein–DNA interaction plays important roles in many cellular processes, and there is an urgent demand for valid methods to monitor the interaction. In view of this, we propose a simple label-free colorimetric platform for the detection of protein–DNA interaction. Protein–DNA couples together with peroxidase-mimicking DNAzyme and exonuclease are elaborately incorporated into an integrated biosensing system. Besides the simplicity and efficiency, the strategy also has a great advantage for its universality in the detection of different protein–DNA couples. In our experiments, effective validation of our approach can be supported by two different protein–DNA couples (estrogen receptor α and nuclear factor kappa B). Experimental results show that the DNAzyme is competent to give rise to evident readout signals to monitor protein–DNA couples. Furthermore, with the substitution of DNA binding sequence in the probe, this method could be extended to a general platform for the detection of protein–DNA interaction.

► A novel colorimetric biosensing platform for the detection of protein–DNA interaction.
► Interaction between ERα/NF-κB and their corresponding binding sequences is studied.
► The biosensing platform is easily-operated, cost-effective and universal.