Mesoporous silica thin film mechanized with a DNAzyme-based molecular switch for electrochemical biosensing

•Label-free electrochemical biosensor for Cu(II) and ascorbic acid•DNAzyme-based molecular switch as biosensing mechanism•Gold patterned with mesoporous silica thin films for the DNAzyme-controlled diffusion of Fe(CN)63 −/4 −

A novel electroanalytical strategy for copper and ascorbic acid detection was developed by using a nanostructured electrode surface mechanized with a DNAzyme-based molecular gate. This sensing interface was constructed by first electrodeposition of a mesoporous silica thin film on Au electrodes and further assembly of a Cu(II)-specific DNAzyme. The biosensing assay was based on the Cu(II) and ascorbic acid responsible activation of the DNAzyme, which acted as a molecular switch able to control the diffusion of the Fe(CN)63 −/4 − electrochemical probe through the nanochannels of the mesoporous film.

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