Highly sensitive protein detection based on DNAzyme cycling activated surface assembly of peptide decorated nanoparticles

In this work, a new method for the sensitive detection of proteins has been developed by combining the highly efficient DNAzyme cycling processing of DNA with nanoparticles which have an affinity for DNA. Specifically, DNAzymes are designed to be activated after recognition between the target protein and its aptamer, prehybridized with a DNAzyme sequence. In the meantime, DNAzyme substrates are pre-modified on an electrode surface so as to expose their 5' phosphate end to conjugate with zirconia nanoparticles (ZrNPs), which have strong phosphoric affinity. The nanoparticles are also decorated with a large amount of signal molecule, peptide GHK. Consequently, a greatly amplified electrochemical signal can be achieved for the assay of the target protein. In addition to high sensitivity and simplicity, this strategy is also versatile, because it can easily be adapted to assay a large spectrum of targets simply by changing the sequence of the aptamer. Thus it holds great potential for the development of ultrasensitive biosensors in clinical bioanalysis. (C) 2016 Elsevier B.V. All rights reserved.