A signal amplification electrochemical aptasensor for the detection of breast cancer cell via free-running DNA walker.

Herein, a signal magnification electrochemical aptasensor for the detection of breast cancer cell via free-running DNA walker is constructed. Theoretically, just one DNA walker, released by target cell-responsive reaction, can automatically cleave all D-RNA (a chimeric DNA/RNA oligonucleotide with a cleavage point rArU) anchored on electrode into shorter produces, giving rise to considerably detectable signal finally. Under the optimal conditions, the electrochemical signal decreased linearly with the concentration of MCF-7 cell. The linear range is from 0 to 500 cells mL−1 with a detection limit of 47 cellsmL−1. In a word, this approach may have advantages over traditional reported DNA machines for bioassay, particularly in terms of ease of operation, cost efficiency, free of labeling and of complex track design, which may hold great potential for wide application.