Search

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 cells mL −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. [ABSTRACT FROM AUTHOR]

Breast cancer is the most common type of malignant tumor in women. Recently, it has been shown that detection of breast cancer tumor cells outside the primitive tumor is an effective early diagnosis with great prognostic and clinical utility. For this purpose, we developed a signal-on fluorescence aptasensor for label-free, facile and sensitive detection of MCF-7 breast cancer cells. Due to target–aptamer specific recognition and single-stranded DNA-sensitized luminescence of terbium (III), the proposed aptasensor exhibits excellent sensitivity with detection limit as low as 70 cells mL − 1 . Compared with common organic dyes and the emerging nano-technological probes, the combination of terbium (III) and single-stranded DNA signal probe (Tb 3+ –SP) serves as a more powerful bio-probe because of its stable optical property, good biocompatibility and free from complex synthesis. The feasibility investigations have illustrated the potential applicability of this aptasensor for selective and sensitive detection of MCF-7 breast cancer cells. Moreover, this proposed aptasensor can be also extended for the determination of other tumor cancers or bio-molecules by altering corresponding aptamers. Taken together, this easy-to-perform aptasensor may represent a promising way for early screening and detection of tumor cancers or other bio-molecules in clinical diagnosis. [ABSTRACT FROM AUTHOR]