A novel electrochemical method based on screen-printed electrodes and magnetic beads for detection of trinucleotide repeat sequence d(CAG)n

Electrochemical sensors have been highly developed and play an important role in the early diagnosis of different diseases. In this work, a simple and rapid electrochemical method was developed for the quantitative detection of a trinucleotide repeat (TNR) sequence d(CAG)n based on magnetic beads and screen-printed carbon electrodes. Their combination greatly simplified the operation process. The intensity of the electrochemical signal was linearly correlated against the concentration of the TNR sequence d(CAG)n in the range from 100 pM to 1 μM, with a limit of detection as low as 24 pM. Furthermore, the number of repeats of the TNR sequence d(CAG)n could be detected and also showed a good linear relationship. The proposed method provides a promising rapid and simple method for the detection of a CAG TNR sequence for point-of-care testing in clinical applications.