โครงการเซนเซอร์เชิงแสงความไววิเคราะห์สูง อาศัยหลักการขยายสัญญาณด้วยเทคนิค catalyzed hairpin assembly สําหรับการตรวจวัดไมโครอาร์เอ็นเอ

Abstract

A DNA based biosensor was developed for short oligonucleotide detection, such as microRNA, a biomarker for some types of cancer. The short oligonucleotides are present at trace level in biological samples, and with the limit of 25 nucleotides in length, the amount cannot be amplified with the polymerase chain reaction (PCR) technique. Therefore this project utilized the doubly catalyzed hairpin assembly (CHA) technique to amplify short oligonucleotides in conjunction with the Förster resonance energy transfer (FRET) technique. From the results, it was found that the limit of detection (LOD) of the sensor is at 3.23 nM with only 30 minute incubation time. Despite the fact that the current LOD is still too high to be used straightforwardly to detect microRNA in real samples, it is still usable when combined with a proper sample pre-concentration technique. Furthermore we are improving the sensor’s performance by incorporating novel nanomaterials and expect that the LOD will soon be low enough to be used directly.