Heidarian Somayeh, Takbiri Osgoei Laya, Zare Karizi Shohreh, Amani Jafar, Arbabian Sedigheh
Department of Biology, Faculty of Biological Science, North Tehran Branch, Islamic Azad University, Tehran, Iran.
Department of Microbiology, Faculty of Biological Science, North Tehran Branch. Islamic Azad University, Tehran, Iran.
Iran J Pharm Res. 2024 Mar 30;23(1):e144368. doi: 10.5812/ijpr-144368. eCollection 2024 Jan-Dec.
The abnormal expression of microRNA (miRNA) influences RNA transcription and protein translation, leading to tumor progression and metastasis. Today, reliably identifying aberrant miRNA expression remains challenging, especially when employing quick, simple, and portable detection methods.
This study aimed to diagnose and detect the miR-21 biomarker with high sensitivity and specificity.
Our detection approach involves immobilizing ROX dye-labeled single-stranded DNA probes (ROX-labeled ssDNA) onto MWCNTs to detect target miRNA-21. Initially, adsorbing ROX-labeled ssDNA onto MWCNTs causes fluorescence quenching of ROX. Subsequently, introducing its complementary DNA (cDNA) forms double-stranded DNA (dsDNA), which results in the desorption and release from MWCNTs, thus restoring ROX fluorescence.
The study examined changes in fluorescence intensities before and after hybridization with miRNA-21. The fluorescence emission intensities responded linearly to increases in miR-21 concentration from 10 to 3.2 × 10 M. The developed fluorescence sensor exhibited a detection limit of 1.12 × 10 M.
This work demonstrates that using a nano-biosensor based on carbon nanotubes offers a highly sensitive method for the early detection of colorectal cancer (CRC), supplementing existing techniques.
微小RNA（miRNA）的异常表达会影响RNA转录和蛋白质翻译，导致肿瘤进展和转移。如今，可靠地识别异常的miRNA表达仍然具有挑战性，尤其是在采用快速、简单且便携的检测方法时。
本研究旨在高灵敏度和特异性地诊断和检测miR-21生物标志物。
我们的检测方法包括将羧基四甲基罗丹明（ROX）染料标记的单链DNA探针（ROX标记的ssDNA）固定在多壁碳纳米管（MWCNTs）上，以检测目标miRNA-21。首先，将ROX标记的ssDNA吸附到MWCNTs上会导致ROX荧光猝灭。随后，引入其互补DNA（cDNA）形成双链DNA（dsDNA），这会导致从MWCNTs上解吸和释放，从而恢复ROX荧光。
该研究检测了与miRNA-21杂交前后荧光强度的变化。荧光发射强度对miR-21浓度从10到3.2×10 M的增加呈线性响应。所开发的荧光传感器的检测限为1.12×10 M。
这项工作表明，使用基于碳纳米管的纳米生物传感器为早期检测结直肠癌（CRC）提供了一种高度灵敏的方法，补充了现有技术。
