Synthesis and Characterization of Nano-Biosensor Based on Graphene Oxide Nanosheets (Au NPs- PANI Polymer-GO) Through Electrochemical Method for Early and Sensitive Detection of Breast cancer miRNA-21 biomarker without Labeling
نویسندگان
1 Termiz University of Economics and Service, Termez, Surxondaryo, Uzbekistan
2 Department of Medical Laboratories Technology, Al-Nisour University College, Baghdad, Iraq
3 Al-Zahrawi University College, Karbala, Iraq
4 Mazaya University College, Iraq
5 Samarkand State Medical University, Samarkand, Uzbekistan
6 Department of Medical Physics, Al-Turath University, Baghdad, Iraq
7 College of Pharmacy, Ahl Al bayt University, Kerbala, Iraq
8 Al-Manara College for Medical Sciences, University of Manara, Maysan, Iraq
9 College of Health and Medical Technologies, National University of Science and Technology, Dhi Qar, Iraq
10 Department of Folk Medicine, Occupational Diseases and Allergology, Bukhara State Medical Institute Named After Abu Ali Ibn Sino, Bukhara, Uzbekistan
11 Department of Pedagogy, Karshi State University, Karshi, Uzbekistan
12 Department of Internal Medicine N2 and Endocrinology, Tashkent Medical Academy, Tashkent, Uzbekistan
doi
10.22052/JNS.2026.01.029چکیده
Early detection of circulating miRNA-21 is pivotal for timely intervention in breast cancer, yet current assays remain labor-intensive or amplification-dependent. Here we introduce a label-free electrochemical nano-biosensor constructed by decorating graphene oxide nanosheets with an ultrathin polyaniline skin and densely packed gold nanoparticles (Au NPs–PANI–GO). The architecture synergizes the π-rich scaffold of GO, the redox conductivity of PANI, and the catalytic amplification of Au NPs, furnishing an interface that transduces miRNA hybridization into a sub-ohm impedance change without external redox mediators. Experimental parameters probe density (1.0 µM), hybridization time (30 min), ionic strength (0.10 M NaCl), temperature (25 °C) and pH (7.4) were sequentially optimized through one-factor-at-a-time screening (Table 1). Under these conditions the sensor exhibits a linear dynamic range spanning 10 aM to 1 nM (R² = 0.998) with a 3.4 aM detection limit (≈20 copies per 10 µL droplet). Single-base-mismatch discrimination exceeds 92 %, and recoveries in undiluted human serum range from 96 % to 104 % (Table 4). Inter-day RSD is <5 % over 21 days of storage at 4 °C. The assay proceeds in 30 min, requires no RNA extraction or enzymatic amplification, and uses low-cost screen-printed electrodes, offering a pragmatic route toward point-of-care screening of breast-cancer-specific miRNA-21.
