An innovative label-free electrochemical aptamer sensor: utilizing Ti₃C₂T_x/MoS₂/Au NPs for accurate interleukin-6...

In the medical field, changes in interleukin-6 (IL-6) concentration serve as essential biomarkers for monitoring and diagnosing various conditions, including acute inflammatory responses such as those seen in trauma and burns, and chronic illnesses like cancer. This paper detailed a label-free electrochemical aptamer sensor designed for IL-6 quantification. A composite material consisting of Ti₃C₂T_x and MoS₂ was successfully synthesized to fabricate this sensor. The synergistic effect of MoS₂'s catalytic action on hydrogen peroxide (H₂O₂), used as a signalling marker, when combined with the exceptional conductivity and large specific surface area of Ti₃C₂T_x, not only enables an increased loading of MoS₂ but also significantly boosts the electrochemical response. The in situ-reduced Au NPs provided stable immobilization sites for DNA aptamers (DNA_apt) and facilitated electron transfer, ensuring accurate IL-6 recognition. Under optimal conditions, the aptamer sensor exhibited a wide linear range (5 pg/mL to 100 ng/mL) and a low limit of detection (LOD) of 2.9 pg/mL. Its sensing performance in human serum samples highlights its potential as a promising clinical analysis tool.