2D MXene-DNA Hybrid Hydrogel for Thrombin Detection: A Versatile Approach for Biomedical Sensing

The delaminated MXene (2D MXene) and DNA hydrogel created enormous opportunities due to their versatility and ability to be tailored for specific applications. MXene offers high aspect ratio morphology and electrical conductivity, while DNA provides stimuli responsiveness and specificity in binding to ligands or complementary sequences. This synergy makes DNA an ideal actuator when combined with 2D MXenes. Present work makes the first effort to combine and exploit them for detecting the thrombin levels; a crucial proteolytic enzyme that plays a pivotal role in regulating blood clotting by cleaving fibrinogen into fibrin and plays a critical role in bleeding disorders such as Haemophilia and Von Willebrand disease. This study introduces a novel hybrid DNA hydrogel by leveraging the properties of 2D MXene with a thiol-modified thrombin binding aptamer (TBA) as a crosslinking agent. The TBA and its complementary DNA oligos are immobilized on 2D MXene sheets, forming a packed hydrogel. Upon thrombin binding, the TBA releases its complementary DNA, resulting in a loosened hydrogel and a change in resistance, which is used as a read-out for thrombin detection. The concept is successfully demonstrated, achieving 90-92% accuracy in detecting thrombin in artificial samples. This robust technique holds promise for biomedical sensing devices, allowing customization for the detection of various target molecules using specific aptamers.