Photothermal enhanced pressure sensing based on multifunctional Nb2C MXene for portable detection of interleukin-6

Herein, a sensitive and portable pressure-based biosensor was fabricated to accurately assess maternal plasma interleukin-6 (IL-6) levels for achieving the timely monitoring of preeclampsia. Initially, IL-6 modified Nb2C MXene with excellent physicochemical properties as a multi-functional and powerful biological probe was introduced into the paper-based analytical device via competitive-type immunoassay. As expected, the outstanding peroxidase-like performance of Nb2C MXene triggered the decomposition of hydrogen peroxide and produced the pressure signal. More interestingly, the gas production reaction could be considerably accelerated under the irradiation of 808 nm near-infrared light resulted from the brilliant photothermal characteristic and black-body effect of Nb2C MXene, which induced a significantly enhanced pressure change. Therefore, the synergistic activation and sensitization capabilities of Nb2C MXene on pressure signals make the sensing platform demonstrate satisfactory analytical performances for IL-6 detection including wide linear range from 10−5 to 1 ng/mL, low detection limit of 3.33 × 10−6 ng/mL, high selectivity, good recovery and acceptable repeatability. Evidently, this ingenious strategy not only enriches the application scenarios of MXene, but also provides valuable guidance for developing intelligent and convenient in situ analytical device.