TY - JOUR AU - Li, Yongqiang AU - Shi, Zhifeng AU - Shang, Liuyang AU - Tao, Quan AU - Tang, Qisheng AU - Krause, Hans-Joachim AU - Yang, Siwei AU - Ding, Guqiao AU - Dong, Hui TI - Graphene quantum dots-based magnetic relaxation switch involving magnetic separation for enhanced performances of endoglin detection using ultra-low-field nuclear magnetic resonance relaxometry JO - Sensors and actuators / B VL - 380 SN - 0925-4005 CY - Amsterdam [u.a.] PB - Elsevier Science M1 - FZJ-2023-01641 SP - 133389 - PY - 2023 AB - Magnetic relaxation switches (MRS) based on target-induced state changes of magnetic nanoparticles are vital approaches for biomolecule detection in in vitro diagnosis. Recently, magnetic graphene quantum dots have been employed as magnetic probes instead of iron oxide nanoparticles and showed high sensitivity. Introducing magnetic separation into an MRS assay before the relaxometry measurements can enhance the sensitivity, elevateaccuracy, and expand the linear region. In this work, magnetic separation-assisted MRS was developed to detect endoglin utilizing iron oxide as the magnetic carrier and magnetic graphene quantum dots as the magnetic probe. The assay possesses a broad linear region from 5 ng/mL to 50 μg/mL and a sensitive limit of detection of 1.3 ng/mL, which is two orders of magnitude lower than that of MRS without magnetic separation. The high accuracy and consistency have been proved for endoglin (CD105) detection in real samples. This graphene quantum dotbased MRS involving magnetic separation provides a new route for enhancing the sensitivity and accuracy of biomolecule detection. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000979418700001 DO - DOI:10.1016/j.snb.2023.133389 UR - https://juser.fz-juelich.de/record/1005796 ER -