An LF-NMR Biosensor for the Detection of Circulating Tumor Cells Based on Target-Triggered Bioorthogonal Chemistry and Click Chemistry.

Circulating tumor cells (CTCs), crucial biomarkers for monitoring cancer metastasis and prognosis, present significant challenges for detection technologies due to their extremely low abundance in peripheral blood. This study introduces a low-field nuclear magnetic resonance (LF-NMR) biosensor leveraging the synergistic effect of biorthogonal chemistry and click chemistry for CTC detection by a sol-gel phase-transition strategy. Initially, CTCs were targeted and enriched using mucin 1-specific aptamers.

Target-Triggered Enzymatic Cascade LF-NMR Biosensor for the Detection of Circulating Tumor Cells.

A target-triggered, enzymatic cascade-amplified low-field nuclear magnetic resonance (LF-NMR) sensor was developed for the detection of the circulating tumor cell (CTC) A549. A multifunctional two-dimensional bionanomaterial GDA@GOX&DNA1 was designed as the initiator, with FeO@DNA2/Apt as the recognition unit and CaO@MnO as the signal unit. When A549 was present, the aptamer (Apt) detached from the recognition unit, allowing the formation of GDA@GOX&DNA1-DNA2@FeO and triggering the following reactions: (1) glucose oxidase (GOX) catalyzed the reaction between the substrate glucose and oxygen (O) to produce gluconic acid and hydrogen peroxide (HO); (2) the generated acid and HO reacted with MnO, producing signal probes Mn and O; and (3) CaO reacted with the acid, generating HO.