Hydrogel Grating\nSensors with Boron Affinity and Molecular\nImprinting Effects for Rapid and Sensitive Detection of Tumor Marker\nSialic Acid

Rapid and sensitive detection of the concentration of\nsialic acid\n(SA) in serum is crucial for early tumor screening and prognostic\nassessment; however, it still remains challenging. Here, we propose\na novel kind of hydrogel grating sensor with boron affinity and molecular\nimprinting effects (B-MIP) for the rapid and sensitive detection of\nSA concentration in serum. The hydrogel gratings feature uniform surface\nrelief microstructures and incorporate highly specific recognition\nbinding sites into SA molecules provided by boron affinity and molecular\nimprinting. The periodic nanoridges of hydrogel gratings increase\nthe specific surface area contacting the environmental solution; therefore,\nfast detection can be achieved within 2 min. Upon recognition of SA\nmolecules, the height of hydrogel gratings changes at the nanoscale,\ncausing a change in the diffraction efficiency of the hydrogel gratings.\nThe B-MIP hydrogel grating sensors have highly specific binding sites\nto SA molecules distributed throughout the whole hydrogel and can\npreferentially and selectively recognize and respond to the SA molecules\neven in the presence of interference substances glucose and fructose\nwith high concentrations. The B-MIP hydrogel grating sensors are effectively\napplicable for the rapid and sensitive detection of SA concentrations\nin real serum samples with satisfactory accuracy and precision. Our\napproach provides an excellent strategy to address the current challenges\nin SA detection and provides new insights into the detection of tumor\nmarkers in serum, thereby opening up new ways to accurately detect\ncomplex biological samples in analytical science.