Synergistic effect of boric acid affinity magnetic materials and multi-hotspot SERS substrates for high sensitivity detection of glucose

In this work, boric acid affinity magnetic materials and Au nanorods capped by Ag (AuNRs@Ag) core-shell structure were used to construct the sandwich structure to obtain surface-enhanced Raman scattering (SERS) sensor for detecting glucose. The AuNRs@Ag modified with 4-mercaptophenylboronic acid (4-MPBA) as SERS substrate, illustrating the efficient electromagnetic enhancement. Moreover, the boric acid affinity magnetic materials (FMNPs) were further functionalized with knife bean lectin as “capture probe”, which illustrated the high adsorption capacity to glucose. The maximum adsorption amount can reach 33.3 mg/g. The conditions for preparing SERS platform as well as glucose detection were optimized. Under the optimal experimental conditions, the detection linear range for glucose is 1.0×10-11 ~ 1.0×10-3 mol/L with a limit of detection (LOD) 1.8×10-12 mol/L (S/N = 3). In addition, the developed SERS sensor was further applied for determination of glucose in human urine with recoveries in the range from 97.5% to 101.5%. As expected, the prepared sandwich SERS sensor was successfully employed to recognize and detect glucose with high sensitivity.