A Sensitive Immunochromatographic Test Strip Based on Hydrophobic Quantum Dots Incorporated into Mg/Fe Nanoflowers for HCG Detection

As the most widely used disposable paper-based diagnostic tool in world, immunochromatographic test strips (ICTS) have occupied more and positions field of rapid diagnosis due to their ease operation affordability. Therefore, development an easily prepared, sensitive, accurate signal reporter is great significance for detection some low-abundance biomarkers clinical diagnosis. Herein, Mg/Fe layered double hydroxide nanoflowers (MF NFs) were selected as adsorption templates sulfhydryl-functionalized, followed by one-step loading hydrophobic CdSe/ZnS quantum dots organic phase via a metal-thiol covalent bond. After coating with branched polyethyleneimine (PEI), novel ICTS fluorescent was prepared. The modification PEI not only improved hydrophilicity MF@CdSe/ZnS NFs but also introduced amino functional groups on surface subsequent conjugation antibodies. X-ray photoelectron spectroscopy, UV-vis absorption, diffraction, fluorescence infrared spectroscopy characterize composition NFs. Under optimal experimental conditions, range MF@CdSe/ZnS@PEI-ICTS model analyte HCG 0.1–500 mIU/mL, limit (LOD) reached 0.1 mIU/mL. potential practical application validated spiked healthy human serum, showing overall recoveries between 90.48 116.1% coefficients variation that ranged from 3.66 12.91%.