A novel aptamer RRS assay platform for ultratrace melamine based on COF-loaded Pd nanocluster catalytic amplification.

Two COFs of BzBD and BzBD loaded Pd nanoclusters (BzBD Pd) were prepared using 1,3,5-benzenetricarboxaldehyde (Bz), benzidine (BD) and CO reducing agent, and were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), infrared spectroscopy (IR) and other techniques. BzBD Pd can strongly catalyze the new and stable Au@NiP nanoreaction that exhibit a strong resonance Rayleigh scattering (RRS) peak at 538 nm and a surface plasmon resonance (SPR) absorption peak at 395 nm, and the sensitive and facile RRS technique was used to study the indicator reaction. Combining the nanocatalytic amplification reaction with specific aptamer (Apt) of some target molecules such as melamine (ML), urea (UR) and bisphenol A (BPA), a simple, sensitive and selective Apt RRS assay platform was established. The linear range of the RRS detection platform for melamine is 0.0025–0.04 nmol/L, and the detection limit (DL) is 1.96 × 10−4 nmol/L. In addition, ML in real sample was analyzed, the stability of BzBD, BzBD Pd , PdNPs and the catalytic mechanism of COF Pd were also considered. [Display omitted] • A new COF doped with Pd nanoclusters (COF Pd) was synthesized. • COF Pd can strongly catalyze the Au@NiP alloy reaction. • A RRS platform was established coupling Au@NiP alloy nanoreaction with aptamer. • The RRS platform has high sensitivity, selectivity and accuracy. [ABSTRACT FROM AUTHOR]