Efficient nanocatalytic amplification of COF-loaded liquid crystal coupling with free-label aptamer to determine trace small molecular drugs by SERS quantitative strategy

Abstract

Novel nanomaterial with highly catalysis and stability are attracting analyst, that can be used to amplify signal to develop highly sensitive nanoanalysis method. Herein, a stable and highly catalytic covalent organic framework loaded-HB (COFHB) was synthesized, using 1, 3, 5-benzenetricarboxaldehyde (Bz), benzidine (BD), and 4-hexyloxybenzoicacid (HB) liquid crystals as precursors, and it has been characterized in detail by TEM, XRD and molecular spectral techniques. Using the slope procedure to evaluate nanocatalysis, COFHB exhibits the strongest catalysis of mandelic acid-HAuCl4 nanogold reaction to generate gold nanoparticles (AuNPs), and the generated AuNPs have strong resonance Rayleigh scattering (RRS) and surface plasmon resonance absorption (Abs) signals. When VB4r is added as a molecular probe, it exhibits a strong surface-enhanced Raman scattering (SERS) signal. This highly sensitive nano-indicator reaction can be coupled with the recognition ability of ampicillin sodium-specific aptamer (AptAMP) to fabricate a highly sensitive and selective SERS/RRS/Abs trimode aptamer sensoring platform for the detection of AMP, and a reasonable COFHB catalytic amplification mechanism was proposed. In addition, the nanocatalytic amplification aptamer SERS platform can also be used for the detection of other small molecular drugs including sulfadimethoxine (SDM), tetracycline (TEC) and oxytetracycline (OTC).