A new di-recognition and di-functional nanosurface aptamer molecularly imprinted polymer probe for trace glyphosate with SERS/RRS/Abs trimode technique

A new di-recognition nitrogen-doped carbon dot nanosurface aptamer molecularly imprinted polymer (CD NAg @MIPApt) nanocatalytic di-functional probe was prepared by microwave irradiation . The probe was utilized nitrogen-doped silver carbon dots (CD NAg ) as the matrix, glyphosate (Gly) as the template molecule, α-methyl acrylate as the monomer , ethylene glycol dimethacrylate as the cross-linker, and aptamer as the biorecognition element. It could not only recognize Gly but also exhibits catalytic amplification function. It was found that CD NAg @MIPApt catalyzed the redox reaction of polyethylene glycol 400 (PEG400)-AgNO 3 to generate silver nanoparticles (AgNPs). The AgNPs indicator component exhibit the effects of surface-enhanced Raman scattering (SERS), resonance Rayleigh scattering (RRS) and surface plasmon resonance absorption (Abs). In the presence of Gly, it binds to the surface imprinted site of CD NAg @MIPApt, to reduce AgNPs generation due to the catalytic activity of CD NAg @MIPApt decreasing. Thus, the SERS/RRS/Abs signal values decreased linearly. The linear ranges of SERS/RRS/Abs assay were 0.1–2.5 nM, 0.25–2.75 nM and 0.5–5 nM respectively. The detection limits were 0.034 nM, 0.071 nM and 0.18 nM Gly. • A new CD NAg @MIPApt probe with di-recognition and di-function was prepared. • Apt was not only enhanced the sensitivity but also improved the selectivity. • The probe exhibits strong catalysis of the new nanoreaction to form AgNPs. • The in situ generated AgNPs are of strong SERS, RRS and Abs effects. • A new, simple, selective and sensitive trimode method for Gly was established.