MXene nanosheet loaded gold nanocluster catalytic amplification-aptamer SERS quantitative assay platform for...

The traditional preparation of MXeneTi₃C₂ is complicated. Two-dimensional MXeneTi₃C₂ nanosheets were prepared via in-situ generation of HF etching Ti₃AlC₂ under the microwave irradiation. Gold nanocluster doped nanosheets sol (MXene@Au) with excellent stability and strong catalysis was synthesized with no product residue reducer CO. MXene@Au nanosol can catalyze mandelic acid-HAuCl₄ to produce gold nanoparticles, which can be traced via resonance Rayleigh scattering (RRS) and surface-enhanced Raman scattering (SERS). Coupled the dual-mode nanocatalytic indicator reaction with aptamer reaction, a high sensitivity, selectivity, facile SERS/RRS dual-mode biosensnoring assay platform has been constructed for isocarbophos (ICP). The linear range of SERS was 1.0 × 10^-3-2.5 × 10^-2 nmol/L, with a detection of limit 4.5 × 10^-5 nmol/L (S/N = 3). It has been used to detect ICP in water samples, with a good recovery (95.5-104%) and a good relative standard deviation (5.2-9.6%). This new nanocatalytic amplification biosensoring strategy can also assay other organic pesticides including malathion, glyphosate, profenofos and carbendazim. In addition, the nanocatalytic mechanism was investigated.