MXene nanosheet loaded gold nanocluster catalytic amplification–aptamer SERS quantitative assay platform for isocarbophos

Abstract

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.