Abstract: A nanozyme material and a preparation method thereof are provided. In the preparation method, Prussian blue (PB) is used to regulate the peroxidase activity of Fe,NA/CDs, and then gold nanoparticles are synthesized with Fe,NA/CDs as a reducing agent and a stabilizing agent. The nanozyme material has both a peroxidase activity and a Raman enhancement effect, which can be used for nanozyme-based surface-enhanced Raman spectroscopy (SERS). An embodiment of the present disclosure also provides a method for rapidly detection of a Pb2+ ion, which is based on a color change or an additional Raman SERS signal generation caused by nanozyme oxidation. Such sensing signals (colorimetric and SERS analysis) are derived from a catalytic oxidation reaction of ABTS or TMB, while the presence of Pb2+ specifically inhibits the oxidation, such that the rapid detection of Pb2+ can be achieved.

Abstract: A visual loop-mediated isothermal amplification (LAMP) method for a rapid test of tobacco includes: extracting a genomic DNA of the tobacco, designing primers, establishing a LAMP reaction system, and optimizing the LAMP reaction system. The present disclosure designs the LAMP primers according to a conserved region of a screened tobacco-specific Ntsp151 genomic sequence, and establishes the LAMP method based on color determination. The present disclosure can rapidly identify flue-cured tobacco leaves, finished cigarettes, and tea cigarettes, and achieves a detection limit of 200 copies per reaction. The test results of the LAMP method for non-tobacco samples are negative, indicating that the LAMP method has high specificity. Compared with the quantitative polymerase chain reaction (qPCR) method, the LAMP method has a coincidence rate of 96.7%, but the LAMP method only needs about 1 h to obtain the results.