Abstract: Disclosed is a method for detecting aflatoxin B1 based on fluorescent copper nanoparticles, belonging to the technical fields of analytical chemistry, materials science and nano biosensing. In the disclosure, ?-CD@DNA-Cu NMs are prepared by using Y-shaped DNA as a template, ascorbic acid as a reducing agent and ?-CD as a fluorescence stabilizing and enhancing agent. Then, a ratiometric fluorescent probe is constructed based on the ?-CD@DNA-Cu NMs. Finally, the detection of AFB1 with high sensitivity, high selectivity and high accuracy is achieved by using the fluorescent probe. According to the method of the disclosure, in linear ranges of 0.03-10 ppb and 10-18 ppb, a ratio value of I433 nm/I650 nm and a concentration of AFB1 exhibit a good linear relationship respectively, and a limit of detection is 0.012 ppb (S/N=3). Metal ions Ca2+ may be replaced with Yb3+, Y3+, Er3+ and Pt2+, which are also suitable for increasing sensitivity of AFB1 in rice.

Abstract: Disclosed is a method for detecting aflatoxin B1 based on fluorescent copper nanoparticles, belonging to the technical fields of analytical chemistry, materials science and nano biosensing. In the disclosure, ?-CD@DNA-Cu NMs are prepared by using Y-shaped DNA as a template, ascorbic acid as a reducing agent and ?-CD as a fluorescence stabilizing and enhancing agent. Then, a ratiometric fluorescent probe is constructed based on the ?-CD@DNA-Cu NMs. Finally, the detection of AFB1 with high sensitivity, high selectivity and high accuracy is achieved by using the fluorescent probe. According to the method of the disclosure, in linear ranges of 0.03-10 ppb and 10-18 ppb, a ratio value of I433 nm/I650 nm and a concentration of AFB1 exhibit a good linear relationship respectively, and a limit of detection is 0.012 ppb (S/N=3). Metal ions Ca2+ may be replaced with Yb3+, Y3+, Er3+ and Pt2+, which are also suitable for increasing sensitivity of AFB1 in rice.

Abstract: The present disclosure discloses a universal aptamer-based colloidal gold lateral flow test strip for detecting small-molecule substances and belongs to the fields of analytical chemistry, medicine, environment, food safety detection, nano-biosensing and the like. An AuNPs@poly-DNA probe is used for rapidly and sensitively capturing an aptamer, streptavidin sprayed in a test zone and streptavidin-biotin-DNAc sprayed in a control zone do not need to be changed, and another substance can be detected only by changing a nucleic acid chain part of the AuNPs@poly-DNA probe. A universal colloidal gold lateral flow test strip, which is rapid, sensitive and low in cost, has been developed. The test strip method for detecting small-molecule substances is simple, convenient and rapid, and can be used for detection at any time.

Abstract: Disclosed is a method for detecting aflatoxin B1 based on fluorescent copper nanoparticles, belonging to the technical fields of analytical chemistry, materials science and nano biosensing. In the disclosure, ?-CD@DNA-Cu NMs are prepared by using Y-shaped DNA as a template, ascorbic acid as a reducing agent and ?-CD as a fluorescence stabilizing and enhancing agent. Then, a ratiometric fluorescent probe is constructed based on the ?-CD@DNA-Cu NMs. Finally, the detection of AFB1 with high sensitivity, high selectivity and high accuracy is achieved by using the fluorescent probe. According to the method of the disclosure, in linear ranges of 0.03-10 ppb and 10-18 ppb, a ratio value of I433 nm/I650 nm and a concentration of AFB1 exhibit a good linear relationship respectively, and a limit of detection is 0.012 ppb (S/N=3). Metal ions Ca2+ may be replaced with Yb3+, Y3+, Er3+ and Pt2+, which are also suitable for increasing sensitivity of AFB1 in rice.