Abstract: The disclosure discloses a nicotinamide dummy template surface molecularly imprinted polymer, a preparation method and application thereof, and belongs to the technical field of chemical materials. The preparation method of the disclosure includes the steps of preparing a modified silica gel carrier, preparing a dummy template surface molecularly imprinted polymer and the like. The disclosure uses nicotinamide, a structural analogue of imidacloprid and acetamiprid, as a dummy template to prepare a silica gel surface molecularly imprinted polymer. The polymer not only can effectively avoid pollution caused by the leakage of template molecules, but also can specifically remove imidacloprid and acetamiprid from water-soluble tea extracts. The removal rate of imidacloprid and acetamiprid is greater than 96% and 93%, respectively, and the loss of tea polyphenols in the extracts is less than 10%.

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 provides a functional beverage of dark tea with zero energy for reducing weight and lipid and a preparation method thereof, and relates to the technical field of processing health-promoting beverage. The functional beverage includes 1.5-3.5 parts of dark tea, 0.3-0.7 parts of mulberry leaf, 0.1-0.5 parts of lotus leaf, 0.1-0.3 parts of stevia leaf, and 95.4-97.4 parts of purified water. The preparation process thereof includes treatment of raw materials, circulatory microwave extraction, static settlement, membrane ultrafiltration, and ultra-high temperature instantaneous sterilization (UHT). Compared with the prior art, the functional beverage uses purely natural herb plants without any additives. The obtained product has zero sugar while has the effects of quenching thirst and reducing weight and lipid. Key technologies such as integrated formula, circulatory microwave extraction, and membrane ultrafiltration enable the best flavor and efficacy of the beverage.

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 disclosure discloses a nicotinamide dummy template surface molecularly imprinted polymer, a preparation method and application thereof, and belongs to the technical field of chemical materials. The preparation method of the disclosure includes the steps of preparing a modified silica gel carrier, preparing a dummy template surface molecularly imprinted polymer and the like. The disclosure uses nicotinamide, a structural analogue of imidacloprid and acetamiprid, as a dummy template to prepare a silica gel surface molecularly imprinted polymer. The polymer not only can effectively avoid pollution caused by the leakage of template molecules, but also can specifically remove imidacloprid and acetamiprid from water-soluble tea extracts. The removal rate of imidacloprid and acetamiprid is greater than 96% and 93%, respectively, and the loss of tea polyphenols in the extracts is less than 10%.

Abstract: The present disclosure provides a functional beverage of dark tea with zero energy for reducing weight and lipid and a preparation method thereof, and relates to the technical field of processing health-promoting beverage. The functional beverage includes 1.5-3.5 parts of dark tea, 0.3-0.7 parts of mulberry leaf, 0.1-0.5 parts of lotus leaf, 0.1-0.3 parts of stevia leaf, and 95.4-97.4 parts of purified water. The preparation process thereof includes treatment of raw materials, circulatory microwave extraction, static settlement, membrane ultrafiltration, and ultra-high temperature instantaneous sterilization (UHT). Compared with the prior art, the functional beverage uses purely natural herb plants without any additives. The obtained product has zero sugar while has the effects of quenching thirst and reducing weight and lipid. Key technologies such as integrated formula, circulatory microwave extraction, and membrane ultrafiltration enable the best flavor and efficacy of the beverage.