Research On Detection Of Packaging Risk Substances Based On Aptamer Recognition

Packaging,an important and indispensable part.In particular,the packaging of food plays a vital role in the shelf life of food The safety of packaging materials affets the safety of food.The safety of food is related to human life and health.Therefore,the detection of risk substances in packaging materials has become a hot research direction.Due to the raw materials and the manufacturing process,the packaging materials will be polluted by heavy metals.Among them,cadmium pollution-seriously damages the health of consumers.The common "pain" and "cadmium rice" were caused by cadmium pollution.The detection of Cd(Ⅱ)in food packaging materials has become very meaningful.This topic develops a highly selective and sensitive method for Cd(Ⅱ)detection based on aptamer and gold nanoparticles(AuNPs)combined with colorimetric-smartphone readings.Using aptamers as elements to identify Cd(Ⅱ),gold nanoparticles(AuNPs)as color-developing elements,indirectly through the dual action of cationic polymer polydiallyldimethylammonium chloride(PDDA).The degree of coloration of AuNPs detected different concentrations of Cd(Ⅱ),combining the colorimetric method with the smartphone color collection app to turn the visualization into digital and better read the results.In order to enable the method to detect Cd(Ⅱ)under optimal conditions,the reaction time of polydiene dimethylammonium(PDDA)with AuNPs,the amount of PDDA,the incubation time of aptamer and PDDA,and the concentration of aptamer were optimized.condition.Under optimal conditions,the color and R value of the solution showed a concentration dependence on Cd(Ⅱ).The proposed method has a linear range of 1-400 ng/mL(R~2=0.9794).The method has been successfully applied to the test and quantification of Cd(Ⅱ)in water and rice samples.The method was verified by the method and the results were completely consistent with those measured by atomic absorption spectrometer.Therefore,this low-cost colorimetric method showed its potential application in smart phone vision or quantitative detection,and it was also very potential to be applied to other analytes.