Multimode Signal Detection Of Aflatoxin B1 Based On Prussian Blue Nanoparticles

In recent years,food safety problems caused by mycotoxins have frequently entered the public’s view,posing a serious threat to the life and health of human and animals.Aflatoxin B1（AFB1）is the most toxic mycotoxin.The rapid,accurate and highly sensitive detection of AFB1 in food is of great significance to protect human life and health.Among many methods for AFB1 detection,the biosensor method based on nanomaterials has the advantages of high efficiency,convenience and sensitivity,and the biosensor method based on aptamer（APT）has the advantages of high specificity and low cost.However,these methods generally have the limitation of single signal output and low accuracy.It is expected to further improve the accuracy of the detection results by combining the advantages of APTS and multimode biosensors.In view of this,in this paper,taking prussian blue nanoparticles（PBNPs）and gold nanoclusters（AuNCs）as the main body,PBNPs-PEI@AuNCs was synthesized,and a new APT biosensor detection method based on PBNPs-PEI@AuNCs was developed to realize the accurate and highly sensitive detection of AFB1.The main results are as follows:1.PBNPs-PEI@AuNCs nanomaterials were synthesizedCarboxyl modified PBNPs were synthesized with citric acid and carboxyl modified AuNCs were synthesized with glutathione.Using PBNPs as carrier and PEI as crosslinking agent,AuNCs were combined on the surface of PBNPs by carboxyammonia reaction to synthesize PBNPs-PEI@AuNCs.PBNPs-PEI@AuNCs was composed of AuNCs uniformly coated on the surface of PBNPs.The particles are cubic in shape and the size was about 50±5 nm.PBNPs-PEI@AuNCs has triple characteristics of emitting fluorescence at 600 nm after decomposition by Na OH,catalyzing color change of 3,3’,5,5’-tetramethyl benzidine and hydrogen peroxide reaction and converting 808 nm NIR laser energy into heat.2.A multimode signal detection strategy for AFB1 based on PBNPs-PEI@AuNCs was constructedPBNPs-PEI@AuNCs combined with AFB1 specific Apt,the PBNPs-PEI@AuNCs@Apt probe integrating target acquisition and signal output was prepared,which can output triple signals of fluorescence,colorimetry and heat production.The linear relationship between the change of triple signal and AFB1concentration was studied.The linear range of fluorescence signal was 10^-14～10^-8g/m L and the detection limit was 0.64×10^-14g/m L.The linear range of colorimetric signal was 10^-14～10^-8g/m L and the detection limit was 0.55×10^-14g/m L.The linear range of the obtained thermal signal was 10^-12～10^-8g/m L and the detection limit was0.96×10^-12g/m L.The experimental results showed that the method meet the requirements of analysis and detection by standard addition recovery,actual sample analysis and comparison with the detection results of commercial El SA kit.