A novel signal amplified electrochemiluminescence biosensor based on MIL-53(Al)@CdS QDs and SiO2@AuNPs for trichlorfon detection

An ultrasensitive electrochemiluminescence (ECL) biosensor was developed based on MIL-53(Al)@CdS QDs and SiO2@AuNPs for trichlorfon detection. Metal-organic frameworks (MOFs) were used as a loading platform that provided a large surface area to load targets and modified materials onto the electrode. At the same time, SiO2@AuNPs loaded plenty of AuNPs which effectively increased ECL resonance energy transfer between CdS QDs, so the ECL signal was inhibited and made signal amplified. In the range of 10-11-10-4 M, the ECL response presented linear relationship to the concentration (logarithm) of trichlorfon, and the detection limit is 5.1×10-12 M (S/N=3). When the biosensor was applied to the detect trichlorfon in lettuce, broccoli, cucumber, and chives, the recoveries obtained from spiked samples were 97%-105%, 102%-104%, 100%-104%, and 98%-104%, respectively. Thus, this novel ECL biosensor presented a potential application for the analysis of trichlorfon in food samples.