A logic gate for fluoride anion detection based on carbon dots/gold nanoparticles

Abstract

A selective logic gate sensor for fluoride anion is first fabricated based on carbon dots/gold nanoparticles hybrid material using 3-mercapto-l,2-propanediol (MP) as the bridge. First, 3-aminophenylboronic acid is chosen as the precursor to fabricate boronic acid decorated carbon dots (b-CDs). Then, b-CDs@MP-gold nanoparticles aggregation is formed by taking advantage of MP as a bridge. As for the occurrence of FRET behavior from b-CDs to gold nanoparticles, the fluorescent signal of b-CDs@MP-Au NPs aggregation based sensor quenches remarkably, called as OFF state. However, fluoride anion binds completely with synthesized b-CDs and induces b-CDs to break away from the surface of gold nanoparticles, activating fluorescent signal, named as ON state. As the concentration of fluoride anion increases, the fluorescence signal of the sensor gradually enhances. The fluorescent response for fluoride anion detection is in the linear range from 9 μM to 117 μM with the detection limit of 1.5 μM. Moreover, the b-CDs@MP-Au NPs based sensor is operated as a logic gate at the molecular level. The experimental results indicate that our present approach can be adapted for establishing the chemical logic gate for the fluoride anion. Furthermore, our proposed strategy holds great potential application in environmental monitoring.