Influence of gold nanoparticles in different aggregation states on the fluorescence of carbon dots and its application

Herein, gold nanoparticles (Au NPs) in solution protected by various concentration of DNA at different aggregation states were found to have different quenching effect to the fluorescence of carbon dots (CDs). Au NPs wrapped up in more amount of DNA were able to quench the fluorescence of CDs more effectively, and vice versa. Based on this phenomenon, a facile and novel fluorescence sensing platform without labeling was constructed by designing the sequence of DNA as the aptamer of the detection target. With the addition of specific molecule, taking acetamiprid as representative, DNA was prior to bind with target and the Au NPs became less protected, leading to the fluorescence recovery of the CDs. Experimental results showed that the fluorescence of CDs was linearly recovered by acetamiprid in the concentration range of 7.8 × 10 −9 –1.4 × 10 −6  mol/L, with the detection limit of 1.5 × 10 −9  mol/L. This promising sensor might provide a new aspect for exploring the versatile application of CDs in various fields.