Solvent Regulation Enhanced Aggregation-Induced Electrochemiluminescence of Piperazine-Functionalized Carbon Dot Aggregates for Ultrasensitive Detection of Deoxynivalenol

The environmental contamination caused by deoxynivalenol (DON) has become an emerging public health issue, and its sensitive and accurate analysis is crucial as its trace amounts and microchange in environmental monitoring and management. Here, piperazine-functionalized carbon dot aggregates (P-CDAs) with obvious aggregation-induced electrochemiluminescence (AIECL) properties strengthened by solvent regulation were synthesized, based on which an ECL aptasensor was constructed for the efficient detection of DON. In addition to the surface states optimizing originated from piperazine modification, the aggregation of the P-CDs was further facilitated through solvent regulation, which could directly influence the aggregated process and final ECL performance but was usually neglected in the precious AIECL study. Thus, selecting specific solvents and proportion control was very important for the AIECL. It showed that the P-CDAs could be excited more easily because of the reduced band gap energy and exhibited an improved and red-shifted ECL signal wavelength (603 nm) in ethanol/water (9:1 volume ratio). In addition, to achieve ultrasensitive detection of low-abundance DON, a DNA zipper structure-mediated localized hybridization chain reaction (Z-L-HCR) induced dual-output strategy was constructed. The proposed Z-L-HCR minimized the free diffusion of hairpin DNA, thereby enhancing the reaction rate. Simultaneously, both Z-L-HCR and dual-output mode reduced background signals effectively, realizing the ultrasensitive detection of DON with a detection limit of 0.112 fg/mL. In summary, surface modification and solvent regulation hold significant potential for enhancing the AIECL performance of carbon dots, and the proposed ECL aptasensor provides a reliable detection method for environmental monitoring and food safety.