RecJf exonuclease-assisted signal amplification for the sensitive detection of di(2-ethylhexyl)phthalate by a Pd@Au NB labeled electrochemical aptasensor based on Au@Ni-CoHNB/PEI-g-C3N4

Abstract

Herein, a gold–palladium core–shell nanobone (Pd@Au NB)-labeled electrochemical aptasensor based on PEI-g-C₃N₄/Au@Ni-CoHNB nanocomposites and a RecJf exonuclease-assisted signal amplification strategy was proposed for detection of di(2-ethylhexyl) phthalate (DEHP). Au@Ni-CoHNB/PEI-g-C₃N₄ as the electrode modification material improved the sensing performance. Pd@Au NBs carried electroactive substances as signal probes to quantify the target content precisely. In the presence of DEHP, the RecJf exonuclease assisted the target recovery to achieve signal amplification. Under the optimal conditions, the constructed aptasensor exhibited outstanding sensitivity with a low detection limit of 2.51 × 10⁻⁴ ng mL⁻¹. Furthermore, the constructed aptasensor obtained satisfactory results in terms of specificity, reproducibility, and stability, and was successfully applied in spiked liquor samples. These strategies of signal amplification employed in this work effectively improve the performance of the sensors and provide new avenues for the evolution of ultra-sensitive sensors in the field of food analysis.