Yawen Zhu,Xuemei Wang,Zhiyong Yan,Feifei Zhang,Jianfei Xia,Lili Lv,Zonghua Wang
The dual-signal output self-calibration mode reduces the false positive and negative signals of electrochemiluminescence (ECL) aptamer sensors. A competitive dual-signal ECL platform was designed for the ultrasensitive detection of kanamycin (KAN) using a zirconium metal–organic framework (Zr MOF) and Luminol as ECL emitters. To enhance the ECL efficiency, a co-reactant (polyethyleneimine, PEI) was covalently bound to the Zr MOF to achieve self-enhanced ECL. Based on the selective interaction between KAN and its aptamer, the Luminol/KAN/Zr MOF-PEI “sandwich” structure was immobilized on the electrode surface. The competition for PEI between emitters increased the Luminol ECL signal and decreased the Zr MOF’s ECL signal. The ratio in ECL signals between the two competitive emitters enabled the quantitative analysis of KAN, achieving a detection limit as low as 7.86 × 10−4ng/mL. This study elucidated the synergistic mechanism between self-enhanced ECL and ECL competition, offering a novel approach for constructing dual-signal ECL sensors using a single co-reactant.
Exploring novel and sensitive analysis methods for monitoring lincomycin (Lin) residues is of great significance since overuse of it would cause a serious threat to public health. Herein, a Zr-porphyrin metal-organic frameworks (Zr-TCPP) with covalently modified polyamidoamine (PAMAM) dendrimers was synthesized as a novel intramolecular self-enhanced ECL reagent, which exhibited greatly improved ECL response due to the promotion of SO 4 •– generation and the shortening of the electron transfer distance. Graphene oxide modified with gold nanoparticles (Au@GO) was synthesized as the quencher for the ECL sensor construction based on the quenching strategy. The present aptasensor achieved a wide linear range of 1.0 × 10 −14 − 5.0 × 10 −9 g/mL and a low detection limit of 1.7 fg/mL, which was applied for the determination of Lin in different real samples with satisfactory results.
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