A Highly Sensitive Electrochemical Aptasensor for Kanamycin:Leveraging RecJf Exonuclease-Assisted Target Recycling and Hybridization Chain Reaction Signal Amplification  

作　　者：Qi Xiao Dongyou Zhang Mingli Yang Shuai Liu Yi Fang Shan Huang 

机构地区：[1]Guangxi Key Laboratory of Natural Polymer Chemistry and Physics,College of Chemistry and Materials,Nanning Normal University,Nanning 530001,China

出　　处：《Journal of Analysis and Testing》2025年第1期96-108,共13页分析检测(英文)

基　　金：financially supported by Central Government Guided Local Science and Technology Development Fund Project(guikeZY22096017);Natural Science Foundation of Guangxi Province(2024GXNSFDA010036);National Natural Science Foundation of China(22164014,U23A2089)。

摘　　要：A highly sensitive electrochemical aptasensor was developed for the detection of kanamycin,employing a DNA signal amplification strategy that combines RecJf exonuclease-assisted target recycling with a hybridization chain reaction(HCR).The sensing platform is constructed by covalently immobilizing double-stranded DNA(dsDNA)comprised of a kanamycin-specific aptamer and its thiol-modified complementary strand(SH-CDNA)onto a gold electrode.In the presence of kanamycin and RecJf exonuclease,the aptamer selectively binds to kanamycin,dissociating from the dsDNA complex.The RecJf exonuclease then cleaves the aptamer,releasing kanamycin and initiating a cycle of repetitive binding and release.The residual SH-CDNA on the electrode triggers an HCR between two types of ferrocene-labeled hairpin DNA,forming an elongated stable dsDNA nanostructure.This results in an amplified electrochemical signal proportional to the logarithm of kanamycin concentration over a range of 0.01–10 nmol/L,with a remarkable detection limit of 1.8 pmol/L.The aptasensor's performance was validated by analyzing spiked kanamycin in pharmaceutical eye drops and milk samples,yielding recovery rates between 95.6%and 104.8%and relative standard deviations from 1.4%to 4.2%.With its exceptional selectivity and sensitivity,this aptasensor offers a compelling alternative to traditional HPLC for rapid on-site detection of kanamycin.Capitalizing on the specificity of aptamers,the sensor design presented herein serves as a valuable blueprint for engineering detectors of other molecules,with significant implications for analytical chemistry and food safety monitoring.

关 键 词：KANAMYCIN Target recycling Hybridization chain reaction Signal amplification Long dsDNA nanostructures 

分 类 号：O657.1[理学—分析化学] TP212[理学—化学] TS207.3[自动化与计算机技术—检测技术与自动化装置]