A novel signal amplification strategy of an electrochemical aptasensor for kanamycin, based on thionine functionalized graphene and hierarchical nanoporous PtCu

• Published in: Biosensors & bioelectronics 2016-03, Vol.77, p.752-758
• Main Authors: Qin, Xiaoli, Yin, Yan, Yu, Huijing, Guo, Wenjuan, Pei, Meishan
• Format: Article
• Language: English
• Subjects: Alloys - chemistry; Amplification; Anti-Bacterial Agents - analysis; Aptamers, Nucleotide - chemistry; Biosensors; Conductometry - instrumentation; Copper - chemistry; Electrochemical aptasensor; Equipment Design; Equipment Failure Analysis; Food Analysis - instrumentation; Food Contamination - analysis; Graphene; Graphite - chemistry; Kanamycin; Kanamycin - analysis; Linearity; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Nanopores - ultrastructure; Nanostructure; Phenothiazines - chemistry; Platinum; Platinum - chemistry; Reduction; Reproducibility of Results; Sensitivity and Specificity; Specific surface; Strategy; Thionine
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2015.10.050

An ultrasensitive electrochemical aptasensor for the quantitative detection of kanamycin antibiotic was fabricated based on a novel signal amplification strategy. This aptasensor was developed using thionine functionalized graphene (GR-TH) and hierarchical nanoporous (HNP) PtCu alloy as biosensing substrates for the first time. HNP-PtCu alloy with controllable bimodal ligament/pore distributions was successfully prepared by two-step dealloying of a well-designed PtCuAl precursor alloy combined with an annealing operation. GR-TH composite was synthesized by one-step reduction of graphene oxide (GO) in TH solution. Greatly amplified sensitivity was achieved by using GR-TH/HNP-PtCu composite owing to its large specific surface and good electron-transfer ability. Under the optimized conditions, the proposed aptasensor exhibited a high sensitivity and a wider linearity to kanamycin in the range 5×10−7–5×10−2μgmL−1 with a low detection limit of 0.42pgmL−1. This aptasensor also displayed a satisfying electrochemical performance with good stability, selectivity and reproducibility. The as-prepared aptasensor was successfully used for the determination of kanamycin in animal derived food. •An ultrasensitive electrochemical aptasensor adopting a novel signal amplification strategy was developed for kanamycin detection.•A low detection limit of 0.42pgmL−1 and a wide linear range of 5×10−7–5×10−2μgmL−1 were obtained.•The prepared aptasensor shows high sensitivity, reproducibility and stability.