Dual-mode photoelectrochemical/electrochemical sensor based on Z-scheme AgBr/AgI-Ag-CNTs and aptamer structure switch for the determination of kanamycin.
Zhang LiuKeqing DengHeng ZhangChunxiang LiJinglun WangHaowen HuangQingfeng YiHu ZhouPublished in: Mikrochimica acta (2022)
A "signal-on" dual-mode aptasensor based on photoelectrochemical (PEC) and electrochemical (EC) signals was established for kanamycin (Kana) assay by using a novel Z-scheme AgBr/AgI-Ag-CNTs composite as sensing platform, an aptamer structure switch, and K 3 [Fe(CN) 6 ] as photoelectron acceptor and electrochemical signal indicator. The aptamer structure switch was designed to obtain a "signal-off" state, which included an extended Kana aptamer (APT), one immobilized probe (P1), and one blocking probe (P2) covalently linked with graphdiyne oxide (GDYO) nanosheets. P1, P2, and aptamer formed the double helix structure, which resulted in the inhibited photocurrent intensity because of the weak conductivity of double helix layer and serious electrostatic repulsion of GDYO towards K 3 [Fe(CN) 6 ]. In the presence of Kana, APT specifically bound to the target and dissociated from P1 and P2, and thus, a "signal-on" state was initiated by releasing P2-GDYO from the platform. Based on the sensing platform and the aptamer structure switch, the dual-mode aptasensor realized the linear determination ranges of 1.0 pM-2.0 μM with a detection limit (LOD) of 0.4 pM (for PEC method) and 10 pM-5.0 μM with a LOD of 5 pM (for EC method). The aptasensor displayed good application potential for Kana test in real samples.
Keyphrases
- label free
- sensitive detection
- quantum dots
- gold nanoparticles
- particulate matter
- air pollution
- visible light
- high throughput
- heavy metals
- polycyclic aromatic hydrocarbons
- molecularly imprinted
- loop mediated isothermal amplification
- magnetic nanoparticles
- ionic liquid
- lymph node metastasis
- energy transfer
- living cells
- solid phase extraction
- high resolution
- high intensity
- molecular dynamics simulations
- highly efficient
- tandem mass spectrometry
- aqueous solution
- real time pcr