Photoelectrochemical aptasensing of ofloxacin based on the use of a TiO2 nanotube array co-sensitized with a nanocomposite prepared from polydopamine and Ag2S nanoparticles
A photoelectrochemical (PEC) method is described for aptamer-based detection of ofloxacin (OFL). It is making use of a TiO2 nanotube array (NTA) that is sensitized with a structure composed of polydopamine and silver sulfide nanoparticles. The NTA were prepared by a two-step synthetic method. First, the TiO2 nanotube electrode was covered with Ag2S nanoparticles via successive ionic layer adsorption and reaction strategy. Next, they were coated with a thin film of polydopamine (PDA) by in-situ polymerization. The inorganic/organic nanocomposites exhibit distinctly enhanced visible-light PEC activity. This was exploited to fabricate a PEC aptasensor. The PDA film serves as both the sensitizer for charge separation and as a support to bind the aptamer against OFL. The aptasensor undergoes a decrease in photocurrent due to the formation of the aptamer-OFL complex. Under the optimized conditions and at a typical working potential of 0 V (vs. Hg/Hg2Cl2), the NTA has a linear response in the 5.0 pM to 100 nM OFL concentration range and a 0.75 pM detection limit (at S/N = 3). The aptasensor was successfully applied to the determination of OFL in spiked milk samples.
KeywordsInorganic/organic nanocomposite Sensitization Aptasensor Antibiotic detection Food sample
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The author(s) declare that they have no competing interests.
- 30.Mirzajani R, Pourreza N, Burromandpiroze J (2018) Fabrication of magnetic Fe3O4@nSiO2@mSiO2–NH2 core–shell mesoporous nanocomposite and its application for highly efficient ultrasound assisted dispersive μSPE-spectrofluorimetric detection of ofloxacin in urine and plasma samples. Ultrason Sonochem 40:101–112CrossRefGoogle Scholar
- 33.Dai J, Shi C, Li C, Shen X, Peng L, Wu D, Sun D, Zhang P, Zhao J (2016) A rational design of separator with substantially enhanced thermal features for lithium-ion batteries by the polydopamine-ceramic composite modification of polyolefin membranes. Energy Environ Sci 9:3252–3261CrossRefGoogle Scholar