Search

A novel CdTe quantum dots - single walled carbon nanohorns (CdTe-SWCNHs) nanocomposite was synthesized via a one-pot method for photoelectrochemical (PEC) aptasensing detection of streptomycin (STR). The CdTe-SWCNHs nanocomposite shows 3.2-times amplified PEC activity in comparison with CdTe quantum dots (QDs). By using aptamers as recognition element and CdTe-SWCNHs as photoactive species, a PEC aptasensor was fabricated for the high sensitive and selective detection of STR. Under the optimized conditions, the as-fabricated PEC aptamer sensor exhibits a linear response ranging from 0.1 nM (0.15 μg kg −1 ) to 50 nM (72.85 μg kg −1 ) with a detection limit ( S / N = 3) of 0.033 nM (0.05 μg kg −1 ). The aptasensor has successfully applied for the determination of streptomycin in honey sample, which provides a new method for detection of streptomycin. [ABSTRACT FROM AUTHOR]

• A direct Z-scheme CdTe/APTES-WO 3 heterostructure was synthesized by electrostatic adsorption. • The resultant CdTe/APTES-WO 3 /ITO exhibited a 2.5-fold higher photocurrent than that at CdTe/ITO. • The proposed PEC aptasensor showed superior analytical properties for STR. The newly-emerging direct Z-scheme heterostructures have been extensively studied as photocatalysts; however, their photoelectrochemical (PEC) aptasensing applications are still in infancy. In this work, we constructed a novel direct Z-scheme heterostructure with CdTe quantum dots (QDs) and WO 3 nanosheets via interface engineering for PEC aptasensing of streptomycin (STR). To fabricate the solid-solid interface with a large effective area, the surface modification of WO 3 by (3-Aminopropyl) triethoxysaline (APTES) was performed to uniformly absorb negatively-charged CdTe QDs via electrostatic interaction. The resultant CdTe/APTES-WO 3 heterostructure showed a 2.5-times amplified PEC response compared with that of CdTe QDs. The photoinduced Z-Scheme electron transfer mechanism was confirmed in such heterostructure. Taking advantage of its superior PEC properties, a high-performance aptasensor for the detection of STR was constructed. The proposed aptasensor showed a linear response ranging from 1.0 × 10−9 M (1.5 μg kg−1) to 5.0 × 10−7 M (728.5 μg kg−1) with a detection limit (S/N = 3) of 3.3 × 10−10 M (0.5 μg kg−1). Moreover, the aptasensor has been applied to STR analysis in leaves of pimiento. Our work provided a novel and efficient strategy for the detection of STR, which should also promote the application of PEC aptasensing in agricultural field. [ABSTRACT FROM AUTHOR]