Details

Autor(en) / Beteiligte

• Tang, Juan
• Xiong, Pengyuan
• Li, Jingjing
• Cheng, Yu
• Tian, XiaoChun
• Chen, Ya
• Sun, Yuanfang
• Tang, Dianping

Titel

Target-induced elimination of photosensitizer and formation insulation layer enabling ultrasensitive photoelectrochemical detection of ochratoxin A

Ist Teil von

• Sensors and actuators. B, Chemical, 2019-10, Vol.297, p.126707, Article 126707

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •GO-CdS-MoS2-AuNPs heterostructure exhibited superior PEC performance attributed to the stepwise band-edge levels.•The photocurrent response could be highly enhanced after porphyrin (as photosensitizer) intercalated into dsDNA strands.•In the presence of target, photosensitizer was eliminated from the platform and SiO2@hDNA as formation insulation layer was assembled.•The work provided a new paradigm for designing photoelectrochemical detection mode based on multiple signal amplified strategy. An efficient photoelectrochemical aptasensor with triple signal amplification was developed for sensitive determination of ochratoxin A (OTA). Briefly, gold nanoparticles were decorated onto the GO-CdS-MoS2 nanocomposites to form GO-CdS-MoS2-AuNPs nanostructure, which was utilized as the photoelectrochemical matrix to immobilize the auxiliary DNA (aDNA) for the following hybridization with the complementary OTA aptamer (OTA Apt). Then, porphyrin (TMPyP) molecules employed as an efficient photosensitizer can be intercalated into double-stranded DNA (dsDNA). Thus, an enhanced initial PEC signal was acquired. Upon introduction of OTA, the aptamer-OTA complex was formed and detached from the electrode, while the TMPyP molecules releasing from the platform. The photocurrent signal was highly decreased ascribed to the target induced elimination of photosensitizer. Then, the SiO2@helpDNA (SiO2@hDNA) can be assembled on the electrode through the re-exposed aDNA. Notably, the steric hindrance of the SiO2 and hDNA may effectively depress the electron transfer, thus obviously enlarge the decrement of the photocurrent responses. Under optimized condition, the program shows satisfied analytical performance for OTA with a low detection limit of 0.00021 ng mL−1. Meanwhile, it also presents outstanding reproducibility, stability and specificity. Importantly, the sensing platform provides a new ideal for detection of toxins.