An amplified photoelectrochemical aptasensor based on Bi2S3/BiFeO3 for ochratoxin A detection

• Published in: Talanta (Oxford) 2023-02, Vol.253, p.123988, Article 123988
• Main Authors: Wang, Lu-Ying, Chen, Jing-Shuai, Liu, Xing-Pei, Mao, Chang-Jie, Jin, Bao- Kang
• Format: Article
• Language: English
• Subjects: BiFeO3/Bi2S3; Methylene blue; Ochratoxin A; Photoelectrochemicial aptasensor
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2022.123988

In this paper, an ultrasensitive photoelectrochemical aptasensor based on amplified signal strategy and competitive mechanism for ochratoxin A (OTA) detection was developed. The prepared photoactive composite material (BiFeO3/Bi2S3) possessed excellent separation ability of photognerated electron-hole pair and effectively inhibited the recombination of hole and pair, resulting in significantly enhanced photocurrent intensity. The amplified signal strategy was achieved by adding methylene blue (MB), which facilitated electron transfer and improved the photoelectric conversion efficiency. In the presence of OTA, the aptamer can be recognized and captured, the complementary DNA (cDNA) and MB were released from the aptasensor electrode, a decreased photocurrent signal appeared, thus achieving quantitative detection for OTA. Under optimal conditions, the aptasensor exhibited a wide linear relationship range from 10−5 to 10−13 g/mL and a low detection limit of 0.0135 fg/mL (3σ/S). Simultaneously, the proposed photoelectrochemical aptasensor also showed excellent accuracy, stability, precision and selectivity. Schematic showing the steps involved in fabrication of the photoelectrochemical biosensor. [Display omitted] •The signal amplified photoelectrochemical aptasensor was established for the detection of ochratoxin A (OTA).•The photocurrent of composite material was 1.5 and 160 fold of pure Bi2S3 and BiFeO3 respectively.•Methylene blue (MB) was used as sensitizer to amplify the detection signal.•The proposed photoelectrochemical aptasensor presented wide detection range and ultra-low detection limit for OTA.