کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5031308 | 1470933 | 2018 | 6 صفحه PDF | دانلود رایگان |
- Pb2+dependent DNAzyme electrochemical biosensor for carcinoembryonic antigen detection was developed.
- The graphene quantum dots-ionic liquid-nafion composite film was fabricated on electrode for the first time.
- The target-aptamer complex recycling led to continuous cleavage of substrate chain and amplified electrochemical signal.
- The method has been applied in human serum, with high selectivity and good recovery.
In this work, we have developed an electrochemical aptasensor for high-sensitivity determination of carcinoembryonic antigen (CEA) based on lead ion (Pb2+)-dependent DNAzyme-assisted signal amplification and graphene quantum dot-ionic liquid-nafion (GQDs-IL-NF) composite film. We designed hairpin DNA containing CEA-specific aptamers and DNAzyme chains. In the presence of CEA, hairpin DNA recognized the target and performed a DNAzyme-assisted signal amplification reaction to yield a large number of single-stranded DNA. The GQDs-IL-NF composite film was immobilized on the glassy carbon electrode for the interaction with single-stranded DNA through noncovalent Ï-Ï stacking interaction. Therefore, the methylene blue-labeled substrate DNA (MB-substrate) was fixed on the electrode and exhibited an initial electrochemical signal. Under optimal conditions, the response current change was proportional to the concentration of CEA, demonstrating a wide linear range from 0.5 fg mLâ1 to 0.5 ng mLâ1, with a low detection limit of 0.34 fg mLâ1. Furthermore, the proposed aptasensor was successfully applied in determining CEA in serum samples, showing its superior prospects in clinical diagnosis.
Journal: Biosensors and Bioelectronics - Volume 99, 15 January 2018, Pages 28-33