کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5009539 | 1462048 | 2017 | 8 صفحه PDF | دانلود رایگان |
- Human chorionic gonadotropin (hCG) was detected with a peptide aptamer as the probe.
- Silver nanoparticles (AgNPs) were used as the redox reporters of the biosensor.
- The hCG-binding peptide induced the assembly and aggregation of AgNPs.
- The peptide-hCG interaction inhibited the assembly of AgNPs on electrode surface.
- The linear range was 0.001-0.2Â IU/mL and the detection limit was 0.4Â mIU/mL.
We presented an antibody-free electrochemical technique for the determination of human chorionic gonadotropin (hCG) using silver nanoparticles (AgNPs) as the redox reporters and a hCG-specific binding peptide as the receptor. Peptide-induced AgNPs assembly was achieved on the electrode surface that was modified with the same sequence of peptide (recognition element) used in the AgNPs aggregation. As a result, a well-defined linear-sweep voltammetry (LSV) peak was observed. The attachment of hCG on the electrode surface made the peptide probe lose its ability to trigger the in situ formation of the AgNPs-based network architecture on the electrode surface, thus leading to a much attenuated LSV current. The current decreased with the increase of hCG concentration ranging from 1Â mIU/mL to 0.2Â IU/mL. Consequently, a detection limit of 0.4Â mIU/mL was achieved. To demonstrate the amenability of our method, the contents of hCG in human serum/urine samples were determined. The results were consistent with those obtained by the enzyme linked immunosorbent assay (ELISA). Based on the well-defined and amplified electrochemical signal of the AgNPs-based network architecture, our work would also be valuable for the design of novel electrochemical sensors by marrying specific receptors.
Journal: Sensors and Actuators B: Chemical - Volume 243, May 2017, Pages 784-791