• 文献标题:   Real-time detection of ochratoxin A in wine through insight of aptamer conformation in conjunction with graphene field-effect transistor
  • 文献类型:   Article
  • 作  者:   NEKRASOV N, JARIC S, KIREEV D, EMELIANOV AV, ORLOV AV, GADJANSKI I, NIKITIN PI, AKINWANDE D, BOBRINETSKIY I
  • 作者关键词:   graphene, mycotoxin, fieldeffect transistor, biosensor, aptamer, small molecule, ionic strength
  • 出版物名称:   BIOSENSORS BIOELECTRONICS
  • ISSN:   0956-5663 EI 1873-4235
  • 通讯作者地址:  
  • 被引频次:   28
  • DOI:   10.1016/j.bios.2021.113890
  • 出版年:   2022

▎ 摘  要

Mycotoxins comprise a frequent type of toxins present in food and feed. The problem of mycotoxin contamination has been recently aggravated due to the increased complexity of the farm-to-fork chains, resulting in negative effects on human and animal health and, consequently, economics. The easy-to-use, on-site, on-demand, and rapid monitoring of mycotoxins in food/feed is highly desired. In this work, we report on an advanced mycotoxin biosensor based on an array of graphene field-effect transistors integrated on a single silicon chip. A specifically designed aptamer against ochratoxin A (OTA) was used as a recognition element, where it was covalently attached to graphene surface via pyrenebutanoic acid, succinimidyl ester (PBASE) chemistry. Namely, an electric field stimulation was used to promote more efficient pi-pi stacking of PBASE to graphene. The specific G-rich aptamer strand suggest its pi-pi stacking on graphene in free-standing regime and reconfiguration in Gquadruplex during binding an OTA molecule. This realistic behavior of the aptamer is sensitive to the ionic strength of the analyte solution, demonstrating a 10-fold increase in sensitivity at low ionic strengths. The graphene-aptamer sensors reported here demonstrate fast assay with the lowest detection limit of 1.4 pM for OTA within a response time as low as 10 s, which is more than 30 times faster compared to any other reported aptamer-based methods for mycotoxin detection. The sensors hold comparable performance when operated in real-time within a complex matrix of wine without additional time-consuming pre-treatment.