Potentiometric aptasensing of small molecules based on surface charge change
Abstract Solid-state potentiometric sensors based on surface charge change are well-established tools for measuring ions and biological species. However, their use for detection of small molecules with high sensitivity and good selectivity is still elusive. In this work, a novel potentiometric aptasensing platform for small molecules is presented, using bisphenol A (BPA) as a model. The proposed sensor can be prepared by layer-by-layer assembling of carboxylated multiwall carbon nanotubes, poly(diallyldimethylammonium chloride) (polycation), and aptamer (polyanion) on the electrode surface. The presence of BPA induces the conformational change and detachment of the aptamer at the surface of the modified electrode, which leads to a variation of the surface charge (negative to positive) and therefore a potential change. The introduction of polyions can cause substantial charge change on the electrode surface, thus improving the sensitivity of the sensor. The morphology and electron-transfer properties of the electrode have been characterized. Under optimum conditions, the present sensor shows a stable response to BPA in the concentration range from 3.2 × 10 −8 to 1.0 × 10 −6 M with a detection limit of 1.0 × 10 −8 M. The proposed methodology can be used for sensitive potentiometric sensing of other small molecules involved in aptamer/target binding events. Highlights A potentiometric aptasensor with improved sensitivity is described. The sensing film can be prepared via a layer-by-layer assembly process. The introduction of polyions leads to an enhancement of sensitivity. The aptamer/target binding causes surface charge change. Graphical abstract A potentiometric aptasensing platform for small molecules with improved sensitivity is presented. Bisphenol A (BPA), as a small molecule was selected as a model. [DISPLAY OMISSION]
유료 다운로드의 경우 해당 사이트의 정책에 따라 신규 회원가입, 로그인, 유료 구매 등이 필요할 수 있습니다. 해당 사이트에서 발생하는 귀하의 모든 정보활동은 NDSL의 서비스 정책과 무관합니다.
원문복사신청을 하시면, 일부 해외 인쇄학술지의 경우 외국학술지지원센터(FRIC)에서
무료 원문복사 서비스를 제공합니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 위의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.
- 이 논문과 함께 출판된 논문 + 더보기