TY  - JOUR
AU  - Zhang, Yuting
AU  - Figueroa-Miranda, Gabriela
AU  - Zafiu, Christian
AU  - Willbold, Dieter
AU  - Offenhäusser, Andreas
AU  - Mayer, Dirk
TI  - Amperometric Aptasensor for Amyloid-β Oligomer Detection by Optimized Stem-Loop Structures with an Adjustable Detection Range
JO  - ACS sensors
VL  - 4
IS  - 11
SN  - 2379-3694
CY  - Washington, DC
PB  - ACS Publications
M1  - FZJ-2020-00227
SP  - 3042 - 3050
PY  - 2019
AB  - Amyloid-β oligomers (AβO) have become representative biomarkers for early diagnosis of Alzheimer's disease. Here, we report on an aptasensor based on stem-loop probes for sensitive and specific detection of AβO by an amperometric transducer principle using alternating current voltammetry (ACV). Stem-loop probes with redox-active moieties are immobilized on a gold substrate as a receptor element. The signal transduction mechanism relies on redox ferrocene (Fc) reporting via charge transfer on a molecular recognition event involving a conformational change of the molecular beacon. The stem-loop structures were optimized by considering the aptamers' stem length, spacer, and different ferrocene terminals. In addition, the sensor assembly and signal recording including aptamer concentration and ACV frequency dependence are discussed. Using the optimized stem-loop probe (B-3' Fc), the aptasensor showed a decrease of the Fc peak current induced by AβO binding within the broad concentration range spanning 6 orders of magnitude. Furthermore, the detection limit of the sensor can be further decreased by optimizing the ACV frequency, however at the cost of a narrowed detection range. In this work, a label-free electrochemical aptasensor is demonstrated, which facilitates the quantification of the concentration of AβO with high selectivity and subpicomolar sensitivity, which may be conducive to improving the diagnosis and pharmacology studies of Alzheimer's disease.
LB  - PUB:(DE-HGF)16
C6  - pmid:31674772
UR  - <Go to ISI:>//WOS:000499737100028
DO  - DOI:10.1021/acssensors.9b01630
UR  - https://juser.fz-juelich.de/record/872749
ER  -