posted on 2024-02-16, 10:33authored byZihua Guo, Bin Yang, Weiyi Lu, Zhen Tian, Huimin Hao
Chemiluminescence is a powerful analytical technique
with many
advantages, while aptamers are well-known as good molecular recognition
units. However, many aptamer-based chemiluminescence assays employed
interface sensing, which often needed several immobilization, separation,
and washing steps. To minimize the risks of contamination and false-positive,
we for the first time proposed a photocatalytic aptamer chemiluminescent
system for a homogeneous, label-free, generic assay of small molecules.
After binding to a DNA aptamer, thioflavin T has a unique photocatalytic
oxidase activity to activate the system’s luminol chemiluminescence.
Then, the specific binding between the aptamer and target molecules
will compete with the above process. Therefore, we can realize the
efficient assay of different analytes including estradiol and adenosine.
Such a homogeneous chemiluminescent system allowed a direct assay
of small molecules with limits of detection in a nM level. Several
control tests were carried out to avoid possible false-positive results,
which were originated from the interactions between analytes and sensing
interfaces previously. This homogeneous chemiluminescent system provides
a useful strategy to reliably assay various analytes in the pharmacy
or biology field.