It
is of great significance for the analysis of multiple biomarkers
because a single biomarker is difficult to accurately achieve early
diagnosis, disease course monitoring, and prognosis evaluation. Herein,
a luminescence thermosensitive hydrogel was synthesized by radical
polymerization using a methacrylic acid derivative monomer of luminol
(LuMA) as luminescent, N-isopropylacrylamide (NIPAM)
as thermosensitive monomer, and acrydite-oligonucleotides [dopamine
(DA) aptamer, DNA C1, and DNA C2] as recognition elements. The combined
DA based on the affinity interaction between the DA and the aptamer
on the hydrogel polymer chain was electrochemically oxidized to dopamine
quinone during the electrochemiluminescence (ECL) scanning, which
effectively quenched the ECL signal of LuMA due to the resonance energy
transfer (RET). In addition, the thermosensitive hydrogel showed swelling-collapse
characteristics when the temperature was below and above the volume
phase transition temperature. Undergoing the collapse process initiated
by the temperature, the RET efficiency was further enhanced due to
the shortened distance between the energy donor and acceptor, showing
a 1.4 times signal amplification and achieving sensitive detection
of DA with a limit of detection (LOD) of 1.7 × 10–10 M. For a proof of concept application, coupled with the target-induced
release of DA from the DNA-magnetic beads bioconjugations based on
duplex-specific nuclease (DSN)-assisted target recycling amplification
strategy and DNAzyme cleavage reaction, this ECL-RET approach was
successfully used to evaluate multiple targets including miRNA-141
and MUC1 with the LOD of 2.5 aM and 1.6 fg/mL, respectively. The excellent
performances of the versatile and robust ECL-RET hydrogel in multiple
target sensing showed potential applications in clinical diagnosis
and disease therapeutic assay.