title: Signal-Switchable Electrochemiluminescence System Coupled with Target Recycling Amplification Strategy for Sensitive Mercury Ion and Mucin 1 Assay.
abstract: In the present work, we first found that mercury ion (Hg(2+)) has an efficient quenching effect on the electrochemiluminescence (ECL) of N-(aminobutyl)-N-(ethylisoluminol) (ABEI). Since we were inspired by this discovery, an aptamer-based ECL sensor was fabricated based on a Hg(2+) triggered signal switch coupled with an exonuclease I (Exo I)-stimulated target recycling amplification strategy for ultrasensitive determination of Hg(2+) and mucin 1 (MUC1). Concretely, the ECL intensity of ABEI-functionalized silver nanoparticles decorated graphene oxide nanocomposite (GO-AgNPs-ABEI) was initially enhanced by ferrocene labeled ssDNA (Fc-S1) (first signal switch "on" state) in the existence of H2O2. With the aid of aptamer, assistant ssDNA (S2) and full thymine (T) bases ssDNA (S3) modified Au nanoparticles (AuNPs-S2-S3) were immobilized on the sensing surface through the hybridization reaction. Then, via the strong and stable T-Hg(2+)-T interaction, an abundance of Hg(2+) was successfully captured on the AuNPs-S2-S3 and effectively inhibited the ECL reaction of ABEI (signal switch "off" state). Finally, the signal switch "on" state was executed by utilizing MUC1 as an aptamer-specific target to bind aptamer, leading to the large decrease of the captured Hg(2+). To further improve the sensitivity of the aptasensor, Exo I was implemented to digest the binded aptamer, which resulted in the release of MUC1 for achieving target recycling with strong detectable ECL signal even in a low level of MUC1. By integrating the quenching effect of Hg(2+) to reduce the background signal and target recycling for signal amplification, this proposed ECL aptasensor was successfully used to detect Hg(2+) and MUC1 sensitively with a wide linear response.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, PR of China.
authors.forename: Xinya
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, PR of China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, PR of China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, PR of China.
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, PR of China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002413:Cations, Divalent / Q000032:analysis; D004277:DNA, Single-Stranded / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods*; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry; D018396:Mucin-1 / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D002413:Cations, Divalent; D004277:DNA, Single-Stranded; C060192:MUC1 protein, human; D018396:Mucin-1; D006046:Gold; D008628:Mercury