A Host–Guest Interaction-Based and Metal–Organic Gel-Based Biosensor with Aggregation-Induced Electrochemiluminescence Enhancement for Methyltransferase Assay

Abstract

Metal−organic gels (MOGs) are new soft materials with the characteristics of high colloidal stability, superb luminescence properties, and facile synthesis. Herein, we develop for the first time a host−guest interaction-based and MOG-based biosensor with aggregation-induced electrochemiluminescence (ECL) enhancement for M.SssI methyltransferase (M.SssI MTase) assay. This biosensor employs a MOG as the luminophor and potassium persulfate as the coreactant, and the formation of the Ag-MOG from the aggregation of silver nanoclusters can induce significant ECL enhancement. Two complementary single-stranded DNAs (ssDNAs, i.e., biotinylated DNA-1 and Fc-labeled DNA-2) that contain specific recognition sequence 5′-CCGG-3′ can form a double-stranded DNA (dsDNA) probe. In the absence of M.SssI MTase, the dsDNA probe will be digested by restriction endonuclease HpaII, leading to the release of Fc from magnetic beads (MBs). The β-CD can specifically recognize the released Fc through guest−host interaction, resulting in the quenching of an ECL signal. In contrast, the presence of M.SssI MTase enables the formation of fully methylated dsDNA, which cannot be cleaved by HpaII, making Fc remain on the MB surface and consequently generating an improved ECL signal. This biosensor can specifically detect M.SssI MTase with a linear range of 0.05−100 U mL −1 and a limit of detection of 3.5 × 10 −3 U mL −1 , and it enables accurate detection of M.SssI MTase in human serum. In addition, it can be used for inhibitor screening, with wide applications in drug discovery and disease diagnosis.

Aggregation-induced delayed fluorescence luminogens: the innovation of purely organic emitters for aqueous electrochemiluminescence

“…13,25 Meanwhile, ECL bioscience sensing studies using these emitters have also been developed, e.g. chloramphenicol sensor 26 , methyltransferase assay 27 , microRNA assay 28 etc. However, a main challenge of the AIECL motif is the low ECL efficiency.…”

Bipolar Aggregation-Induced Electrochemiluminescence of Thiophene-Fused Conjugated Microporous Polymers

“…ECL combines the advantages of luminescent and electrochemical techniques, , and it is superior to photoluminescence in many respects including high sensitivity and the elimination of scattered light/auto-fluorescence backgrounds . The combination of ECL and AIE may induce an enhanced ECL signal, triggering the research for the discovery of luminescent molecules with aggregation-induced ECL (AIECL) properties . Different from other monomers whose aggregation may cause quenching, the aggregation of tetraphenylethylene (TPE) induces emission .…”

High Sensitive Electrochemiluminescence Biosensor Based on Ru(phen)32+‐loaded Double Strand DNA as Signal Tags use to Detect DNA Methyltransferase Activity

“…DNA MTase plays an important role in the organism, and high‐sensitivity detection of its activity may provide clinicians with useful information such as early diagnosis and disease staging [10–12]. Many methods, include colorimetry [13, 14], fluorescence [15, 16], electrochemistry [17, 18], electrochemiluminescence [19, 20], etc. had been developed for DNA MTase activity detection.…”