Jingwen Gao,Huiwen Xiong,Wei Zhang,Ying Wang,Hangxing Wang,Wei Wen,Xiuhua Zhang,Shengfu Wang
Here, an electrochemiluminescent aptasensor based on β-cyclodextrin/graphitic carbon nitride (β-CD/g-C 3 N 4 ) composite for selective and highly ultrasensitive assay of platelet derived growth factor BB (PDGF-BB) is fabricated. To achieve the sensitive and specific detection of PDGF-BB, it is an available strategy to explore excellent electrochemiluminescent (ECL) luminophores with the advantages of high electrochemical-driven luminescent activity and a specific recognition function. In this work, for the first time a novel β-CD non-covalently functionalized g-C 3 N 4 composite β-CD/g-C 3 N 4 was employed to construct the ECL detection platform for PDGF-BB based on its aptamer. The limit of detection was determined to be as low as 2.6 × 10 −13 g/mL. It was observed that β-CD was playing a key role in improving the adamantane-labeled DNA amount modified on the electrode surface. It can further help to amplify the ECL quenching effect by both energy transfer and photo-excited electron transfer processes between g-C 3 N 4 emitter and ferrocene quencher. It is anticipated that β-CD/g-C 3 N 4 may be a class of promising material for constructing ECL sensors.
Qingqing Zhang,Dandan Hu,Tianyu Zhan,Yufang Hu,Zhiyong Guo,Sui Wang
A novel Medusa electrochemiluminescence (ECL) immunosensor for quantitative detection of histone acetyltransferase (HAT p300) is designed and built well based on magnetic gold nanoparticles (Au-Fe 3 O 4 NPs), DNA nanonets and terminal deoxynucleotidyl transferase (TdT)-triggered renascent DNAs containing abundant A and T (named as AT-dsDNAs). Firstly, Au-Fe 3 O 4 NPs and substrate peptides are coated with the bare electrode surface one after the other. As the acetylation reaction happens, DNA nanonets, which are synthesized via Y-shape DNA (as building block) and acetyl antibody (Ab Ac )-grafted dsDNA (as crosslinker), are attached on the electrode surface. Next, AT-dsDNAs are formed under NaCl condition by TdT catalysis, in where deoxyadenosine triphosphate (dATP) and deoxythymidine triphosphate (dTTP) (half and half) can be added ceaselessly to countless 3′−OH of DNA nanonets. Abundant Ru(phen) 3 2+ molecules, which can be integrated well into high-level DNA nanomaterials above, serve as ECL luminophore in our biosensing. Only being HAT p300, an outstanding ECL response occurs favorably, and a detection limit of 0.0029 nM is acquired with a linear response in the range of 0.006–60 nM. The Medusa immunosensor with improved sensitivity presents a promising and possible widely use for the HATs-relevant clinical study and drug development.
Jiu-Jun Yang,Jun-Tao Cao,Yu-Ling Wang,Hui Wang,Yan-Ming Liu,Shu-Hui Ma
A new and simple sandwich-like electrochemiluminescence (ECL) aptasensor for carcinoembryonic antigen (CEA) assay was fabricated based on the dual quenching effect from hemin-graphene (H-rGO) nanosheet and enzymatic biocatalytic precipitation (BCP) on the Au-CdS nanocomposites-based ECL system. In this aptasensor platform, flower-like spherical Au-CdS nanocomposites were used as ECL luminophores and exhibit a strong ECL signal. The rGO nanosheet was used as a supporter to immobilize hemin molecules via π-π stacking interactions. Due to the steric hindrance and quenching effect of rGO, the ECL intensity decreased by the construction of the sandwich “CEA aptamer I (NH 2 -DNA)-CEA-aptamer II” (H-rGO-aptamer II) mode. In the process of BCP, the ECL intensity further decreased because the hemin with intrinsic peroxidase-like catalytic activity could oxidize the 4-chloro-1-naphthol (4-CN) to produce an insoluble precipitation on the sensor. Using this dual quenching strategy, the prepared aptasensor exhibits a linear range from 0.8 pg/mL to 4 ng/mL and a detection limit of 0.28 pg/mL. This ECL aptasensor has simple design and undemanding in operation and was utilized to determine the content of CEA in complex samples with recoveries of 95.0% to 115.8%. Moreover, no any chemical modification of aptamer was required, suggesting that the proposed ECL aptasensor could be applied for the detection of diverse proteins just by altering the aptamer sequence.
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