title: Electrochemical aptasensor for the detection of adenosine by using PdCu@MWCNTs-supported bienzymes as labels.
abstract: A highly sensitive electrochemical adenosine aptasensor was fabricated by covalently immobilizing 3'-NH2-terminated capture probe (SSDNA1) and thionine (TH) on Au-GS modified glassy carbon electrode. 3'-SH-terminated adenosine aptamer (SSDNA2) was adsorbed onto palladium/copper alloyed supported on MWCNTs (PdCu@MWCNTs)-conjugated multiple bienzymes, glucose oxidase (GOx), and horseradish peroxidase (HRP) (SSDNA2/PdCu@MWCNTs/HRP/GOx). Then, it was immobilized onto the electrode surface through the hybridization between the adenosine aptamer and the capture probe. The signal was amplified based on the gradual electrocatalytic reduction of GOx-generated hydrogen peroxide by the multiple HRP through the mediating ability of the loaded multiple TH. However, the peak current of TH decreased in the presence of adenosine because the interaction between adenosine and its aptamer made SSDNA2/PdCu@MWCNTs/HRP/GOx release from the modified electrode. Various experimental parameters have been optimized for the detection of adenosine and tests for selectivity, reproducibility and stability have also been performed. Under the optimal condition, the proposed aptasensor displayed a wide linear range (10-400 nM) with the low detection limit (2.5 nM), which has been applied in human serum samples with satisfactory results. Thus, the combination of Au-GS as a sensor platform and PdCu@MWCNTs/HRP/GOx as labels can be a promising amplification strategy for highly sensitive adenosine detection.
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Ren
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Hu
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Fan
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China. Electronic address: sdjndxwq@163.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D000241:Adenosine / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D003300:Copper / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005949:Glucose Oxidase / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008839:Microelectrodes; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000648:ultrastructure; D010165:Palladium / Q000737:chemistry; D013194:Staining and Labeling / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; D037742:Nanotubes, Carbon; D010165:Palladium; D003300:Copper; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase; D000241:Adenosine
keywords: Adenosine; Aptamer; Electrochemical biosensor; PdCu@MWCNTs