title: An electronic channel switching-based aptasensor for ultrasensitive protein detection.
abstract: Due to the ubiquity and essential of the proteins in all living organisms, the identification and quantification of disease-specific proteins are particularly important. Because the conformational change of aptamer upon its target or probe/target/probe sandwich often is the primary prerequisite for the design of an electrochemical aptameric assay system, it is extremely difficult to construct the electrochemical aptasensor for protein assay because the corresponding aptamers cannot often meet the requirement. To circumvent the obstacles mentioned, an electronic channel switching-based (ECS) aptasensor for ultrasensitive protein detection is developed. The essential achievement made is that an innovative sensing concept is proposed: the hairpin structure of aptamer is designed to pull electroactive species toward electrode surface and makes the surface-immobilized IgE serve as a barrier that separates enzyme from its substrate. It seemingly ensures that the ECS aptasensor exhibits most excellent assay features, such as, a detection limit of 4.44×10(-6)μg mL(-1) (22.7fM, 220zmol in 10-μL sample) (demonstrating a 5 orders of magnitude improvement in detection sensitivity compared with classical electronic aptasensors) and dynamic response range from 4.44×10(-6) to 4.44×10(-1)μg mL(-1). We believe that the described sensing concept here might open a new avenue for the detection of proteins and other biomacromolecules.
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Li
authors.forename: Cui
authors.initials: C
authors.lastname: Wang
authors.forename: Zaisheng
authors.initials: Z
authors.lastname: Wu
authors.forename: Limin
authors.initials: L
authors.lastname: Lu
authors.forename: Liping
authors.initials: L
authors.lastname: Qiu
authors.forename: Hui
authors.initials: H
authors.lastname: Zhou
authors.forename: Guoli
authors.initials: G
authors.lastname: Shen
authors.forename: Ruqin
authors.initials: R
authors.lastname: Yu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis*; D057230:Limit of Detection; D009690:Nucleic Acid Conformation
chemical_list: D052157:Aptamers, Nucleotide; D007073:Immunoglobulin E