Charge effect-based aptamer sensor, and construction method and application thereof

Abstract

The invention discloses a charge effect-based aptamer sensor, and a construction method and an application thereof. The construction method of the sensor comprises the following steps: immersing a gold electrode in a tetrahydrofuran solution containing 4-[(trimethylsilyl)ethynyl]benzoic acid and tetrabutylammonium fluoride, and carrying out a reaction in a room temperature environment to obtain a 4-carboxylphenylethynyl modified gold electrode; carrying out a hybridization reaction on DNA1 and DNA2 to obtain dsDNA; and carrying out an amidation reaction on the 4-carboxylphenylethynyl modified gold electrode and the dsDNA, and adding a compound containing nanogold-streptavidin, ferrocenylalkanethiol and a tumor marker aptamer to obtain the aptamer sensor having the advantages of low cost, good stability, simplicity in detection, high sensitivity and high specificity.

Description

technical field [0001] The invention relates to a biosensor, in particular to an aptamer sensor based on a charge effect and a construction method thereof, as well as an electrochemical method for detecting tumor markers by using the sensing, and belongs to the field of electrochemical biosensors. Background technique [0002] Alzheimer's disease (AD) is a progressive and fatal neuromutation disease. There is no definitive diagnostic test in routine clinical practice. Markers of AD brain include plaques composed of extracellular β-amyloid (Aβ) protein aggregates and intracellular hyperphosphorylated tau neurofibrillary tangles. The current research on amyloid Aβ affecting AD shows that the aggregation process of Aβ is roughly the aggregation process of Aβ from monomer to oligomer to fiber. Compared with amyloid fibrils, soluble amyloid oligomers are the most cytotoxic aggregates, and the content in the cerebrospinal fluid of patients with Alzheimer's disease is significant...

AI Technical Summary

Problems solved by technology

The existing fluorescence and SPR methods for detecting Aβ have their advantages and disadvantages. Effectiveness, ease of operation, and no radiation are common advantages. However, Aβ species are usually Aβ monomers, Aβ oligomers, and Aβ aggregates. If the detection method cannot accurately identify Aβ oligomers, it will reduce its sensitivity

For the traditional electrochemical method, the typical method is to use mercapto groups to combine with gold electrodes and fix them on the electrode surface. This method is unstable and easy to fall off during electrochemical testing, and the molecular cost of modifying mercapto groups is relatively high.

Therefore, rapid, sensitive, and low-cost detection of Aβ oligomers remains a great challenge

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