Preparation and application method of electrochemical reduction graphene oxide and nanogold modified electrode based DNA sensor

A technology for modifying electrodes and graphene. It is applied to electrochemical variables of materials, instruments, scientific instruments, etc. It can solve problems such as affecting the sensitivity of electrochemical sensors, and achieve the effect of easy surface, convenient use and good conductivity.

Inactive Publication Date: 2016-07-13
QINGDAO UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The most critical is the immobilization of the probe ssDNA and the electrochemical detection of the hybridization reaction. The immobilization amount of the probe ssDNA on the electrode surface and the detection method of the hybridization reaction will affect the sensitivity of the electrochemical sensor.

Method used

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  • Preparation and application method of electrochemical reduction graphene oxide and nanogold modified electrode based DNA sensor
  • Preparation and application method of electrochemical reduction graphene oxide and nanogold modified electrode based DNA sensor
  • Preparation and application method of electrochemical reduction graphene oxide and nanogold modified electrode based DNA sensor

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Experimental program
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Embodiment 1

[0033] The preparation method of embodiment 1 DNA sensor

[0034] (1) Accurately weigh 1.6g of graphite powder and 0.8g of HPPF with an electronic balance 6 , the weighed graphite powder and HPPF 6 Put it in an agate mortar and grind it evenly to get the ionic liquid modified carbon paste, then slowly fill the ionic liquid modified carbon paste into a glass tube with a length of 6cm and an inner diameter of 4mm for compaction, and insert a thin copper wire as a wire , to obtain the ionic liquid modified carbon paste electrode (CILE), which was polished to a mirror surface on a clean polishing paper before use.

[0035] (2) Accurately weigh a certain mass of HAuCl with an electronic balance 4 with NaNO 3 , dissolved in 50ml double-distilled water, ultrasonically dispersed evenly, that is, 3.0mmol / LHAuCl 4 and 0.1mol / L NaNO 3 mixture. With CILE as the working electrode, platinum as the auxiliary electrode, and a saturated calomel electrode as the reference electrode, gold ...

Embodiment 2

[0039] The electrochemical characterization of embodiment 2DNA sensor

[0040] The surface of different modified electrodes was characterized by cyclic voltammetry and AC impedance method, the results are as follows figure 2 shown. 10.0μL of PBS buffer solution (50.0mmol / L, pH=7.0) containing the target sequence was directly drop-coated on the surface of ssDNA / p-RGO / AuNPs / CILE, and hybridized at room temperature with 0.5% SDS solution and twice Rinse with distilled water to remove unhybridized target sequences, and the electrode after hybridization is denoted as dsDNA / p-RGO / AuNPs / CILE.

[0041] For the results of cyclic voltammetry, see figure 2 A, the electrolyte is 1.0mmol / LK 3 [Fe(CN) 6 ] and 0.5mol / L KCl, the platinum sheet was used as the auxiliary electrode, and the saturated calomel electrode was used as the reference electrode. Different modified electrodes (GO / AuNPs / CILE, CILE, AuNPs / CILE, dsDNA / p-RGO / AuNPs / CILE, p-RGO / CILE, ssDNA / p-RGO / AuNPs / CILE and p-RGO / Au...

Embodiment 4

[0045] The detection of embodiment 4 sensor selectivity

[0046] On the prepared sensor, 10.0 μL containing non-complementary sequence (5'-CATGTACGTTGCGCCAAGTAGT-3'); three-base mismatch sequence (5'-TG T AGTGACA G ATGTGCCGC A A-3'); single base mismatch sequence (5'-TGCAGTGACA G ATGTGCCGCCA-3') and the PBS buffer solution (50.0mmol / L, pH=7.0) of the target sequence were directly drip-coated on the surface of ssDNA / p-RGO / AuNPs / CILE, and after hybridization at room temperature, they were mixed with 0.5% SDS solution and Rinse with double distilled water to remove unhybridized target sequences, and then in 2.0×10 -5 Soak in the methylene blue solution of mol / L concentration for 8 minutes, take it out, wash it with 0.5% SDS solution and secondary water successively, and detect the current of the sensor by differential pulse voltammetry, the results are shown in Figure 4 . The electrolyte was 50.0mmol / LTris-HCl buffer solution, the platinum sheet was used as the auxiliary el...

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Abstract

The invention discloses a novel electrochemical DNA sensor constructed by a nanogold and partially-reduced graphene oxide (p-RGO) modified ionic liquid carbon paste electrode (CILE) as a platform prepared by an electrochemical method, and a method of applying the CILE to detect the Listeria feature gene sequence. 1-hexylpyridiniumhexafluorophosphate as a modifier is used for preparing the substrate electrode CILE, gold nanoparticles are deposited on the surface of the substrate electrode CILE and then the p-RGO is prepared by controlling electrochemical reduction conditions; an amino-modified probe ssDNA is fixed on the surface of the electrode by an amido bond covalent bonding method through carboxyl groups remained on the surface of p-RGO to constitute ssDNA/p-RGO/AuNPs/CILE; methylene blue (MB) as an indicator is used for detecting the hybridization reaction after a target sequence is hybridized, and a differential pulse voltammetry (DPV) is used for detecting the Listeria feature gene segment.

Description

technical field [0001] The invention relates to a preparation and application method of an electrochemical DNA sensor with a novel nanocomposite modified electrode Background technique [0002] Deoxyribose nucleic acid (DeoxyribonucleicAcid, DNA) is the carrier of genetic information, with the function of transmitting and storing information. DNA exists in any organisms, viruses, and pathogenic bacteria, and is of great significance for the detection and diagnosis of various diseases. Since DNA plays an important role in medical diagnosis, environmental monitoring, forensic identification and food hygiene inspection, how to quickly and accurately detect specific DNA sequences is of great significance. Electrochemical DNA sensors have a series of advantages such as rapid detection, simplicity, sensitivity, high selectivity, simple operation, low cost, etc., and have broad application prospects in many fields. [0003] Electrochemical DNA sensors use electrodes as transducer...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N27/327G01N27/48
CPCG01N27/3276G01N27/3278G01N27/48
Inventor 李光九郑雯刘俐华王秀丽陈玮王文成孙伟
Owner QINGDAO UNIV OF SCI & TECH
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