Method for preparing photoelectric adapter sensor for detecting 17beta-estradiol

Abstract

The invention relates to a method for preparing a photoelectric adapter sensor for detecting 17beta-estradiol. The photoelectric adapter sensor takes a prepared cadmium selenide nano particle modified titanium dioxide nano tube as a matrix electrode; after the surface of the electrode is functionalized by chitosan and glutaraldehyde, and a 17beta-estradiol adapter is dropwise added onto the surface of the electrode so as to prepare the 17beta-estradiol photoelectric adapter sensor. Compared with the prior art, the method combines the 17beta-estradiol photoelectric adapter sensor with specific recognition capability with a supersensitive photoelectric analysis technique for detecting an environmental internal-secretion interfering-substance 17beta-estradiol, so that not only is high sensitivity acquired, but also interference of a complex matrix environment is prevented, and high selectivity is achieved; when the method is used in low-concentration 17beta-estradiol detection, a wide working curve range of 5*10<-13> mol / L to 15*10<-12> mol / L is obtained, the minimum detection limit can be 3.3*10<-14> mol / L, and moreover, the 17beta-estradiol photoelectric adapter sensor is simple in preparation method, low in cost and good in stability and repeatability.

Description

technical field

[0001] The invention relates to the technical field of environmental monitoring and nano-modified electrodes, in particular to a method for preparing a photoelectric aptasensor for detecting 17β-estradiol. Background technique

[0002] Endocrine disruptors have a serious impact on the endocrine function of the human body and other organisms, and have attracted much attention in recent years. Among them, 17β-estradiol is considered to be the most harmful environmental endocrine to the endocrine system of humans and animals. It is a natural female hormone, mainly derived from the excrement of humans or livestock, as well as the use and discharge of drugs containing synthetic hormones. When 17β-estradiol enters the human body and other organisms from the external environment through the food chain, it will interfere with normal physiological processes, affect human growth and development, reduce the male birth rate, and increase the incidence of tumors. In recen...

Examples

Embodiment 1

[0026] A highly sensitive and selective photoaptamer sensor for 17β-estradiol constructed on CdSe NPs-TiO 2 NTs as the substrate, the aptamer of 17β-estradiol was modified on CdSe NPs-TiO 2 Inside and outside of the tube of NTs. The specific production process is as follows:

[0027] (1) The titanium plates were mechanically polished with abrasive papers of different finenesses in turn, and then placed in double distilled water and ethanol solutions for ultrasonic cleaning for 5-10 min, respectively. Before anodization, the titanium plate was etched with 18% HCl for 10 min, and then it was placed in a two-electrode system for anodization. The platinum plate was used as the cathode, and the titanium plate was used as the anode. The distance between the two electrodes was 1 cm, and the applied cell voltage was 40 V, at a temperature of 25 °C, anodize for 2 to 3 h. Electrolyte includes 0.3 wt% NH 4 F and 3.0 Vol% H 2 O solution in ethylene glycol. Anodized TiO 2 NTs wer...

Embodiment 2

[0031] A series of 17β-estradiol standard solutions with different concentrations were prepared by diluting with 0.1 mol / L PBS buffer (pH 7.41) after preparing 1 mmol / L 17β-estradiol stock solution with absolute ethanol as solvent. A buffer solution of 0.1 mol / L PBS (pH 7.41) and 0.1 mol / L ascorbic acid (AA) was used as the electrolyte, where AA was used as an electron sacrificial agent. At 0.0 V, the electrodes were kept 5 cm away from the visible light source. CdSe NPs-TiO modified with nucleic acid aptamers 2 In the three-electrode system with NTs as the working electrode, saturated calomel electrode as the reference electrode, and platinum wire as the counter electrode, when adding different concentrations of 17β-estradiol to the electrochemical cell, each sample needs to be reacted for 30 minutes before proceeding. Amperometric i-t curve determination. Due to the specific recognition of the aptamer and its target substance, 17β-estradiol is captured on the electrode su...

Embodiment 3

[0033] CdSe NPs-TiO modified with 17β-estradiol aptamer 2 NTs were placed in 0.1 mol / L PBS + 0.1 mol / L AA (pH 7.41) as electrolyte, and 1.0×10 -12 mol / L 17β-estradiol was mixed with different concentrations of interfering substances in pairs for determination. The interference of six environmental endocrine disruptors, ethinyl estradiol, estriol, nonylphenol, resorcinol, bisphenol A, atrazine and diethyl phthalate, on the determination of 17β-estradiol was investigated experiment. Using the test conditions in Example 2, measure the photocurrent response, the research results show that the influence caused by the photocurrent of other interfering substance 17β-estradiol which is 100 times the concentration of 7β-estradiol is less than 10.0%, such as image 3 shown. It can be seen that the prepared aptasensor has high selectivity to 17β-estradiol, and other six environmental endocrines with similar structures or coexisting with 17β-estradiol do not interfere with its determ...

technical field

[0001] The invention relates to the technical field of environmental monitoring and nano-modified electrodes, in particular to a method for preparing a photoelectric aptasensor for detecting 17β-estradiol. Background technique

[0002] Endocrine disruptors have a serious impact on the endocrine function of the human body and other organisms, and have attracted much attention in recent years. Among them, 17β-estradiol is considered to be the most harmful environmental endocrine to the endocrine system of humans and animals. It is a natural female hormone, mainly derived from the excrement of humans or livestock, as well as the use and discharge of drugs containing synthetic hormones. When 17β-estradiol enters the human body and other organisms from the external environment through the food chain, it will interfere with normal physiological processes, affect human growth and development, reduce the male birth rate, and increase the incidence of tumors. In recen...

Examples

Embodiment 1

[0026] A highly sensitive and selective photoaptamer sensor for 17β-estradiol constructed on CdSe NPs-TiO 2 NTs as the substrate, the aptamer of 17β-estradiol was modified on CdSe NPs-TiO 2 Inside and outside of the tube of NTs. The specific production process is as follows:

[0027] (1) The titanium plates were mechanically polished with abrasive papers of different finenesses in turn, and then placed in double distilled water and ethanol solutions for ultrasonic cleaning for 5-10 min, respectively. Before anodization, the titanium plate was etched with 18% HCl for 10 min, and then it was placed in a two-electrode system for anodization. The platinum plate was used as the cathode, and the titanium plate was used as the anode. The distance between the two electrodes was 1 cm, and the applied cell voltage was 40 V, at a temperature of 25 °C, anodize for 2 to 3 h. Electrolyte includes 0.3 wt% NH 4 F and 3.0 Vol% H 2 O solution in ethylene glycol. Anodized TiO 2 NTs wer...

Embodiment 2

[0031] A series of 17β-estradiol standard solutions with different concentrations were prepared by diluting with 0.1 mol / L PBS buffer (pH 7.41) after preparing 1 mmol / L 17β-estradiol stock solution with absolute ethanol as solvent. A buffer solution of 0.1 mol / L PBS (pH 7.41) and 0.1 mol / L ascorbic acid (AA) was used as the electrolyte, where AA was used as an electron sacrificial agent. At 0.0 V, the electrodes were kept 5 cm away from the visible light source. CdSe NPs-TiO modified with nucleic acid aptamers 2 In the three-electrode system with NTs as the working electrode, saturated calomel electrode as the reference electrode, and platinum wire as the counter electrode, when adding different concentrations of 17β-estradiol to the electrochemical cell, each sample needs to be reacted for 30 minutes before proceeding. Amperometric i-t curve determination. Due to the specific recognition of the aptamer and its target substance, 17β-estradiol is captured on the electrode su...

Embodiment 3

[0033] CdSe NPs-TiO modified with 17β-estradiol aptamer 2 NTs were placed in 0.1 mol / L PBS + 0.1 mol / L AA (pH 7.41) as electrolyte, and 1.0×10 -12 mol / L 17β-estradiol was mixed with different concentrations of interfering substances in pairs for determination. The interference of six environmental endocrine disruptors, ethinyl estradiol, estriol, nonylphenol, resorcinol, bisphenol A, atrazine and diethyl phthalate, on the determination of 17β-estradiol was investigated experiment. Using the test conditions in Example 2, measure the photocurrent response, the research results show that the influence caused by the photocurrent of other interfering substance 17β-estradiol which is 100 times the concentration of 7β-estradiol is less than 10.0%, such as image 3 shown. It can be seen that the prepared aptasensor has high selectivity to 17β-estradiol, and other six environmental endocrines with similar structures or coexisting with 17β-estradiol do not interfere with its determ...

Images