Surface-enhanced Raman scattering active substrate and preparation method thereof

Abstract

The invention provides a high-responsive surface-enhanced Raman scattering active substrate and a preparation method thereof, and prepares a surface-enhanced Raman substrate comprising a III-V semiconductor substrate having a porous ravine surface and Au nanoparticles distributed on the substrate The scattering active substrate comprises the steps of: etching the surface of the substrate to form a rough surface; and depositing Au nanoparticles on the surface of the substrate with a porous trench structure by an electrochemical deposition method. The preparation method is not only simple, low cost, and easy to implement; moreover, there is no nanoparticle aggregation in the surface-enhanced Raman scattering active substrate prepared by this method, and it has high electric field strength and photogenerated carrier lifetime and high The Raman signal intensity is high, so that it has a high reutilization rate and detection sensitivity, and it can be used in the detection of ultra-low molecular concentration SERS, so that it has a wide range of applications.

Description

technical field

[0001] The invention relates to the technical fields of surface nanoscience, electrochemistry, biological science and laser Raman detection, in particular to a preparation method of a high-responsivity surface-enhanced Raman scattering active substrate. Background technique

[0002] Surface-enhanced Raman scattering (Surface-enhanced Raman scattering, SERS) spectroscopy, due to its extremely high sensitivity, can study the structural information of substances at the molecular level and realize the detection of single molecules, and has become a promising surface spectroscopy technology. . Among them, precious metals such as silver, gold, copper and alkali metals have high SERS activity, and silver has the strongest enhancement ability, followed by gold and copper; at the same time, the activity of SERS substrate is largely the same as that of metal nanomaterial The size and shape of the particles are related to the surface topography of the supporting substr...

Examples

Embodiment 1

[0025] a) Perform photoelectrochemical etching treatment on the surface of the GaN substrate: wash the GaN substrate with acetone, ethanol and deionized water in sequence, immerse the GaN substrate in 0.5M / L dilute sulfuric acid, and add a bias voltage of 3V and UV light source, anode etching for 15min. Of course, in other embodiments, etching may also be performed by immersing in an acidic solution such as hydrofluoric acid. After the etching is completed, it is cleaned with deionized water, so that the GaN substrate 110 with a porous and ravine shape is formed.

[0026] b) Using cyclic voltammetry, deposit Au nanoparticles 120 on the surface of the GaN substrate to prepare an Au-GaN-based SERS active substrate: 1 mM / L HAuCl 4 Add 1M / L NaCl (or KNO 3 or KCl) as the electrolyte, using cyclic voltammetry to deposit Au nanoparticles 120 on the surface of the GaN substrate. In a preferred embodiment, the scanning voltage range is -2.0-0.5V, the scanning rate is 50mV / s, and the...

Embodiment 2

[0029] a) The surface of the GaN substrate is subjected to photoelectrochemical etching treatment: the GaN substrate is cleaned with acetone, ethanol and deionized water in sequence, and then dried with nitrogen; the GaN substrate is immersed in 0.5M / L dilute sulfuric acid, and Add a bias voltage of 5V and an ultraviolet light source, etch the anode for 45 minutes; wash with deionized water after etching, and blow dry with nitrogen, thus forming a GaN substrate 110 with a porous groove shape.

[0030] b) Using cyclic voltammetry, deposit Au nanoparticles 120 on the surface of the GaN substrate to prepare an Au-GaN-based SERS active substrate: 1 mM / L HAuCl 4 Add 0.5M / L NaCl (or KNO 3 ) as an electrolyte, Au nanoparticles 120 are deposited on the surface of the GaN substrate by cyclic voltammetry. In a preferred embodiment, the scanning voltage range is -2.0-0.5V, the scanning rate is 50mV / s, and the number of scanning cycles is 20. After the deposition was completed, it was t...

Embodiment 3

[0033] a) Electrochemical etching treatment is performed on the surface of the GaN substrate: the GaN substrate is washed with acetone, ethanol and deionized water in sequence; the substrate is immersed in ionic liquid 1-butyl-3-methylimidazole perchlorate, And add a bias voltage of 3V, react for 40 minutes, carry out anodic etching on the GaN substrate, and rinse with deionized water after etching, thus forming a GaN substrate 110 with a porous and ravine shape, the SEM image of which is shown in FIG. 3 .

[0034] b) Using cyclic voltammetry, deposit Au nanoparticles 120 on the surface of the GaN substrate to prepare an Au-GaN-based SERS active substrate: 1 mM / L HAuCl 4 Add 0.5M / L NaCl (or KNO 3 ) as an electrolyte, Au nanoparticles 120 are deposited on the surface of the GaN substrate by cyclic voltammetry. In a preferred embodiment, the scanning voltage range is -2.0-0.5V, the scanning rate is 50mV / s, and the number of scanning cycles is 15. After the deposition was compl...

technical field

[0001] The invention relates to the technical fields of surface nanoscience, electrochemistry, biological science and laser Raman detection, in particular to a preparation method of a high-responsivity surface-enhanced Raman scattering active substrate. Background technique

[0002] Surface-enhanced Raman scattering (Surface-enhanced Raman scattering, SERS) spectroscopy, due to its extremely high sensitivity, can study the structural information of substances at the molecular level and realize the detection of single molecules, and has become a promising surface spectroscopy technology. . Among them, precious metals such as silver, gold, copper and alkali metals have high SERS activity, and silver has the strongest enhancement ability, followed by gold and copper; at the same time, the activity of SERS substrate is largely the same as that of metal nanomaterial The size and shape of the particles are related to the surface topography of the supporting substr...

Examples

Embodiment 1

[0025] a) Perform photoelectrochemical etching treatment on the surface of the GaN substrate: wash the GaN substrate with acetone, ethanol and deionized water in sequence, immerse the GaN substrate in 0.5M / L dilute sulfuric acid, and add a bias voltage of 3V and UV light source, anode etching for 15min. Of course, in other embodiments, etching may also be performed by immersing in an acidic solution such as hydrofluoric acid. After the etching is completed, it is cleaned with deionized water, so that the GaN substrate 110 with a porous and ravine shape is formed.

[0026] b) Using cyclic voltammetry, deposit Au nanoparticles 120 on the surface of the GaN substrate to prepare an Au-GaN-based SERS active substrate: 1 mM / L HAuCl 4 Add 1M / L NaCl (or KNO 3 or KCl) as the electrolyte, using cyclic voltammetry to deposit Au nanoparticles 120 on the surface of the GaN substrate. In a preferred embodiment, the scanning voltage range is -2.0-0.5V, the scanning rate is 50mV / s, and the...

Embodiment 2

[0029] a) The surface of the GaN substrate is subjected to photoelectrochemical etching treatment: the GaN substrate is cleaned with acetone, ethanol and deionized water in sequence, and then dried with nitrogen; the GaN substrate is immersed in 0.5M / L dilute sulfuric acid, and Add a bias voltage of 5V and an ultraviolet light source, etch the anode for 45 minutes; wash with deionized water after etching, and blow dry with nitrogen, thus forming a GaN substrate 110 with a porous groove shape.

[0030] b) Using cyclic voltammetry, deposit Au nanoparticles 120 on the surface of the GaN substrate to prepare an Au-GaN-based SERS active substrate: 1 mM / L HAuCl 4 Add 0.5M / L NaCl (or KNO 3 ) as an electrolyte, Au nanoparticles 120 are deposited on the surface of the GaN substrate by cyclic voltammetry. In a preferred embodiment, the scanning voltage range is -2.0-0.5V, the scanning rate is 50mV / s, and the number of scanning cycles is 20. After the deposition was completed, it was t...

Embodiment 3

[0033] a) Electrochemical etching treatment is performed on the surface of the GaN substrate: the GaN substrate is washed with acetone, ethanol and deionized water in sequence; the substrate is immersed in ionic liquid 1-butyl-3-methylimidazole perchlorate, And add a bias voltage of 3V, react for 40 minutes, carry out anodic etching on the GaN substrate, and rinse with deionized water after etching, thus forming a GaN substrate 110 with a porous and ravine shape, the SEM image of which is shown in FIG. 3 .

[0034] b) Using cyclic voltammetry, deposit Au nanoparticles 120 on the surface of the GaN substrate to prepare an Au-GaN-based SERS active substrate: 1 mM / L HAuCl 4 Add 0.5M / L NaCl (or KNO 3 ) as an electrolyte, Au nanoparticles 120 are deposited on the surface of the GaN substrate by cyclic voltammetry. In a preferred embodiment, the scanning voltage range is -2.0-0.5V, the scanning rate is 50mV / s, and the number of scanning cycles is 15. After the deposition was compl...

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