WO2023000909A1

WO2023000909A1 - Minute-scale high-sensitivity micro-current controlled raman detection apparatus and method

Info

Publication number: WO2023000909A1
Application number: PCT/CN2022/100614
Authority: WO
Inventors: 张玉芝
Original assignee: 张玉芝
Priority date: 2021-07-19
Filing date: 2022-06-23
Publication date: 2023-01-26
Also published as: CN115639180A

Abstract

A minute-scale high-sensitivity micro-current controlled Raman detection apparatus and method. The Raman detection device comprises a Raman spectrum detection module (1), a sample acquisition module (2), a positive electrode module (3), a negative electrode module (4), a power supply module (5) and a multi-axis adjustable support (6). A substance to be detected is caused to be at a detection hot spot by a micro-current, and the number of free electrons of a SERS chip is greatly increased by means of applying an electric field; the method has high detection sensitivity and a rapid detection process, and the device is compact in structure and low in cost.

Description

A minute-level high-sensitivity micro-current control Raman detection device and method

related application

This application claims the priority of the Chinese invention patent application: 202110815311.3 filed on July 19, 2021, entitled "A Raman detection device and method for minute-level high-sensitivity micro-current control".

technical field

The invention relates to the field of optical detection, in particular to the field of SERS surface-enhanced Raman detection of microorganisms such as viruses and bacteria, and volatile organic substances exhaled by a human body.

Background technique

In recent years, spectral detection technology has developed rapidly, and it is a highly sensitive, fast and efficient imaging detection method. Among them, surface-enhanced Raman spectroscopy (SERS) has the advantages of label-free detection of molecular fingerprints and single-molecule detection.

However, the Raman scattering signal intensity of substances is usually relatively low, so that the detection sensitivity is not high due to scattering. For the collected samples, the Raman detection signal intensity is still very low, or even undetectable.

At present, there are mainly the following ways to further enhance the surface-enhanced Raman spectroscopy SERS:

The first is the microfluidic chip technology. Since the laser spot can be directly focused on the tiny channel of the microfluidic chip, the detection sensitivity is very high. However, the production cost of the microfluidic chip itself is high, the tiny channels are easily blocked by impurities, and the cleaning process for repeated use is complicated, resulting in high overall detection costs, and its detection is limited to the detection of liquid samples.

The second is to enhance surface-enhanced Raman spectroscopy (SERS) by optimizing the design of the chip, such as a nanoparticle chip, which forms a nanocage hotspot on its top, so that the substance to be tested can be better confined to the hot spot, thereby improving detection sensitivity. Such methods have limited enhancement to enhanced Raman spectroscopy detection, and the chip production process is complicated, the cost is high, and the chip reusability is poor, so it is difficult to apply to large-scale detection.

Contents of the invention

The purpose of the present invention is to provide a minute-level high-sensitivity micro-current control Raman detection method and device to achieve high detection sensitivity, rapid detection process, compact device structure and low cost.

The technical scheme that the present invention solves technical problem is:

A Raman spectrum detection device, characterized in that the detection device includes a Raman spectrum detection module and a current forming module, wherein,

The Raman spectrum detection module is used to perform Raman detection on the target sample, the target sample has fluidity or the target sample is placed in a fluid substance;

The current forming module is arranged around the target sample to generate current in the target sample.

Preferably, the current forming module has a first electrode and a second electrode, at least one of the first electrode and the second electrode has a discharge tip, and the discharge tip is arranged on the detection light of the Raman spectrum detection module. near the focus.

Preferably, the other of the first electrode and the second electrode is arranged on the periphery of the target sample, and the detection light of the Raman spectrum detection module is focused on the target sample, preferably in the middle of the target sample .

Preferably, it also includes a multi-axis adjustable support, the multi-axis adjustable support has a fixed base and a movable end, the Raman spectrum detection module is fixedly installed on the movable end of the multi-axis adjustable support, the The movable end of the multi-axis adjustable bracket can three-dimensionally adjust the position of the Raman detection module, and/or adjust the azimuth and elevation angles of the Raman spectrum detection module.

Preferably, the Raman spectrum detection module emits laser light onto the target sample, collects returned Raman scattered light, and processes it to obtain fingerprint spectrum information of the target sample.

Preferably, the electrode disposed near the focal point of the detection light of the Raman spectrum detection module has a discharge tip, the discharge tip is in contact with the target sample, another electrode surrounds the target sample, and the The discharge tip and the focal point of the detection light move cooperatively on the target sample.

Preferably, it also includes a sample collection module, the target sample is arranged on the sample collection module, the sample collection module can be a discontinuous conductive sample carrying module, preferably a sample with a plurality of discontinuous conductors on it (plane A plurality of small discontinuous conductors are embedded on the insulating substrate) carrying modules, preferably, the sample collection module is a metal nanoparticle chip. This can further enhance the Raman effect.

Preferably, the position of the discharge tip can be moved freely so that current can be applied to different positions of the sample collection module, and preferably, a power module is also included, the positive pole and negative pole of the power module are respectively connected to the first electrode and the The second electrode, the power supply module also applies an electric field to the sample collection module.

On the other hand, the present invention provides a kind of Raman detection method, it is characterized in that, described method comprises:

(1) Applying a first voltage to the target sample to form a current therein, the target sample has fluidity or the target sample is placed in a fluid substance;

(2) Raman detection is performed on the target sample with current flowing therethrough.

Preferably, the method comprises contacting the target sample with a discharge tip, the discharge tip being connected to a first electrode having a polarity opposite to that charged by the target sample, and another electrode surrounding the target sample, preferably Preferably, the target sample is placed on the discontinuous nano-gold material layer, and the discharge tip is connected to the discontinuous nano-gold material layer, preferably, the discharge tip and the focal point of the detection light detected by Raman cooperate on the Move on the target sample.

Technical effect:

Compared with the prior art, the present invention charges the substance to be tested by micro-current, and the substance to be tested is enriched near the discharge tip of the positive electrode along with the current flow, which greatly improves the sample concentration at the detection position, and can adjust the discharge of the positive electrode The tip position realizes multi-point and multiple measurements of the same chip, which improves the efficiency of the acquisition chip. The invention overcomes the disadvantages of the prior art, such as high requirements on detection chips, poor reusability and high detection cost, and has the advantages of high detection sensitivity, rapid detection process and low cost.

The invention greatly increases the number of free electrons of the metal nanoparticle chip through the applied electric field, the method of the invention has high detection sensitivity, the detection process is rapid, the device of the invention has a compact structure and low cost.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention. In the figure, 1 is a Raman spectrum detection module, 2 is a sample collection module, 3 is a positive module, 4 is a negative module, 5 is a power module, and 6 is a multi-axis adjustable support.

Figure 2 is a schematic structural view of another embodiment of the present invention, in which, 1 is a Raman spectrum detection module, 2 is a sample collection module, 2-1 is a discontinuous nano-gold material layer, 3 is a positive module, and 4 is a negative electrode module, 5 is a power module, and 6 is a multi-axis adjustable support.

Fig. 3 is a Raman spectrogram of Escherichia coli detection using the device of the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only, and are not intended to limit the scope of the present invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present invention.

A schematic structural diagram according to an embodiment of the present invention is shown in the accompanying drawings. The figures are not drawn to scale, with certain details exaggerated and possibly omitted for clarity. The shapes of the various regions and layers shown in the figure, as well as their relative sizes and positional relationships are only exemplary, and may deviate due to manufacturing tolerances or technical limitations in practice, and those skilled in the art will Regions/layers with different shapes, sizes, and relative positions can be additionally designed as needed.

As shown in Figure 1, the minute-level high-sensitivity micro-current controlled Raman detection device in this embodiment includes a Raman spectrum detection module 1, a sample collection module 2, a positive electrode module 3, a negative electrode module 4, a power module 5 and a multi-axis Adjustable stand6. Among them, the multi-axis adjustable support 6 has a fixed base and a movable end, and the Raman spectrum detection module 1 is fixedly installed on the movable end of the multi-axis adjustable support 6, and the movable end of the multi-axis adjustable support 6 can be adjusted and pulled in a three-dimensional straight line. The position of the Raman detection module 1, and the connection position between the movable end and the Raman spectrum detection module has a ball-axis structure, which can adjust the angle of the Raman spectrum detection module from multiple angles. It should be noted that the multi-axis adjustable support 6 can adopt any existing support capable of position and angle adjustment, and there is no limitation here.

The positive electrode module is fixed on the Raman spectrum detection module or the positive electrode module is fixed by another adjustable bracket, and it has a discharge tip, and the discharge tip is arranged near the focal point of the detection light of the Raman spectrum detection module.

The position of the discharge tip of the positive electrode module can be adjusted according to the requirement, and it is preferably located near the focus of the laser emitted by the Raman spectrum detection module. The Raman detection module can move in coordination with the discharge tip of the positive electrode module, so that the position of the discharge tip is continuously located near the focus of the Raman spectroscopy module, and the position on the sample collection module can be constantly changed. The negative module 4 surrounds the sample collection module; the positive and negative poles of the power supply module 5 are respectively connected to the positive module and the negative module through wires.

In the above embodiment, in order to ensure the detection effect, preferably, the Raman spectrum detection module is a 532nm and 785nm dual-wavelength spectrum detection module, its outgoing optical path is placed perpendicular to the sample collection module, and the laser focus is located at the on the sample collection module. Preferably, the sample collection module is a nano-gold SERS chip with an ordered array substrate. Preferably, the shape of the negative electrode module matches the sample collection module, and the size is slightly smaller than that of the sample collection module, and the negative electrode module is arranged on the periphery of the sample collection module during use. Preferably, the power supply module is a high voltage, high internal resistance power supply module, and its voltage and internal resistance can be adjusted adaptively, the voltage adjustment range is 0V-10000V, and the resistance adjustment range is 100Ω-100kΩ. Preferably, the discharge tip of the positive module and the negative module are made of red copper. Preferably, the power module is a high voltage, high internal resistance power module.

The working process of the minute-level high-sensitivity micro-current controlled Raman detection device in this embodiment is as follows: use the multi-axis adjustable bracket as a structure to support the entire device, adjust the position and detection angle of the Raman spectrum detection module, so that Focus on the sample on the sample collection module; collect the sample to be tested on the sample collection module, the sample to be tested (for example, microorganisms such as viruses and bacteria and volatile organic compounds exhaled by the human body, these samples are adsorbed in the gas or liquid carrier, It is better to add the bacterial culture liquid in the liquid) after being processed, it is better to be in a liquid state; the laser focus of the Raman spectrum detection module is set to the target position on the sample collection module; the discharge tip of the positive electrode module is set to the vicinity of the laser focus , and lightly contact with the sample to be tested; set the negative module around the sample collection module and lightly contact with the sample to be tested; turn on the power module, and adjust the current (uA to the mA level) to ensure that the structure of the substance to be tested is not destroyed. Under the action of the micro-current, the substance to be tested in the sample to be tested is charged and gathers near the discharge tip of the positive electrode module along with the current flow; at the same time, all The above-mentioned power module can also be connected with another group of electrodes, and this group of electrodes is arranged on the upper and lower sides of the sample collection module (if arranged on the upper and lower sides, the form of grid electrodes can be used to avoid blocking the laser) or on the left and right sides. The sample collection module applies an electric field to greatly increase the free electrons contained in the nano-gold material in the sample collection module; the Raman spectrum detection module emits laser light, and the focus is irradiated on the sample collection module, and the returned substance to be tested is collected at the same time The Raman spectrum signal is received and processed by its built-in spectrometer to obtain the fingerprint spectrum information of the substance to be tested, and the detection is completed.

In some other embodiments, a control module can be added for automatic control of the whole device.

It should be noted that in this embodiment, the target sample will carry a negative charge when it is charged as an example. Therefore, the anode is provided with a discharge tip to converge the target sample. It does not rule out that under special circumstances, the target sample carries a positive charge when it is charged. If this is the case, the cathode is set with a discharge tip to converge the target sample, that is, the structure and position of the cathode and anode can be interchanged, and the charge is carried out according to the charge of the target sample. Adjustment.

As shown in FIG. 3 , it is the Raman spectrum of Escherichia coli detection using the detection device of the present invention. During detection, E. coli is adsorbed to the liquid. If there are few strains in the collection environment, culture liquid can be used. Then, the liquid is applied to the surface of the sample collection module, and the sample collection module is placed on the sample carrying platform in the device. Raman In the focused area of the spectrum, the electrodes are set up for Raman detection. The figure shows the Raman spectrum collected at the tip of the positive electrode, the Raman spectrum at the negative electrode, and the spectrum without applying current. It can be seen that only the Raman spectrum collected at the tip of the positive electrode contains the Raman spectrum of Escherichia coli. All characteristic peaks of the spectrum——650.950.1125.1250nm, and all characteristic peaks are not detected in the other two spectra. Therefore, it can be proved that the method of the present invention can carry out the Raman detection of the sample more effectively and accurately, with higher detection accuracy.

Example 2

In some other embodiments, the basic settings are the same as in Embodiment 1. Specifically, as shown in Figure 2, the upper surface of the sample collection module 2 is uniformly plated with a discontinuous nano-gold material layer 2-1, and the positive electrode module 3 is integrated at the bottom of the sample collection module 2 or installed under the sample collection module 2, and its discharge The tip can be connected with any discontinuous nano-gold material layer 2-1. The negative module 4 surrounds the sample collection module; the positive and negative poles of the power supply module are respectively connected to the positive module and the negative module through wires

The working process of the minute-level high-sensitivity micro-current controlled Raman detection device in this embodiment is roughly the same as in Embodiment 1, and reference is made to Embodiment 1 for parts not described in this embodiment.

Specifically, when it works, the laser focus of the Raman spectrum detection module 1 is set to directly above the target nano-gold material layer; then the discharge tip of the anode module is connected to the nano-gold material layer; the power supply is turned on The module adjusts the current to ensure that the structure of the substance to be tested is not destroyed. Under the action of the micro-current, the substance to be tested in the sample to be tested is charged and gathers to the position of the target nano-gold material layer along with the current flow; and then uses Raman The detection module performs Raman detection of the target substance, and other steps are the same as in Example 1.

In general, the minute-level high-sensitivity micro-current controlled Raman detection device and the corresponding detection method of the present invention, compared with the prior art, allow the substance to be tested to converge to the detection hotspot through the micro-current, and the applied electric field is greatly increased The number of free electrons in the metal nanoparticle chip, the method of the invention has high detection sensitivity, rapid detection process, and the device of the invention has compact structure and low cost.

It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and not to limit the present invention. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present invention shall fall within the protection scope of the present invention. Furthermore, it is intended that the appended claims of the present invention embrace all changes and modifications that come within the scope and metesques of the appended claims, or equivalents of such scope and metes and bounds.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims

A minute-level high-sensitivity micro-current control Raman spectrum detection device, characterized in that the detection device includes a Raman spectrum detection module and a current forming module, wherein,

The Raman spectrum detection module is used to perform Raman detection on the target sample, the target sample has fluidity or the target sample is placed in a fluid substance;

The current forming module is arranged around the target sample to generate current in the target sample.
The Raman spectroscopy detection device according to claim 1, wherein the current forming module has a first electrode and a second electrode, at least one of the first electrode and the second electrode has a discharge tip, and the The discharge tip is arranged near the focal point of the detection light of the Raman spectrum detection module.
The Raman spectrum detection device according to claim 2, wherein the other of the first electrode and the second electrode is arranged on the periphery of the target sample, and the detection light of the Raman spectrum detection module is focused on The target sample is preferably focused on the middle of the target sample.
The Raman spectrum detection device according to claim 2, further comprising a multi-axis adjustable support, the multi-axis adjustable support has a fixed base and a movable end, and the Raman spectrum detection module 1 is fixedly installed On the movable end of the multi-axis adjustable bracket 6, the movable end of the multi-axis adjustable bracket can three-dimensionally adjust the position of the Raman detection module, and/or adjust the azimuth angle of the Raman spectrum detection module and pitch angle.
The Raman spectrum detection device according to claim 2, wherein the Raman spectrum detection module emits laser light onto the target sample, and collects the returned Raman scattered light, and processes to obtain the fingerprint spectrum information of the target sample .
The Raman spectrum detection device according to claim 2, wherein the electrode disposed near the focal point of the detection light of the Raman spectrum detection module has a discharge tip, and the discharge tip is in contact with the target sample, A further electrode surrounds the target sample, and preferably the discharge tip and the focus of the detection light move cooperatively on the target sample.
The Raman spectroscopy detection device according to claim 2, further comprising a sample collection module, the target sample is set on the sample collection module, preferably, the sample collection module is a metal nanoparticle chip.
The Raman spectroscopy detection device according to claim 7, wherein the discharge tip can move freely so that current can be applied to different positions of the sample collection module, preferably, it also includes a power module, and the power module The positive pole and the negative pole of each are respectively connected to the first electrode and the second electrode, and the power supply module also applies an electric field to the sample collection module.
A kind of Raman detection method is characterized in that, described method comprises:

(1) Applying a first voltage to the target sample to form a current therein, the target sample has fluidity or the target sample is placed in a fluid substance;

(2) Raman detection is performed on the target sample with current flowing therethrough.
The method according to claim 9, characterized in that the method comprises contacting the target sample with a discharge tip connected to a first electrode having a polarity opposite to that of the charge of the target sample, another The electrode surrounds the target sample, preferably, the target sample is placed on the discontinuous nano-gold material layer, and the discharge tip is connected to the discontinuous nano-gold material layer, preferably, the discharge tip and the Raman detection The focus of the detection light moves in concert on the target sample.