CN102735564A - High-sensitive biochemical sensor based on resonance oscillation type micro cantilever beam structure - Google Patents

Abstract

The invention discloses a highly sensitive biochemical sensor based on a resonant micro-cantilever beam structure. The biochemical sensor includes a resonant cavity, a cantilever beam and a Whist bridge detection circuit, wherein a micro-column structure (3 ) and a liquid storage tank (4), and a leak hole (5) for flowing out biochemical solution is etched; the supporting end of the cantilever beam is connected to the Whist bridge detection circuit, and the Whist bridge detection circuit It consists of four U-shaped piezoresistive strips (1), three input electrodes (8, 9, 10) and two output electrodes (7, 11), and the four piezoresistive strips (1) pass through signal transmission lines (2 ) are connected to the input electrodes (8, 9, 10) and the output electrodes (7, 11). The biochemical sensor perceives tiny biochemical molecules by detecting the frequency change caused by the adsorption of the analyte, has high sensitivity, can detect biochemical molecules with tiny masses, and can be widely used in engineering fields such as medicine and chemical engineering.

Description

Highly sensitive biochemical sensor based on resonant micro-cantilever structure

technical field

The invention relates to the fields of MEMS, biomedicine and chemical engineering, in particular to a highly sensitive biochemical sensor based on a resonant micro-cantilever beam structure.

Background technique

Since the 1970s, resonant sensors have developed rapidly on the basis of electronic technology, testing technology, computing technology and semiconductor integrated circuit technology ^[1] . With the rapid development of MEMS technology, the size of resonant sensors has been reduced to micron, submicron or even nanometer level, which can perform high-precision measurement of various physical quantities such as temperature, thermal energy, magnetic field and mass, so it is widely used in chemical analysis. , biological testing, pharmaceutical screening and environmental monitoring and other fields.

In recent years, research on high-sensitivity biochemical detection based on micro-cantilever structure has become a research hotspot ^[2] . In 2000, HG.Craighead et al. from Cornell University published an article on the detection of cells by a resonant micromechanical cantilever ^[3] . A 100μm×20μm×0.32μm Si ₃ N ₄ cantilever beam was prepared by PECVD. After coating the O157:H7 antibody on its front section, E.coli cells could be selectively adsorbed. The cantilever beam was excited by thermal noise, and a laser PSD detection system was used Detect the vibration frequency of the cantilever beam, the minimum detectable frequency change is about 10Hz, and the corresponding minimum detectable mass in air is about 1.5pg. In 2004, R. Bashir and others from Purdure University in the United States made a smaller 3.6μm×1.7μm×0.03μm single crystal silicon cantilever beam with SOI silicon wafers. The resonance frequency is about 1.2MHz and the detection sensitivity is about 6.3Hz. /ag, a smallpox virus (9fg) was detected in the air using thermal noise excitation and laser PSD detection.

However, there are still many technical problems in the sensor based on the cantilever beam structure, such as: the large-area adsorption causes the change of the elastic constant of the cantilever beam, and the measurement error caused by the frequency offset; the quality factor of the cantilever beam in the liquid biochemical environment is greatly reduced ^{.【 4]} , leading to a decrease in detection sensitivity and so on. In addition, for portable devices, a highly sensitive self-detection structure is crucial. Although the commonly used optical detection has the advantage of high sensitivity, the optical components will increase the volume and cost of the system. Therefore, there is an urgent need to develop portable, highly sensitive biochemical sensors based on novel cantilever beam structures.

references:

[1] R.T.Howe, R.S.Muller, K.J.Gabriel and W.S.N.Trimmer, Silicon micro-mechanics: sensor and actuators on a chip, IEEE Spectrum, 7, 29-35, 1990.

【2】A.Hierlemann, O.Brand, C.Hagleiter and H.Baltes, Micro-fabrication techniques for chemical/biosensor, proceedings of the IEEE, 6, 839-863, 2003.

【3】B.Ilic, D.Czaplewski, H.G.Craighead, P.Neuzil, C.Campagnolo and C.Batt, Mechanical resonant immunospecific biological detector, Applied Physics Letter, 77, 450-452, 2000.

【4】Ekrem Bayraktar, Deniz Eroglu, Ata Tuna Cifilik, A MEMS based grabimetric resonator for mass sensing applications, IEEE ^24th International Conference, 817-820, 2011.

Contents of the invention

(1) Technical problems to be solved

In order to realize the real-time on-site high-sensitivity detection of the molecules to be measured, it is necessary to make technological breakthroughs in the aspects of high-sensitivity frequency detection technology, elimination of frequency measurement errors caused by adsorption, and reduction of the impact of the detection environment on device stability. The present invention proposes a A highly sensitive biochemical sensor based on a resonant micro-cantilever structure. A local modification structure is designed at the free end of the cantilever beam, which can eliminate the frequency measurement error caused by large-area adsorption, and at the same time reduce the influence of the solution on the quality factor of the cantilever beam; Detects the frequency change of the cantilever beam, which is very suitable for portable applications.

(2) Technical solution

In order to realize real-time high-sensitivity detection of molecules to be tested, the present invention provides a highly sensitive biochemical sensor based on a resonant micro-cantilever beam structure, which includes a resonant cavity, a cantilever beam and a Whist bridge detection circuit, wherein the cantilever beam The free end of the cantilever beam is etched with a microcolumn structure (3) and a liquid storage tank (4), and is etched with a leak hole (5) for flowing out biochemical solution; the support end of the cantilever beam is connected to the whist bridge Detection circuit, the Whistler bridge detection circuit is composed of four U-shaped piezoresistive strips (1), three input electrodes (8, 9, 10) and two output electrodes (7, 11), four The piezoresistive strip (1) is connected to input electrodes (8, 9, 10) and output electrodes (7, 11) through signal transmission lines (2).

In the above scheme, the biochemical sensor uses the frequency response of the cantilever beam to detect biochemical molecules with high sensitivity. The surface modification of the cantilever beam has a detection monolayer structure (12) that can specifically respond to the molecule to be tested, and adsorbs the molecule to be tested. After (13), the quality of the cantilever is changed, which eventually leads to the change of the resonant frequency of the cantilever; the mass of the biochemical molecule is obtained by using the whist bridge detection circuit to detect the frequency change before and after the adsorption of biochemical molecules.

In the above solution, the liquid storage tank (4) is used for local modification and detection of the monomolecular layer to reduce the frequency change caused by the influence of large-area adsorption on the elastic constant of the cantilever beam.

In the above solution, the microcolumn structure (3) is used to increase the adsorption area and improve the detection limit.

In the above scheme, the liquid leakage hole (5) is made in the liquid storage tank (4) to ensure that after the adsorption reaction in the liquid storage tank is completed, the waste liquid is discharged from the through hole and does not remain in the cantilever beam .

In the above solution, the driving mode of the cantilever beam is any one or more of piezoelectric, electrostatic, electromagnetic, thermoelectric or optical driving.

In the above solution, in the Wheatstone bridge detection circuit, the input electrodes (9) are connected to the power signal, the output electrodes (7, 11) are used as output electrodes, and the electrical input electrodes (8, 10) are grounded to the signal.

In the above scheme, one of the resistors in the Whist bridge detection circuit is a U-shaped piezoresistive strip (1) at the support end of the cantilever beam, and the resonant frequency measurement of the cantilever beam is completed by the Whist bridge detection circuit, The U-shaped piezoresistive strip (1) is used to improve the ability to bind current.

In the above scheme, the four piezoresistive strips (1) in the Whist bridge detection circuit are all "U"-shaped piezoresistive strips, and the four piezoresistive strips (1) are formed by ion implantation at the same time, maximizing The consistency of resistance is guaranteed, and the measurement accuracy is effectively improved, and the effective resistance value of each piezoresistive strip (1) is greater than or equal to 1kΩ.

In the above solution, an isolation groove structure is etched between the transmission lines of the Whistler bridge detection circuit to reduce signal crosstalk between the transmission lines and ensure the measurement accuracy of the Whistler bridge detection circuit.

(3) Beneficial effects

As can be seen from the foregoing technical scheme, the beneficial effects of the present invention are:

1. The high-sensitivity biochemical sensor based on the resonant cantilever beam structure provided by the present invention, when the cantilever beam resonates at the resonance frequency, the displacement change will cause the resistance change of the piezoresistive strip at the end of the cantilever beam, thereby causing the Whisper resistance on the cantilever beam substrate. The output voltage of the special bridge circuit changes. A liquid storage tank structure with micropillars is designed at the free end of the cantilever beam for local adsorption of molecules to be measured, eliminating the change in the elastic constant of the cantilever beam caused by large-area adsorption, resulting in measurement errors caused by frequency changes, while reducing The influence of the solution on the quality factor of the cantilever beam is eliminated; and the adsorption area is increased through the micro-column design, and the detection limit is improved. Micro through holes are made in the liquid storage tank structure to ensure that after the adsorption reaction in the liquid storage tank is completed, the waste liquid is discharged from the through holes and does not remain on the cantilever beam. The sensor with resonant micro-cantilever beam structure has high sensitivity, can detect biochemical molecules with tiny mass, and can be widely used in engineering fields such as medicine and chemical industry.

2. The high-sensitivity biochemical sensor based on the resonant cantilever beam structure provided by the present invention can realize the self-detection function by making the detection circuit on the substrate, and then can abandon the huge optical detection equipment, reducing the detector’s The volume realizes the portability of the detection equipment, which is also the advantage of the present invention.

3. The high-sensitivity biochemical sensor based on the resonant micro-cantilever beam structure provided by the present invention improves the effective area of the modification area and the adsorption capacity of the molecules to be measured by etching the micro-column structure and the liquid storage tank structure at the front end of the cantilever beam.

4. In the high-sensitivity biochemical sensor based on the resonant micro-cantilever beam structure provided by the present invention, in the whist bridge detection circuit, the use of "U" type piezoresistive strips can better restrain the current, and the whist bridge detection circuit The four piezoresistive strips are formed by ion implantation at the same time, which ensures the consistency of their initial resistance values.

5. The high-sensitivity biochemical sensor based on the resonant micro-cantilever beam structure provided by the present invention uses highly doped ion implantation to form wires connecting four piezoresistive strips, and isolation grooves are carved between the wires to reduce signal crosstalk between wires. The minimum effective resistance of each piezoresistor cannot be less than 1kΩ, so as to ensure that the output signal of the Whistler bridge is greater than the noise of the external processing circuit.

6. The high-sensitivity biochemical sensor based on the resonant micro-cantilever structure provided by the present invention forms a cantilever array arrangement, which can realize simultaneous measurement of multiple objects to be measured

7. The high-sensitivity biochemical sensor based on the resonant micro-cantilever structure provided by the present invention can adopt different driving methods, such as piezoelectric, electromagnetic or optical drive, etc., to realize portable applications.

Description of drawings

1 is a schematic structural view of a highly sensitive biochemical sensor based on a resonant micro-cantilever structure according to an embodiment of the present invention;

Figure 2 is a schematic cross-sectional view of the highly sensitive biochemical sensor based on the resonant micro-cantilever structure shown in Figure 1

Fig. 3 is a measurement schematic diagram of the Whist bridge detection circuit;

4 is a schematic diagram of a biochemical sensor array composed of two biochemical sensors shown in FIG. 1 after adsorbing biochemical molecules according to an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a biochemical sensor array composed of a plurality of biochemical sensors shown in Fig. 1 according to an embodiment of the present invention;

Explanation of reference signs:

1. Piezoresistive strip; 2. Signal transmission line; 3. Microcolumn structure; 4. Liquid storage tank; 5. Leakage hole; 6. Resonant cavity; 7.11. Output electrode; Molecular layers; 13. Biochemical molecules to be measured; 14. Reference beams.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The invention provides a high-sensitivity biochemical sensor based on a resonant micro-cantilever structure, which can measure biochemical molecules with high sensitivity and high precision by adopting a micro-cantilever structure with a micro-column structure 3, a liquid storage tank 4 and a liquid leakage hole 5 at the front end.

As shown in FIG. 1 , FIG. 1 is a schematic structural view of a highly sensitive biochemical sensor based on a resonant micro-cantilever structure according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of FIG. 1 . The single cantilever beam sensing device includes a resonant cavity, a cantilever beam and a Whist bridge detection circuit. Wherein the microcolumn structure 3 and the liquid storage tank 4 are etched at the front end of the cantilever beam, and the liquid leakage hole 5 flowing out of the biochemical solution is etched; the rear end of the cantilever beam is connected to the Whist bridge detection circuit, the The Whistler bridge detection circuit consists of four U-shaped piezoresistive strips 1, input electrodes 8, 9, 10 and output electrodes 7, 11, and the four piezoresistive strips 1 are connected to the input electrodes 8, 1 through signal transmission lines 2. 9, 10 and output electrodes 7, 11. In one embodiment of the present invention, electrode 9 is connected to the power signal, electrode 7 and electrode 11 are used as output electrodes, and electrode 8 and electrode 10 are grounded signals, thereby obtaining Whist bridge detection circuit.

The piezoresistive strip 1 at the rear end of the cantilever beam changes with the resonance amplitude of the cantilever beam, and the resistance change is converted into a voltage signal of the same frequency through a Whist bridge detection circuit. R ₁ is a piezoresistor, R ₂ , R ₃ , R ₄ is a fixed resistor, their initial resistance is the same as R, the change of piezoresistor after stress is ΔR, then the output signal is:

$\mathrm{<span\; class="notranslate">\; \&Delta;V</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="R"\; filenames="HDA00001884760400012.png"\; state="\{\{state\}\}">R</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="R"\; filenames="HDA00001884760400012.png"\; state="\{\{state\}\}">R</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span>}\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; R</span>}}\mathrm{<span\; class="notranslate">\; E.</span>}$

Through the signal transmission line 2 at the rear end of the piezoresistive strip, the output electrodes 7, 11 finally output the measurement signal. The frequency change of the cantilever beam is used to detect the biochemical molecule 13 adsorbed at the front end of the cantilever beam. The surface of the cantilever beam is modified with a detection monolayer structure 12 that can specifically respond to the molecules to be tested. After the molecules to be tested are adsorbed, their resonant frequency changes, and the biochemical molecules to be tested are characterized by detecting the resonant frequency. The resonant frequency of the beam fundamental mode is:

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}\sqrt{\frac{\mathrm{<span\; class="notranslate">\; k</span>}}{{\mathrm{<span\; class="notranslate">\; m</span>}}^{<span\; class="notranslate">\; *</span>}}}$

Among them, k is the stiffness coefficient of the beam, and m ^* is the effective mass of the beam.

If it is considered that its stiffness coefficient does not change with the applied load, the frequency shift can be expressed as

$\mathrm{<span\; class="notranslate">\; \&Delta;f</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; m</span>}}^{<span\; class="notranslate">\; *</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;m</span>}}^{<span\; class="notranslate">\; *</span>}$

Then the detectable mass of the cantilever beam varies with frequency as

${\mathrm{<span\; class="notranslate">\; \&Delta;m</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m</span>}}^{<span\; class="notranslate">\; *</span>}}{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}\mathrm{<span\; class="notranslate">\; \&Delta;\; f</span>}$

According to this principle, the adsorption mass of the biochemical molecule to be tested can be obtained.

In order to improve the ability to absorb characteristic molecules, the microcolumn structure 3 is etched at the front end of the cantilever beam to increase the effective area of the modification area at the front end of the beam, and a liquid storage tank 4 is made to fully react the biochemical molecules to be tested. At the same time, a flow hole 5 for the biochemical solution is made at the front end of the cantilever to avoid damage to the cantilever caused by the residue of the biochemical solution.

In order to ensure consistency, the four piezoresistive strips 1 in the Whistler bridge detection circuit are formed by ion implantation at the same time and adopt a "U"-shaped structure to better confine current.

In order to ensure that the signal output by the Whistler bridge detection circuit can meet the noise resolution problem of the external processing circuit, the minimum effective resistance of each piezoresistive strip 1 cannot be less than 1 kΩ.

The signal transmission lines 2 connecting the four piezoresistive strips 1 are formed by highly doped B ions, and isolation grooves are carved between the signal transmission lines to reduce the signal crosstalk between the signal transmission lines.

In practical applications, piezoelectric drive is used in the resonant working mode, and the resonant frequencies before and after the adsorption of biochemical molecules are measured respectively, and the mass of the adsorbed biochemical molecules is obtained through the difference between the two frequencies. It is obtained by measuring the frequency of the AC voltage signal between the output electrode 7 and the electrode 11 at the end of the detection circuit.

As shown in Figure 3, Figure 3 is a measurement schematic diagram of a Whist bridge detection circuit, in which the piezoresistive strip 1 at the root of the cantilever beam is equivalent to the _R4 resistance in the circuit, and the corresponding remaining three piezoresistive strips 1 are respectively R ₁ , R ₂ , R ₃ , and the four piezoresistive strips 1 have the same size and the same doping concentration of B ions, which ensures that their initial resistance values are all R.

In order to measure multiple biochemical molecules simultaneously, multiple biochemical sensors as shown in FIG. 1 are integrated to form a biochemical sensor array, and one of the biochemical sensors is selected as the reference beam 14 .

As shown in FIG. 4 , FIG. 4 is a schematic diagram of a biochemical sensor array composed of two biochemical sensors shown in FIG. 1 after adsorbing biochemical molecules according to an embodiment of the present invention. The surface of the cantilever beam of the biochemical sensor is modified with a detection monolayer structure 12 capable of specifically responding to the molecule 13 to be tested, and the adsorption of the molecule 13 to be tested changes the mass of the cantilever beam, which eventually leads to a change in the frequency of the cantilever beam. The mass of the biochemical molecule to be detected can be obtained by using the whist bridge detection circuit to detect the frequency change before and after the adsorption of the biochemical molecule.

As shown in Figure 5, Figure 5 is a schematic structural view of a biochemical sensor array composed of a plurality of biochemical sensors shown in Figure 1 according to an embodiment of the present invention, one biochemical sensor in the biochemical sensor array serves as a reference beam 14, and each of the other The surface of the cantilever beam of the biochemical sensor can be modified with a detection monolayer 12 that responds specifically to different molecules to be measured 13, and the array structure can simultaneously measure multiple biochemical molecules.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A highly sensitive biochemical sensor based on a resonant micro-cantilever beam structure, characterized in that the biochemical sensor comprises a resonant cavity, a cantilever beam and a Whist bridge detection circuit, wherein the free end of the cantilever beam is etched with a microcolumn structure (3) and a liquid storage tank (4), and are etched with leakage holes (5) for flowing out biochemical solutions; the supporting end of the cantilever beam is connected to the Whist bridge detection circuit, and the Whist bridge detection circuit The detection circuit is composed of four U-shaped piezoresistive strips (1), three input electrodes (8, 9, 10) and two output electrodes (7, 11), and the four piezoresistive strips (1) pass through the signal transmission line (2) Connected to input electrodes (8, 9, 10) and output electrodes (7, 11). 2. the highly sensitive biochemical sensor based on resonant micro-cantilever beam structure according to claim 1, is characterized in that, this biochemical sensor is to carry out highly sensitive detection to biochemical molecule by the frequency response of cantilever beam, and the surface modification of cantilever beam has The probe monolayer structure (12) that can specifically respond to the molecule to be tested changes the mass of the cantilever beam after adsorbing the molecule to be tested (13), which eventually leads to a change in the resonant frequency of the cantilever beam; using a Whist bridge detection circuit Detect the frequency change before and after adsorption of biochemical molecules to obtain the mass of biochemical molecules. 3. the highly sensitive biochemical sensor based on the resonant micro-cantilever beam structure according to claim 1, characterized in that, the liquid storage tank (4) is used for local modification and detection of monomolecular layers, reducing the absorption of large areas on the cantilever beam The frequency change due to the influence of the elastic constant. 4. The highly sensitive biochemical sensor based on the resonant micro-cantilever structure according to claim 1, characterized in that, the micro-column structure (3) is used to increase the adsorption area and improve the detection limit. 5. the highly sensitive biochemical sensor based on the resonant micro-cantilever beam structure according to claim 1, characterized in that, the leakage hole (5) is made in the liquid storage tank (4) to ensure that the liquid storage After the adsorption reaction in the tank is completed, the waste liquid is discharged from the through hole and does not remain in the cantilever beam. 6. The highly sensitive biochemical sensor based on the resonant micro-cantilever structure according to claim 1, wherein the driving mode of the cantilever is any one of piezoelectric, electrostatic, electromagnetic, thermoelectric or optical drive or Various. 7. the highly sensitive biochemical sensor based on the resonant micro-cantilever beam structure according to claim 1, is characterized in that, in this Whist bridge detection circuit, input electrode (9) connects power supply signal, output electrode (7, 11) As output electrodes, the electrical input electrodes (8, 10) are grounded signals. 8. the highly sensitive biochemical sensor based on resonant micro-cantilever beam structure according to claim 1, is characterized in that, one of the resistance in the described Whist bridge detection circuit is the U-shaped piezoresistive bar ( 1), the resonant frequency measurement of the cantilever beam is accomplished through the Whist bridge detection circuit, and the U-shaped piezoresistive strip (1) is used to improve the binding capacity of the current. 9. The highly sensitive biochemical sensor based on the resonant micro-cantilever beam structure according to claim 1, wherein the four piezoresistive strips (1) in the Whist bridge detection circuit are all "U" type Piezoresistive strips, four piezoresistive strips (1) are formed by ion implantation at the same time, which ensures the consistency of resistance to the greatest extent and effectively improves the measurement accuracy, and the effective resistance value of each piezoresistive strip (1) is greater than or equal to 1kΩ . 10. The highly sensitive biochemical sensor based on the resonant micro-cantilever beam structure according to claim 1, wherein an isolation groove structure is etched between the transmission lines of the Whist bridge detection circuit for reducing the transmission line The crosstalk between the signals ensures the measurement accuracy of the Whist bridge detection circuit.

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