Mass spectrum label probe for rapid drug sensitive test as well as preparation and application of mass spectrum label probe

Abstract

The invention belongs to the field of biological medicine, and particularly relates to a mass spectrum tag probe for a rapid drug sensitive test as well as preparation and application thereof, and the mass spectrum tag probe mainly comprises three parts, namely a gold nanoparticle carrier, a pegylated antibiotic target head and a mass spectrum tag peptide fragment. The probe disclosed by the invention is low in preparation cost, good in stability and high in detection speed (only 4 hours), and compared with a traditional drug sensitive test, the probe disclosed by the invention can be used for directly detecting a complex bacterial sample and does not need to be purified and cultured; compared with biosensing and mass spectrometry technologies, the probe provided by the invention has higher detection sensitivity and is not easily influenced by a matrix; compared with a qPCR technology, the method does not need to know the sequence information of the drug-resistant gene in advance, can directly detect the apparent sensitivity / drug resistance of bacteria, and is wider in detection range; compared with biosensing, mass spectrometry, qPCR and other methods, the probe provided by the invention can realize detection of various pathogenic bacteria and detection of sensitivity of multiple antibiotic drugs.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine, and specifically relates to a mass spectrometry label probe for rapid drug sensitivity testing and its preparation and application. Background Art

[0002] Bacterial infections are a major challenge to global public health. With the widespread use of antibiotics, bacterial resistance is becoming increasingly serious, posing significant challenges to clinical treatment. The World Health Organization (WHO) has identified antibiotic resistance as one of the top ten global public health threats, and estimates that by 2050, deaths from drug-resistant infections could surpass those from diseases like cancer, becoming one of the leading causes of death worldwide. Therefore, rapidly and accurately determining pathogens' sensitivity to antibiotics is crucial for effectively treating bacterial infections, reducing antibiotic overuse, and lowering mortality rates.

[0003] Although traditional drug sensitivity test methods, such as broth microdilution, paper diffusion, and agar dilution, are widely used in clinical practice, they have problems such as long detection time, complex operation, and highly subjective interpretation of results. These methods usually take 36-72 hours to produce results and cannot meet the needs of rapid clinical diagnosis. While waiting for drug sensitivity results, doctors often have to use broad-spectrum antibiotics empirically, which may not only lead to antibiotic abuse and further aggravate the problem of drug resistance, but also delay the best time for treatment, increasing the risk of death and medical costs for patients. Therefore, the development of rapid and accurate drug sensitivity test methods has become an urgent problem to be solved in the field of clinical microbiology.

[0004] Currently, commonly used rapid antimicrobial susceptibility testing methods include automated antimicrobial susceptibility testing systems, biosensor technology, real-time quantitative PCR (qPCR), and mass spectrometry. However, these technologies all have varying degrees of limitations in detecting bacterial antibiotic susceptibility. For example, while automated antimicrobial susceptibility testing systems have reduced testing time to a certain extent, they still require significant time due to the prior bacterial purification and culture. Rapid antimicrobial susceptibility testing methods based on biosensors and mass spectrometry face challenges in practical applications, including sample matrix effects, nonspecific binding, and low sensitivity. qPCR technology can only detect known resistance genes and may not detect emerging resistance mechanisms or unresearched resistance genes, limiting its detection range. Furthermore, while these three methods can achieve rapid antimicrobial susceptibility testing, their multi-target detection capabilities for multiple pathogens are limited, and they cannot simultaneously measure the susceptibility of pathogens to multiple antibiotics, limiting their multiplex detection capabilities. Therefore, it is necessary to develop rapid, multiplexed, and highly sensitive antimicrobial susceptibility testing methods to provide accurate treatment plans for bacterial infections as soon as possible. Summary of the Invention

[0005] In view of the shortcomings of the existing problems, the purpose of the present invention is to provide a mass spectrometry label probe for rapid drug sensitivity testing and its preparation and application.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] In a first aspect, the present invention provides a mass spectrometry label probe for rapid drug sensitivity testing, which mainly consists of three parts: a gold nanoparticle (GNP) carrier, a PEGylated antibiotic target head, and a mass spectrometry label peptide segment.

[0008] In a specific embodiment, the antibiotic is ampicillin, meropenem and / or ceftriaxone.

[0009] In a specific embodiment, the peptide segment is selected from any one of the following (A1)-(A3):

[0010] (A1) AVLGDPFRC, as shown in SEQ ID NO: 1;

[0011] (A2) AVVGVDPFRC, as shown in SEQ ID NO: 2;

[0012] (A3) AVLGVDPFRC, as shown in SEQ ID NO: 3.

[0013] In a more specific embodiment, the antibiotic and peptide segment in the mass spectrometry tag probe of the present invention can be selected as follows: when the antibiotic is ampicillin, the peptide segment is as shown in SEQ ID NO: 1;

[0014] When the antibiotic is meropenem, the peptide segment is as shown in SEQ ID NO: 2;

[0015] When the antibiotic is ceftriaxone, the peptide segment is as shown in SEQ ID NO: 3. In a more specific embodiment, the particle size of the gold nanoparticles is 13 nm.

[0016] In a specific embodiment, the molar ratio of the GNP, antibiotic, and peptide is 1:50-150:5000-8000.

[0017] In a specific embodiment, the molar ratio of the GNP, antibiotic, and peptide is 1:100:6000.

[0018] In a second aspect, the present invention provides a method for preparing the mass spectrometry label probe for rapid drug sensitivity testing as described above, the method comprising the following steps:

[0019] Step 1, preparing gold nanoparticles;

[0020] Step 2, preparation of PEGylated antibiotics: mixing the antibiotics with polyethylene glycol containing disulfide bonds in DMSO at a molar ratio of 2:1, protecting from light, reacting at room temperature, and purifying to obtain PEGylated antibiotics;

[0021] Step 3, preparation of mass spectrometry label probe: Mix the gold nanoparticles from step 1 with the PEGylated antibiotic from step 2, add potassium carbonate solution, protect from light, and react at room temperature for 10±3 hours; add the mass spectrometry label peptide and continue the reaction for 12±5 hours. Centrifuge the reaction solution and wash to obtain the mass spectrometry label probe.

[0022] In a specific embodiment, the reaction time of step 2 is 12±5 hours.

[0023] In a specific embodiment, the gold nanoparticles can be prepared by themselves or purchased commercially.

[0024] The present invention provides a method for preparing gold nanoparticles, but the invention is not limited thereto. The method for preparing the gold nanoparticles is as follows: first, boiling an aqueous solution of tetrachloroauric acid, then adding an aqueous solution of sodium citrate, stirring and boiling, and continuing the heating reaction. Next, removing the heat source, and continuing the stirring reaction to obtain gold nanoparticles (GNPs).

[0025] In a more specific embodiment, the concentration of the aqueous solution of tetrachloroauric acid is 1.00 mM.

[0026] In a specific embodiment, the concentration of the sodium citrate aqueous solution is 38.8 mM. In a specific embodiment, the antibiotic is ampicillin, meropenem and / or ceftriaxone.

[0027] In a specific embodiment, the peptide segment is selected from any one of the following (A1)-(A3):

[0028] (A1) AVLGDPFRC, as shown in SEQ ID NO: 1;

[0029] (A2) AVVGVDPFRC, as shown in SEQ ID NO: 2;

[0030] (A3) AVLGVDPFRC, as shown in SEQ ID NO: 3.

[0031] In a third aspect, the present invention provides a kit comprising the mass spectrometry label probe described above.

[0032] In a fourth aspect, the present invention provides use of the mass spectrometry label probe and the kit described above in the preparation of a product for detecting bacterial infection.

[0033] In a specific embodiment, the detection of bacterial infection is performed by using the mass spectrometry tag probe and the kit described above to perform drug sensitivity testing.

[0034] In a fifth aspect, the present invention protects a method for rapid drug sensitivity testing for purposes other than disease diagnosis and treatment, the method comprising the following steps:

[0035] (1) mixing and incubating the mass spectrometry label probe described above with the sample to be tested;

[0036] (2) Mass spectrometry is used to detect the released mass spectrometry-labeled peptides and analyze the sensitivity of bacteria to antibiotics.

[0037] In a specific embodiment, the release time of the mass spectrometry tag peptide is 20 minutes.

[0038] Beneficial effects

[0039] The mass spectrometry label probe for rapid drug sensitivity testing provided by the present invention, as well as its preparation and application, has the following beneficial effects compared with the prior art:

[0040] (1) The probe of the present invention has low preparation cost, good stability, and fast detection speed (only 4 hours);

[0041] (2) Compared with traditional drug susceptibility testing, the probes of the present invention can directly detect complex bacterial samples without purification and cultivation;

[0042] (3) Compared with biosensing and mass spectrometry technologies, the probe of the present invention has higher detection sensitivity and is less susceptible to matrix influence;

[0043] (4) Compared with qPCR technology, the present invention does not require the sequence information of the drug-resistant gene in advance, and can directly detect the apparent sensitivity / resistance of bacteria, with a wider detection range;

[0044] (5) Compared with biosensing, mass spectrometry, and qPCR methods, the probes described in the present invention can detect multiple pathogens and multiple antibiotic susceptibility tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the synthesis of mass spectrometry tag probes (A) and the process of bacterial detection (B).

[0046] Figure 2 UV spectrum (A), particle size distribution (B) and TEM characterization (C) of GNPs.

[0047] Figure 3 Synthetic routes of the PEGylated antibiotics Amp-PEG (A), Mer-PEG (B), and Cef-PEG (C).

[0048] Figure 4 Mass spectra of Amp-PEG (A), Mer-PEG (B), and Cef-PEG (C).

[0049] Figure 5 Hydrodynamic particle size and zeta potential of three mass spectrometry tag probes before and after synthesis.

[0050] Figure 6 Optimization of the ratio of antibiotics to peptides on the mass spectrometry tag probe.

[0051] Figure 7 Stability assessment of mass spectrometry tag probes.

[0052] Figure 8 Specificity evaluation of mass spectrometry tag probes.

[0053] Figure 9 Optimization of release time of tagged peptides.

[0054] Figure 10 Sensitivity evaluation of mass spectrometry tag probes.

[0055] Figure 11 Detection results of the probe set against four strains of Escherichia coli.

[0056] Figure 12 Results of disk diffusion susceptibility testing of four Escherichia coli strains to three antibiotics.

[0057] Figure 13 Detection results of the probe set on 10 clinical samples. DETAILED DESCRIPTION

[0058] The present invention is further described in detail below with reference to the examples. Reagents or instruments used without manufacturer's indication are considered to be conventional products that can be purchased on the market.

[0059] like Figure 1 As shown in A, the mass spectrometry tag probe of the present invention consists of three parts: a gold nanoparticle (GNP) carrier, a PEGylated antibiotic target head and a mass spectrometry tag peptide segment.

[0060] Gold nanoparticles are selected as signal amplification carriers in the present invention due to their strong loading capacity, easy surface modification, and simple synthesis steps.

[0061] The present invention uses three commonly used antibiotics: ampicillin, meropenem, and ceftriaxone, as target recognition moieties to specifically identify their corresponding sensitive bacteria. First, disulfide-bonded polyethylene glycol (PEG) is covalently modified onto each of the three antibiotics via an amidation reaction to form PEGylated antibiotic heads. The PEGylated antibiotic heads are then reacted with GNPs, breaking the disulfide bonds on the PEG and forming Au-S bonds with the GNPs, thereby attaching the PEGylated antibiotic heads to the GNP surface.

[0062] The present invention utilizes three peptides: AVLGDPFRC, AVVGVDPFRC, and AVLGVDPFRC, as mass spectrometry tag molecules. The carboxyl termini of these three peptides all contain cysteine ​​residues containing thiol groups, which can directly react with GNPs to form Au-S, effectively modifying the peptides onto the GNP surface. Furthermore, organisms in the natural environment cannot independently synthesize these three peptides, so their absence in samples effectively eliminates biological background effects. The three peptides were reacted with PEGylated antibiotic-modified GNPs to produce three mass spectrometry tag probes: ampicillin probe (A probe), meropenem probe (M probe), and ceftriaxone probe (C probe) (Table 1). The thiol groups on reduced glutathione (GSH) compete with Au for binding, breaking the original Au-S residues and releasing the tagged peptides from the GNP surface. Furthermore, GSH has good biocompatibility and is non-irritating to bacteria, hence its selection as the release agent for the tagged peptides. During the incubation of the mass spectrometry label probe with bacteria, the antibiotic target head on the probe can bind to the PBPs on the bacterial membrane and then release the label peptide under the action of excess GSH. Subsequently, the released label peptide is quantitatively detected by mass spectrometry, which can convert the amount of antibiotic bound to the bacterial surface into the mass response of the label peptide and amplify it ( Figure 1 B) This method helps to achieve rapid drug susceptibility testing and select antibiotics with the best therapeutic effect as early as possible.

[0063] Table 1 Composition of three mass spectrometry label probes

[0064]

[0065] Preferred embodiments of the present invention are described below by way of example, but the present invention is not limited thereto.

[0066] Example 1 Preparation and characterization of probe sets

[0067] (1) Preparation of gold nanoparticles (GNPs)

[0068] The GNPs used in this technical solution have a particle size of 13 nm. This particle size has the best stability in the colloidal state. First, 50 ml of a 1.00 mM aqueous solution of tetrachloroauric acid was boiled, and then 5 ml of a 38.8 mM aqueous solution of sodium citrate was added. The mixture was further stirred and boiled, and the heating reaction was continued for 10 minutes. Then, the heat source was removed and the reaction was continued with stirring for 15 minutes to obtain GNPs. The obtained GNPs were characterized by UV, Zetasizer, and TEM. The results are as follows: Figure 2 As shown in the figure, the maximum UV absorption wavelength of GNPs is 520nm, the hydrodynamic particle size is concentrated in the range of 13-14nm, and TEM observations show that GNPs are spherical and 13nm in size. These results confirm that the synthesis of GNPs with a particle size of 13nm was successful.

[0069] (2) Preparation of PEGylated antibiotics

[0070] Three antibiotics (ampicillin, meropenem and ceftriaxone) were mixed with PEG containing disulfide bonds (NHS-PEG-SS-PEG-NHS) in DMSO (5 ml) at a molar ratio of 2:1 (10 mM:5 mM), protected from light, and gently shaken at room temperature for 12 hours ( Figure 3 The reaction products were then purified using a dialysis bag with a molecular weight cutoff of 1000 Da to obtain three PEGylated antibiotics (Amp-PEG, Mer-PEG, and Cef-PEG). The mass spectrometry characterization results are shown in Figure 2. Figure 4 As shown, the molecular weights of the three PEGylated antibiotics were consistent with the theoretical values, which confirmed the successful synthesis of the PEGylated antibiotics.

[0071] (3) Preparation of mass spectrometry label probe sets

[0072] First, 10 ml of 10 nM GNPs was mixed with 200 μl of 50 μM PEGylated antibiotics. 200 μl of 63 mM potassium carbonate solution was added and the mixture was incubated for 10 hours at room temperature with gentle shaking in the dark. Then, 120 μl of 5 mM labeled peptide was added and the reaction continued for 12 hours. Finally, the reaction solution was centrifuged at 10,000 rpm for 15 minutes and washed three times with deionized water to obtain mass spectrometry labeled probes (A probe, M probe, and C probe).

[0073] like Figure 5As shown, the hydrodynamic particle size of the three mass spectrometry tag probes increased compared with GNPs, while the absolute value of the zeta potential decreased. The increase in particle size was mainly due to the surface modification of PEGylated antibiotics and tag peptides, which increased the hydration radius of GNPs. In addition, PEGylated antibiotics and tag peptides gradually reduced the surface charge of GNPs. This is because the amino groups on the antibiotics and peptides are positively charged, neutralizing the negative charge on the GNP surface. The changes in hydrodynamic particle size and zeta potential indicate that the three mass spectrometry tag probes were successfully synthesized. Subsequently, the ratio of antibiotics and peptides in each mass spectrometry tag probe was optimized, and the results showed that the optimal molar ratio was GNP / antibiotic / peptide = 1 / 100 / 6000 ( Figure 6 ), so that the mass spectrometry tag probe carries as many tag peptides as possible to achieve the most efficient signal amplification while identifying sensitive bacteria.

[0074] Example 2 Stability and specificity of probe sets

[0075] (1) Stability of probe set

[0076] In order to evaluate the reliability of the three mass spectrometry tag probes in actual detection applications, a stability evaluation was conducted. The experimental results showed that the three mass spectrometry tag probes showed good stability within one month. Three different batches of each mass spectrometry tag probe were stored at 4°C for one month, and the binding ability of the probes with different storage times to bacteria was tested to evaluate the stability of the mass spectrometry tag probes. Figure 7 As shown in the figure, within one month of storage, the binding ability of the three mass spectrometry label probes to bacteria remained stable, indicating that the synthesized probe set has good stability, providing reliable guarantee for its actual detection in bacterial samples.

[0077] (2) Specificity of probe set

[0078] In order to shorten the time of rapid drug susceptibility testing and avoid potential interference from other substances, mass spectrometry label probes need to have recognition specificity for target bacteria. Two experiments were designed to evaluate the specificity of three mass spectrometry label probes in bacterial detection. Figure 8 As shown in Figures AC, three types of nanoparticles, GNP-peptide, PEG-GNP-peptide, and antibiotic-PEG-GNP-peptide, were incubated with sensitive Escherichia coli ATCC 25922. Only when the GNP surface was modified with a PEGylated antibiotic recognition target head could the binding of the nanoparticles to the bacteria be detected, indicating that the PEGylated antibiotic target head is the key to identifying bacteria. Figure 8D shows that when the three mass spectrometry-labeled probes were incubated with sensitive E. coli (ATCC 25922 and BW 25113) and resistant E. coli (ATCC 35218 and Bio 133826), the three probes bound significantly more to the two sensitive strains than to the two resistant strains. These experimental results demonstrate that the synthesized probe set can recognize and bind to target bacteria with high specificity and exhibits excellent anti-interference capabilities, providing strong support for its use in bacterial detection in complex environments.

[0079] Example 3 Rapid drug sensitivity test based on probe set

[0080] After the probe set recognizes bacteria, the labeled peptide needs to be released quickly and completely from the GNP surface to shorten the detection time and achieve effective signal amplification. The time for GSH to release the labeled peptide was optimized, and the release efficiency of the labeled peptide at different incubation times was detected by LC. When the probe set was incubated with excess GSH for 20 minutes, the peptide release efficiency was about 95% and reached a growth plateau ( Figure 9 ), indicating that the optimal release time of the tagged peptide is 20 minutes. The entire detection process can be completed quickly within 4 hours.

[0081] The three mass spectrometry label probes were mixed in equal amounts and then incubated with bacteria of different concentrations. The number of the three mass spectrometry label probes bound to the bacteria was detected by LC-MS / MS to explore the lowest bacterial concentration that this method can detect and thus evaluate the sensitivity of the probes. Figure 10 As shown in the figure, the invented mass spectrometry tag probe can detect a minimum of 10 CFU / ml of bacterial solution and can clearly distinguish the number of bacteria bound by the three mass spectrometry tag probes, indicating that the mass spectrometry tag probe has good detection sensitivity. The minimum bacterial concentration required for traditional drug sensitivity testing is usually about 5×10 5 CFU / ml, so the signal amplification of this probe set can reach 50,000 times, and the sensitivity of bacteria to multiple antibiotics can be detected without bacterial culture, realizing rapid, multiplex, and high-sensitivity detection.

[0082] Table 2 Comparison between mass spectrometry probe method and disc diffusion method

[0083]

[0084]

[0085] The actual performance of the rapid drug susceptibility test based on this probe set in bacterial detection was evaluated by selecting Escherichia coli strains (ATCC 25922, BW 25113) that do not express β-lactamase as positive controls and Escherichia coli strains that express β-lactamase (ATCC 35218, Bio 133826) as negative controls. At the same time, the reliability of the results of this test method was verified by using the disk diffusion method, one of the traditional drug susceptibility test methods. Figure 11 As shown, the sensitivity of E. coli ATCC 25922 and BW25113 to the three antibiotics was ampicillin < meropenem < ceftriaxone. The sensitivity of E. coli ATCC 35218 in the negative control group to the three antibiotics was ampicillin < ceftriaxone < meropenem, while the sensitivity of E. coli Bio 133826 to the three antibiotics was ampicillin < meropenem < ceftriaxone. Almost no A probe was detected in the negative control group, that is, the two bacteria in the negative control group were resistant to ampicillin. The above test results are consistent with the results of the traditional disk diffusion method ( Figure 12 ), demonstrating the high reliability of this method and its applicability to rapid drug susceptibility testing. Compared with the traditional disk diffusion method, this method offers advantages such as shorter detection time, lower detection limits, and the ability to perform multiplex detection (Table 2).

[0086] Example 4 Clinical sample detection

[0087] In order to verify the practicality of the invented mass spectrometry label probe set in clinical sample detection, drug sensitivity testing was performed on 10 clinical blood samples using this probe set. Blood samples were collected from 5 patients with sepsis and 5 patients with Escherichia coli sepsis (Table 3), with 2 ml of each sample. The blood samples were centrifuged at 1000 rpm for 3 minutes at 4°C, and the supernatant was retained to remove impurities such as blood cells. The supernatant was then centrifuged at 12000 rpm for 8 minutes at 4°C, and the precipitate was retained and discarded. The precipitate was further resuspended with physiological saline to obtain a bacterial suspension. The bacterial suspension was mixed and incubated with this mass spectrometry label probe set, and the number of three mass spectrometry label probes bound to the bacteria was detected by LC-MS / MS to determine the sensitivity of bacteria in clinical samples to the three antibiotics.

[0088] Table 3 Sources of clinical blood samples

[0089]

[0090]

[0091] Test results such as Figure 13As shown, bacterial susceptibility to the three antibiotics varied among the 10 clinical samples. The bacterial susceptibility of patients 1, 2, 4, 7, 8, and 10 to the three antibiotics ranked ampicillin < meropenem < ceftriaxone. The bacterial susceptibility of patients 5 and 9 ranked ampicillin < ceftriaxone < meropenem. In contrast, the bacterial susceptibility of patients 3 and 6 to meropenem and ceftriaxone was similar, with lower susceptibility to ampicillin. Across all samples, bacteria showed high susceptibility to meropenem and ceftriaxone, but relatively low susceptibility to ampicillin. This is consistent with clinical experience that ampicillin is more susceptible to resistance. It is recommended that patients 1, 2, 3, 4, 6, 7, 8, and 10 be treated with ceftriaxone first, while patients 5 and 9 should be treated with meropenem first. The above results verify the practicality of this probe set in clinical sample detection and provide strong support for the rapid and accurate diagnosis and treatment of bacterial infectious diseases such as sepsis.

[0092] The protection content of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be thought of by those skilled in the art are included in the present invention and are protected by the appended claims.

Claims

1. A mass spectrometry label probe for rapid drug sensitivity testing, characterized in that: The mass spectrometry label probe mainly consists of three parts: a gold nanoparticle carrier, a PEGylated antibiotic target head and a mass spectrometry label peptide segment.

2. The mass spectrometry label probe according to claim 1, characterized in that The antibiotics are ampicillin, meropenem and / or ceftriaxone.

3. The mass spectrometry label probe according to claim 1, characterized in that The peptide segment is selected from any one of the following (A1)-(A3): (A1) AVLGDPFRC, as shown in SEQ ID NO: 1; (A2) AVVGVDPFRC, as shown in SEQ ID NO: 2; (A3) AVLGVDPFRC, as shown in SEQ ID NO: 3; Preferably, When the antibiotic is ampicillin, the peptide segment is as shown in SEQ ID NO: 1; When the antibiotic is meropenem, the peptide segment is as shown in SEQ ID NO: 2; When the antibiotic is ceftriaxone, the peptide segment is shown as SEQ ID NO:

3.

4. The mass spectrometry label probe according to claim 1, characterized in that The molar ratio of the GNP, antibiotic, and peptide is 1:50-150:5000-8000; Preferably, the molar ratio of the GNP, antibiotic, and peptide is 1:100:6000.

5. The mass spectrometry label probe according to claim 1, characterized in that The particle size of the gold nanoparticles is 13 nm.

6. The method for preparing a mass spectrometry-labeled probe for rapid drug sensitivity testing according to claim 1, comprising the following specific steps: Step 1, preparing gold nanoparticles; Step 2, preparation of PEGylated antibiotics: mixing the antibiotics with polyethylene glycol containing disulfide bonds in DMSO at a molar ratio of 2:1, protecting from light, reacting at room temperature for 12±5 hours, and purifying to obtain PEGylated antibiotics; Step 3, preparation of mass spectrometry label probe: Mix the gold nanoparticles from step 1 with the PEGylated antibiotic from step 2, add potassium carbonate solution, protect from light, and react at room temperature for 10±3 hours; add the mass spectrometry label peptide and continue the reaction for 12±5 hours. Centrifuge the reaction solution and wash to obtain the mass spectrometry label probe.

7. The method according to claim 6, characterized in that The antibiotics are ampicillin, meropenem and / or ceftriaxone; Preferably, the peptide segment is selected from any one of the following (A1)-(A3): (A1) AVLGDPFRC, as shown in SEQ ID NO: 1; (A2) AVVGVDPFRC, as shown in SEQ ID NO: 2; (A3) AVLGVDPFRC, as shown in SEQ ID NO:

3.

8. A kit, characterized in that The kit contains the mass spectrometry tag probe according to claim 1.

9. Use of the mass spectrometry label probe according to claim 1 or the kit according to claim 8 in the preparation of a product for detecting bacterial infection.

10. A method for rapid drug sensitivity testing for purposes other than disease diagnosis and treatment, characterized in that: The following steps are involved: (1) mixing and incubating the mass spectrometry label probe according to claim 1 with a sample to be tested; (2) Using mass spectrometry to detect the released mass spectrometry-labeled peptides, the sensitivity of bacteria to antibiotics was analyzed; Preferably, the release time of the mass spectrometry tag peptide is 20 minutes.

Images