Textile dyeing and finishing auxiliary micro-detection method based on microfluidic intelligent sensor

Abstract

The present application relates to a microfluidic intelligent sensor-based textile dyeing and finishing agent micro-detection method, comprising: making the sensor sampling end and the textile to be detected adhere to form a closed sampling area, adding an extraction solution to the closed sampling area, and recovering a sample solution containing the dyeing and finishing agent to be detected; introducing the sample solution into a microfluidic chip and dividing it into a first liquid stream and a second liquid stream, making the first liquid stream directly enter a detection area to obtain a first detection response, and making the second liquid stream first pass through a treatment area provided with an agent response weakening material and then enter the detection area to obtain a second detection response; and obtaining the detection result of the dyeing and finishing agent to be detected in the textile to be detected according to the response difference, response ratio or response decay rate between the two detection responses. The method can form two types of response channels, i.e., unweakened and weakened, in the same sample solution, improve the selectivity, sensitivity and anti-interference ability of micro-detection under a complex dyeing and finishing agent system, and improve the adaptability to different types of dyeing and finishing agents and different sensing response modes.

Description

Technical Field

[0001] This invention relates to the field of textile dyeing and finishing auxiliary agent detection technology, specifically a method for trace detection of textile dyeing and finishing auxiliary agents based on microfluidic intelligent sensors. Background Technology

[0002] In existing technologies, a wide variety of leveling agents, dispersants, softeners, refining and degreasing agents, soaping agents, adhesives, and silicone oil-based finishing auxiliaries are used in textile dyeing and finishing processes. Their residual state, migration state, and trace adhesion state directly affect the dyeing and finishing quality, hand feel, ecological safety, and subsequent quality assessment of textiles. Because dyeing and finishing auxiliaries usually contain surface-active components, solvent components, or reactive functional components, and are unevenly distributed on the fiber surface, between fibers, and in the finishing film layer, conventional whole-piece sampling, extraction, centrifugation, filtration, chromatography, or spectroscopic detection methods often require large sample volumes and long pretreatment times, making it difficult to obtain stable and comparable test results in scenarios involving small areas, trace residues, or rapid on-site assessment.

[0003] Patent application CN109444295A discloses a method for determining the content of eight prohibited and restricted ethylene glycol ether solvents in textile dyeing and finishing auxiliaries. It employs ultrasonic solvent extraction, solid-phase extraction purification, and GC / MS selected ion monitoring mode to achieve simultaneous determination of multiple ethylene glycol ether organic solvents. This method can improve sensitivity and anti-interference ability, but it is still mainly aimed at auxiliary raw solutions or sample solutions after pretreatment. The detection process relies on extraction, purification, and large-scale instrument analysis, which is not convenient for direct, rapid, and in-situ detection of local residues on the fabric surface. Patent application CN113295639A discloses a method for testing the high-temperature dispersibility of leveling agents for disperse dyes. This method involves preparing a dye liquor, heating and holding it at that temperature, cooling and filtering, dissolving residual dye on filter paper with an organic solvent, and then quantitatively analyzing the high-temperature dispersibility of the leveling agent using a UV spectrophotometer. This approach improves quantification and repeatability compared to traditional qualitative evaluation based on filter paper color. However, its focus is on evaluating the dispersibility of the leveling agent in the dye liquor system, still requiring simulated dyeing conditions and offline processing steps. It cannot effectively address the problems of weak response, strong background interference, difficulty in repeatedly obtaining local samples, and fluctuations in results due to differences in the sensor interface between different batches of textiles with trace amounts of dyeing and finishing auxiliaries in complex matrices. Therefore, it is necessary to provide a detection method that can perform trace extraction on local areas of textiles under closed sampling conditions and obtain differentiated detection signals using microfluidic splitting and response attenuation control mechanisms to improve the on-site adaptability, anti-interference ability, and reliability of trace detection of textile dyeing and finishing auxiliaries. Summary of the Invention

[0004] The purpose of this invention is to provide a method for detecting trace amounts of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors, thereby addressing some of the drawbacks and shortcomings pointed out in the background art.

[0005] The present invention adopts the following technical solution to solve the above-mentioned technical problems:

[0006] The sensor sampling end is attached to the textile to be tested to form a closed sampling area. An extraction solution is added to the closed sampling area to recover the sample solution containing the dyeing and finishing auxiliary agent to be tested.

[0007] The sample solution is introduced into the microfluidic chip and divided into a first liquid flow and a second liquid flow. The first liquid flow directly enters the detection area and obtains a first detection response in the detection area. The second liquid flow first passes through a treatment area equipped with an auxiliary agent response weakening material and then enters the detection area to obtain a second detection response. The auxiliary agent response weakening material is used to adsorb, bind, consume or shield the dyeing and finishing auxiliary to be tested, so as to reduce the electrochemical response, impedance response, optical response, wetting response or reaction response of the dyeing and finishing auxiliary to be tested in subsequent detection.

[0008] The detection results of the dyeing and finishing auxiliary agent in the textile to be tested are obtained based on the response difference, response ratio, or response decay rate between the first detection response and the second detection response.

[0009] Furthermore, the first liquid flow and the second liquid flow are separated by a carrier liquid and then enter the same detection area in sequence, so that the first detection response and the second detection response are formed at the same sensing interface.

[0010] Furthermore, the treatment zone is provided with a surface activity weakening section and a reactivity weakening section along the second liquid flow direction, so that the surface activity and the ability of the dyeing and finishing auxiliary agent to be tested in the second liquid flow are reduced sequentially.

[0011] Furthermore, after obtaining the second detection response, a release liquid is reverse-flowed into the processing area, allowing the dyeing and finishing auxiliary agent to be tested, which was adsorbed, bound, or retained by the auxiliary agent response-weakening material, to enter the detection area and generate a third detection response.

[0012] Furthermore, the surface activity weakening section is provided with alternating hydrophilic and hydrophobic regions, so that the second liquid flow undergoes liquid front pinning and re-release when passing through the surface activity weakening section, thereby reducing the influence of the dyeing and finishing auxiliary agent to be tested on the subsequent wetting response.

[0013] Furthermore, the reactive activity weakening section is equipped with consumable reactive groups, so that the second liquid flow after passing through the reactive activity weakening section comes into contact with the consumable reactive groups, thereby reducing the reaction response of the dyeing and finishing auxiliary to be tested in the detection area.

[0014] Furthermore, an isolation liquid section is provided between the surface activity weakening section and the reactivity weakening section, so that the liquid leading edge of the second liquid after passing through the surface activity weakening section is separated from the subsequent liquid before entering the reactivity weakening section.

[0015] Furthermore, the release liquid is introduced into the treatment zone in a reverse pulse manner, and the flow rate of adjacent pulses increases according to a preset gradient, so that the dyeing and finishing auxiliaries to be tested, which have different binding strengths with the auxiliary response weakening material, are released sequentially, and the third detection response can be distinguished within different time windows.

[0016] Furthermore, the processing area is provided with at least two auxiliary response weakening regions containing the auxiliary response weakening material and having different binding strengths. When the release liquid flows in reverse through each auxiliary response weakening region, the dyeing and finishing auxiliary to be tested enters the detection area in the release order corresponding to the binding strength and generates the third detection response.

[0017] Furthermore, a holding liquid is introduced between two adjacent pulses of the release liquid. The holding liquid is used to maintain the continuity of the flow path from the treatment area to the detection area and to allow the dyeing and finishing auxiliary to be tested released in the previous pulse to first enter the detection area to generate the third detection response, and then the dyeing and finishing auxiliary to be tested with a higher binding strength is released by the next pulse.

[0018] This invention achieves localized, micro-scale, and relatively closed sampling without extensive damage to the textile being tested by attaching the sensor sampling end to the textile to be tested. It also reduces the impact of external environment, sampling location diffusion, and human transfer processes on the test results, thereby improving the consistency of sample acquisition and the convenience of testing operations.

[0019] This invention introduces a sample solution into a microfluidic chip, which then splits it into a first flow and a second flow. The first flow directly enters the detection zone to obtain a first detection response, while the second flow passes through a treatment zone containing a material that attenuates the response of the auxiliary agent before entering the detection zone to obtain a second detection response. The detection result is obtained based on the difference in response, the ratio of response, or the response attenuation rate between the two flows. Thus, the second flow can serve as a control flow after attenuation treatment, offsetting non-target responses caused by the fabric matrix, extract background, environmental fluctuations, and differences in the sensor interface state. This allows the detection result to better reflect the response contribution of the dyeing and finishing auxiliary agent itself.

[0020] The auxiliary agent response-weakening material in this invention can be used to adsorb, bind, consume, or shield the dyeing and finishing auxiliary agent to be tested, thereby reducing its electrochemical response, impedance response, optical response, wetting response, or reaction response in subsequent detection. This allows the same sample to form two types of response channels within the microfluidic system: unweakened and weakened. This design is beneficial for improving the selectivity, sensitivity, and anti-interference ability of trace detection in complex dyeing and finishing auxiliary agent systems, and for improving the adaptability of the detection method to different types of dyeing and finishing auxiliary agents and different sensing response modes. Attached Figure Description

[0021] Figure 1 This is a schematic flowchart of the method for detecting trace amounts of textile dyeing and finishing auxiliaries according to the present invention.

[0022] Figure 2 This is a flowchart of the microfluidic diversion and detection process in the same detection area in Embodiment 1 of the present invention.

[0023] Figure 3 This is a time-series isolation response diagram of the same detection area in Embodiment 1 of the present invention.

[0024] Figure 4 This is a conversion diagram of response decay rate and residual amount in Embodiment 1 of the present invention.

[0025] Figure 5 This is a flowchart of the reverse pulse release and multiple weakening regions in Embodiment 2 of the present invention.

[0026] Figure 6 This is a time window diagram of the third detection response pulse in Embodiment 2 of the present invention.

[0027] Figure 7 This is a graph showing the percentage of graded release and the determination of the confirmation value in Embodiment 2 of the present invention. Detailed Implementation

[0028] As attached Figure 1As shown, this embodiment provides a method for trace detection of textile dyeing and finishing auxiliaries based on a microfluidic smart sensor. During detection, the sensor sampling end is attached to the test area of ​​the textile to be tested, forming a closed sampling area between the sensor sampling end and the textile. An extraction solution is then added to the closed sampling area, ensuring sufficient contact between the extract and the dyeing and finishing auxiliaries on the surface of the textile. The liquid containing the dyeing and finishing auxiliaries is recovered as the sample solution. After the sample solution is introduced into the microfluidic chip, it is divided into a first liquid flow and a second liquid flow through a flow channel within the chip. The first liquid flow enters the detection area directly without undergoing response attenuation treatment and contacts the sensing interface, thereby obtaining a first detection response. The second liquid flow first flows through a treatment area containing an auxiliary response attenuation material before entering the detection area and contacting the sensing interface, thereby obtaining a second detection response. The auxiliary response attenuation material can adsorb, bind, consume, or shield the dyeing and finishing auxiliaries to be tested, thereby reducing the electrochemical response, impedance response, optical response, wetting response, or reaction response of the dyeing and finishing auxiliaries to be tested in subsequent detection. By comparing the response difference, response ratio, or response decay rate between the first and second detection responses, the interference of the textile substrate and sample liquid background on the detection results can be eliminated, and the detection results of the dyeing and finishing auxiliaries to be tested in the textile can be obtained.

[0029] The dyeing and finishing auxiliary agent to be tested can be one or more of the following: surfactants, softeners, fixing agents, leveling agents, dispersants, soaping agents, penetrants, chelating agents, or anti-wrinkle finishing agents that remain or adhere to the surface of textiles during the dyeing and finishing process. The extraction solution can be deionized water, an alcohol-containing aqueous solution, a buffer solution, or an aqueous liquid capable of wetting the textile and dissolving the dyeing and finishing auxiliary agent. The sensor sampling end can include a ring-shaped or frame-shaped sealing part, an inlet channel, and a return channel. The sealing part forms a closed sampling area after being fitted to the area to be tested. The extraction solution enters the closed sampling area through the inlet channel and is recovered as a sample solution through the return channel. The sensing interface can be an electrode sensing interface, an optical recognition interface, a wetting recognition interface, or a reaction recognition interface. The first detection response, the second detection response, and the third detection response can be changes in current, impedance, color, fluorescence, wetting state, flow state, or reaction signal, respectively. The auxiliary agent response-weakening material can be a porous adsorbent, ion exchange material, complexing material, molecular recognition material, immobilized reactive group material, or a combination thereof, as long as it can reduce the detection response of the dyeing and finishing auxiliary agent to be tested before entering the detection zone. The detection results can be obtained by pre-establishing the correspondence between the response difference and the content or residual level of the dyeing and finishing auxiliary agent to be tested, or by comparing it with a preset threshold range.

[0030] The first and second liquid streams are detected in the same detection zone. To prevent mixing when the two streams enter the detection zone, a carrier liquid can be introduced between the first and second streams, allowing them to enter the detection zone sequentially in a predetermined order. The carrier liquid can be a blank extract, buffer solution, or inert carrier liquid that is compatible with the sample solution and does not produce a significant detection response at the sensing interface. After entering the detection zone, the first stream contacts the sensing interface and forms a first detection response. Subsequently, the carrier liquid isolates and pushes away any residual sample solution in the detection zone. The second stream then enters the same detection zone and contacts the same sensing interface to form a second detection response. Because the first and second detection responses are formed at the same sensing interface, the impact of preparation differences, sensitivity differences, and background drift between different detection interfaces on the detection results can be reduced, improving the accuracy of the difference judgment between the first and second detection responses.

[0031] The treatment zone is sequentially configured with a surface activity attenuation section and a reactivity attenuation section along the flow direction of the second liquid stream. Upon entering the treatment zone, the second liquid stream first passes through the surface activity attenuation section, weakening the surface activity of the dyeing and finishing auxiliary agent being tested and thus reducing its influence on the subsequent wetting response. Subsequently, the second liquid stream enters the reactivity attenuation section, further reducing the ability of the dyeing and finishing auxiliary agent to participate in the detection reaction, thereby minimizing its reaction response in the detection zone. By sequentially attenuating surface activity and reactivity along the flow direction, a identifiable attenuation of the second detection response relative to the first detection response can be achieved, facilitating the subsequent determination of the detection results of the dyeing and finishing auxiliary agent based on the response difference.

[0032] After obtaining the second detection response, a release solution is introduced into the processing zone in the reverse direction. The release solution flows through the auxiliary response-weakening material in the opposite direction to the second flow entering the processing zone, causing the analyte dyeing and finishing auxiliary adsorbed, bound, or trapped by the auxiliary response-weakening material to be released from the processing zone and enter the detection zone with the release solution. The release solution can be a buffer solution, salt solution, alcohol-based aqueous solution, or eluent that can reduce the interaction strength between the analyte dyeing and finishing auxiliary and the auxiliary response-weakening material, and the release solution should not generate a background response that is difficult to distinguish from the analyte dyeing and finishing auxiliary when entering the detection zone. The released analyte dyeing and finishing auxiliary generates a third detection response after contacting the sensing interface in the detection zone. This third detection response allows for further confirmation of the analyte dyeing and finishing auxiliary weakened or trapped in the second flow by the processing zone, thereby improving the reliability of the detection results.

[0033] The surface activity attenuation section is located at the front of the treatment zone. Within this section, alternating hydrophilic and hydrophobic regions are arranged along the flow direction of the second liquid stream. These regions can be formed by creating hydrophilic coatings, hydrophobic coatings, microstructured surfaces, or surface-modified layers on the inner wall of the microfluidic channel. After the second liquid stream enters the surface activity attenuation section, its liquid front briefly pauses at the boundary between the hydrophilic and hydrophobic regions before continuing forward under the impetus of the subsequent liquid stream, thus forming a liquid front pinning and re-release process. Through this process, the enrichment and spreading state of the tested dyeing and finishing auxiliary agent at the flow front in the second liquid stream can be altered, weakening the influence of the tested dyeing and finishing auxiliary agent on the wetting behavior in the detection zone, thereby reducing the interference of the tested dyeing and finishing auxiliary agent on the subsequent wetting response.

[0034] The reactivity attenuation section is located downstream of the surface activity attenuation section, and consumable reactive groups are immobilized within it. These consumable reactive groups can be implanted on the inner wall of the channel, a filling carrier, or a porous support within the reactivity attenuation section through grafting, embedding, adsorption, or gel fixation. When the second liquid stream, after passing through the surface activity attenuation section, enters the reactivity attenuation section, the dyeing and finishing auxiliary agent being tested comes into contact with the consumable reactive groups. These groups can react, complex, or adsorb with the auxiliary agent, thereby reducing its ability to participate in the reaction process in the detection zone. When the reactivity-attenuated second liquid stream enters the detection zone, its reaction response is weaker than that of the untreated first liquid stream, thus forming a second detection response that can be used for comparison.

[0035] An isolation liquid section is provided between the surface activity attenuation section and the reactivity attenuation section. This isolation liquid section can be formed from a blank extract, buffer solution, or carrier liquid that is compatible with the second liquid stream and does not contain the analyte dyeing and finishing auxiliary agent. After the second liquid stream passes through the surface activity attenuation section, the isolation liquid section separates the liquid front portion of the second liquid stream from the subsequent liquid, ensuring that the liquid front portion enters the reactivity attenuation section first, followed by the subsequent liquid. Through the separating effect of the isolation liquid section, the mixing between the enriched components at the liquid front and the subsequent liquid is reduced, allowing the reactivity attenuation section to exert a relatively stable attenuation effect on different flow segments and improving the repeatability of the second detection response.

[0036] The release liquid is introduced into the treatment zone in a reverse pulsed manner. The flow direction of the release liquid is opposite to that of the second liquid flow entering the treatment zone. During each pulse, the release liquid flows through the auxiliary agent response-weakening material, causing the test dyeing and finishing auxiliary agent adsorbed, bound, or trapped by the auxiliary agent response-weakening material to detach from the treatment zone. The flow rate of adjacent pulses increases according to a preset gradient; the preceding pulse releases test dyeing and finishing auxiliary agents with lower binding strength, and the following pulse releases test dyeing and finishing auxiliary agents with higher binding strength. The test dyeing and finishing auxiliary agents released from different pulses sequentially enter the detection zone and come into contact with the sensing interface within different time windows, thus forming a distinguishable third detection response. By identifying the third detection response within different time windows, information on the binding difference between the test dyeing and finishing auxiliary agent and the auxiliary agent response-weakening material can be obtained, improving the confirmatory power of the test results for the test dyeing and finishing auxiliary agent.

[0037] The processing zone contains at least two auxiliary response attenuation regions, each containing an auxiliary response attenuation material. These regions exhibit different binding strengths to the tested dyeing and finishing auxiliaries. The attenuation materials used in these regions can have different pore sizes, surface functional groups, charge properties, or hydrophilic / hydrophobic properties. When the second liquid flows through the processing zone, the tested dyeing and finishing auxiliaries undergo varying degrees of adsorption, binding, or retention within these attenuation regions. As the release liquid flows in the reverse direction through the attenuation regions, it first releases the tested dyeing and finishing auxiliaries with lower binding strength to the attenuation material, followed by those with higher binding strength, ensuring that the tested auxiliaries enter the detection zone in the order corresponding to their binding strength. Upon contact with the sensing interface, the tested dyeing and finishing auxiliaries in the detection zone generate a third detection response, thus providing auxiliary information for the identification and quantitative determination of the tested dyeing and finishing auxiliaries.

[0038] A holding solution is introduced between two consecutive pulses of the release solution. The holding solution can be a buffer solution, blank extract, or inert carrier solution that is compatible with both the release solution and the sample solution and does not contain the analyte. The holding solution forms a continuous flow path between the treatment and detection zones, maintaining the continuity of the flow path and reducing mixing of released components between adjacent pulses. The analyte released in the previous pulse enters the detection zone first under the influence of the holding solution, generating a third detection response. After the third detection response corresponding to the previous pulse is formed, a subsequent pulse releases an analyte with a higher binding strength, allowing the subsequently released analyte to enter the detection zone and generate a new third detection response. The separation of releases from adjacent pulses by the holding solution improves the temporal resolution of the third detection response and the readability of the results.

[0039] Example 1:

[0040] This embodiment provides a method for detecting trace amounts of dyeing and finishing auxiliaries in textiles based on a microfluidic intelligent sensor. This method is used to detect trace amounts of residual dyeing and finishing auxiliaries on the surface of textiles produced by a certain unit. During detection, the sampling end of the sensor is attached to the test area of ​​the textile, forming a closed sampling area between the sealed part of the sensor sampling end and the textile. An extraction solution is added to the closed sampling area, allowing the extract to contact and dissolve the dyeing and finishing auxiliaries on the surface of the textile. The sample solution containing the dyeing and finishing auxiliaries is then recovered through a return channel.

[0041] The extract can be an aqueous extract containing a buffer component, and the dyeing and finishing auxiliary agent to be tested can be a residual surfactant after textile dyeing and finishing. After the sample solution enters the microfluidic chip, it is divided into a first liquid flow and a second liquid flow through the flow channel within the chip. The first liquid flow enters the detection area directly without undergoing response attenuation treatment, and forms a first detection response by contacting the sensing interface in the detection area. The second liquid flow first enters the treatment area containing auxiliary agent response attenuation material, and then enters the detection area to contact the same sensing interface to form a second detection response.

[0042] See Figure 2 The closed sampling area is located before the sample inlet of the microfluidic chip and is used to explain the source of the sample liquid formed after the surface additives of the textile to be tested are extracted; the diversion channel is located inside the chip and divides the sample liquid into three sequential fluids: the first liquid flow, the liquid-carrying separation section, and the second liquid flow. Figure 2 The first liquid flow directly enters the same detection zone, and the second liquid flow enters the same detection zone after passing through the surface activity weakening section, the isolation liquid section, and the reactivity weakening section. The liquid-carrying separation section is used to create push and isolation between the first liquid flow and the second liquid flow, thereby enabling the un-weakened response and the weakened response to be compared on the same sensing interface.

[0043] The first and second liquid streams are detected in the same detection zone. To prevent mixing of the two streams upon entering the detection zone, a carrier liquid is introduced between the first and second streams, allowing them to enter the detection zone sequentially. The carrier liquid can be a blank extract without the analyte dyeing and finishing auxiliary agent. It is used to isolate the first and second streams and to push any residual sample liquid in the detection zone, ensuring that both the first and second detection responses are formed at the same sensing interface. This reduces the impact of differences in preparation and sensitivity between different sensing interfaces on the detection results.

[0044] The treatment zone is sequentially configured with a surface activity attenuation section and a reactivity attenuation section along the flow direction of the second liquid stream. The surface activity attenuation section contains alternating hydrophilic and hydrophobic regions, which can be formed through surface modification of the channel's inner wall. After the second liquid stream enters the surface activity attenuation section, its liquid front briefly pauses at the boundary between the hydrophilic and hydrophobic regions, and continues to advance under the impetus of subsequent liquid streams. This forms a liquid front pinning and re-release process, thereby altering the enrichment and spreading state of the tested dyeing and finishing auxiliary agent at the liquid front and reducing its impact on the subsequent wetting response.

[0045] The reactivity attenuation section is located downstream of the surface activity attenuation section, and it contains immobilized consumable reactive groups. When the second liquid stream, after passing through the surface activity attenuation section, enters the reactivity attenuation section, the dyeing and finishing auxiliary to be tested comes into contact with the consumable reactive groups. These groups react, complex, or adsorb the auxiliary, reducing its ability to participate in the reaction process in the detection zone. Consequently, the second detection response generated after the second liquid stream enters the detection zone is weaker than the first detection response.

[0046] An isolation liquid section is placed between the surface activity attenuation section and the reactivity attenuation section. This isolation liquid section can be formed from a carrier liquid compatible with the sample solution and free of the dyeing and finishing auxiliaries to be tested. After the second liquid flow passes through the surface activity attenuation section, the isolation liquid section separates the liquid leading edge of the second liquid flow from the subsequent liquid, allowing the liquid leading edge to enter the reactivity attenuation section first, followed by the subsequent liquid. This separation reduces the mixing between the enriched components at the liquid leading edge and the subsequent liquid, enabling the reactivity attenuation section to exert a relatively stable attenuation effect on different flow segments and improving the repeatability of the second detection response.

[0047] In this embodiment, the first and second detection responses can be represented by current responses. To evaluate the degree of response attenuation after the second liquid flow passes through the treatment zone, the response attenuation rate is used for calculation, and its formula is as follows:

[0048]

[0049] Where A represents the response attenuation rate of the second liquid flow relative to the first liquid flow after passing through the treatment zone, in percentage (%). This represents the first detection response formed by the first liquid flow in the detection zone, expressed in μA. This represents the second detection response formed in the same detection zone after the second liquid flow passes through the surface activity attenuation section and the reactivity attenuation section, expressed in μA. The derivation of this calculation formula is based on the following approach: firstly, using... This represents the reduction in response caused by the adjuvant response attenuation treatment, and then this reduction in response is compared with the first detection response without attenuation treatment. By comparing the two flows, the relative attenuation of the second flow relative to the first flow can be obtained.

[0050] The first detection response obtained after the first liquid flow enters the detection zone during a single detection process. The second detection response was obtained after the second liquid flow passed through the processing zone and entered the same detection zone at a current of 0.86 μA. The value is 0.49 μA. Substituting the above data into the formula for calculating the response decay rate, we get:

[0051]

[0052] See Figure 3 The first fluid flow window, the liquid-carrying isolation window, and the second fluid flow window are arranged sequentially according to the time sequence of their entry into the detection zone. The curve reflects the change in current response at the same sensing interface when different fluids enter. A higher response peak appears in the first fluid flow window, corresponding to... The response was 0.86 μA; within the liquid-carrying isolation window, the response decreased and approached the background level, reflecting the liquid's pushing and isolation of the previous flow residue; within the second flow window, the response increased again but the peak value decreased, corresponding to... The response time is 0.49 μA. This timing response indicates that the second flow, after being weakened by the processing zone, can still be detected by the same sensing interface, but its response amplitude is significantly lower than that of the first flow.

[0053] The above calculation results show that the detection response of the dyeing and finishing auxiliary agent in the second liquid stream is significantly attenuated compared to the first liquid stream after passing through the surface activity attenuation section and the reactivity attenuation section. This indicates that the treatment zone can effectively reduce the contribution of the dyeing and finishing auxiliary agent to the response in the detection zone. Since the first and second detection responses are formed at the same sensing interface, this response attenuation rate can well reflect the treatment effect of the auxiliary agent response attenuation material on the dyeing and finishing auxiliary agent.

[0054] To further determine the residual amount of the dyeing and finishing auxiliaries in the tested textiles, a conversion formula was used to calculate the residual amount based on the pre-established relationship between the response decay rate and the residual amount using standard samples. The formula is as follows:

[0055]

[0056] Where M represents the residual amount of the dyeing and finishing auxiliary to be tested in the textile being tested, in mg / kg; A represents the response decay rate; p represents the conversion factor obtained from the pre-calibration of the standard sample; and q represents the correction term corresponding to the blank substrate or system background. The derivation of this formula is based on the fact that, within the set detection range, the response decay rate and the residual amount of the dyeing and finishing auxiliary to be tested have an approximately linear relationship. Therefore, after obtaining the conversion factor p and the correction term q through standard sample calibration, the residual amount of the dyeing and finishing auxiliary to be tested can be calculated from the response decay rate.

[0057] In this embodiment, p was pre-calibrated to be 1.18 mg / kg and q to be 2.6 mg / kg. Substituting the response decay rate A of 43.0 into the conversion formula for the detection result, we obtain:

[0058]

[0059] See Figure 4 The standard sample calibration line represents the linear relationship between the response decay rate and the residual amount. The value range of Example 1 corresponds to a detection interval with a response decay rate of approximately 43.0%. The conversion point of the test sample is determined by the vertical dashed line and the horizontal dotted line. The vertical dashed line corresponds to a response decay rate A of 43.0%, and the horizontal dotted line corresponds to a residual amount M of 53.34 mg / kg. This figure can intuitively illustrate that after the response decay rate of the sample is converted according to the calibration relationship, the residual amount of the dyeing and finishing auxiliary agent to be tested on the surface of the textile can be obtained.

[0060] Therefore, the residual amount of the dyeing and finishing auxiliary agent on the surface of the textile to be tested was determined to be 53.34 mg / kg. The above data is only used to illustrate the conversion process between the detection response and the detection result in this embodiment, and does not constitute a limitation on the detection object, detection range, or protection scope.

[0061] In this embodiment, the sample solution is divided into a first liquid stream and a second liquid stream. The first liquid stream provides a detection response without attenuation treatment, while the second liquid stream, after passing through a surface activity attenuation section, a barrier liquid section, and a reactive activity attenuation section, provides a detection response after attenuation treatment. The two streams form a comparable response difference at the same sensing interface in the same detection area. This method can reduce the impact of differences between different sensing interfaces, sample solution background, and textile substrate interference on the detection results, and improve the accuracy of judging the difference between the first and second detection responses.

[0062] Example 2:

[0063] This embodiment provides a method for trace detection of dyeing and finishing auxiliaries in textiles based on a microfluidic smart sensor, used to confirm the detection of residual dyeing and finishing auxiliaries on the surface of a textile product provided by a certain unit. During detection, the sampling end of the sensor is attached to the test area of ​​the textile product, forming a closed sampling area between the sensor sampling end and the textile product. An extraction solution is added to the closed sampling area, allowing the extraction solution to contact the dyeing and finishing auxiliaries on the surface of the textile product and form a sample solution. Subsequently, the sample solution is recovered and introduced into the microfluidic chip.

[0064] In this embodiment, the sample solution is divided into a first liquid flow and a second liquid flow through a diversion channel within the microfluidic chip. The first liquid flow directly enters the detection zone and contacts the sensing interface to obtain a first detection response. The second liquid flow first enters the processing zone equipped with an auxiliary agent response attenuating material, and then enters the detection zone to contact the sensing interface to obtain a second detection response. The auxiliary agent response attenuating material is used to adsorb, bind, or retain the dyeing and finishing auxiliary agent to be tested in the second liquid flow, so that the detection response of the second liquid flow entering the detection zone is reduced relative to that of the first liquid flow.

[0065] See Figure 5 The closed sampling area transfers the dyeing and finishing auxiliaries on the surface of the textile to be tested into the sample solution. After entering the microfluidic chip, the sample solution forms a first liquid flow and a second liquid flow through the diversion channel. The first liquid flow directly enters the detection area to form the first detection response, and the second liquid flow sequentially passes through the low binding strength weakening area, the medium binding strength weakening area, and the high binding strength weakening area before entering the detection area to form the second detection response. A reverse communication path is formed between the release liquid inlet and the treatment area. Pulses I, II, and III act sequentially along the reverse path on the weakening areas of different binding strengths, and the holding liquid is used to maintain the continuity and separation of the liquid segments between adjacent release pulses.

[0066] At least two auxiliary response attenuation zones are set up within the treatment zone. Each auxiliary response attenuation zone contains auxiliary response attenuation materials, and the binding strength of the dyeing and finishing auxiliary to be tested varies in different auxiliary response attenuation zones. When the second liquid stream passes through the treatment zone, the dyeing and finishing auxiliary to be tested undergoes different degrees of adsorption, binding, or retention in different auxiliary response attenuation zones according to the interaction strength between it and the different auxiliary response attenuation materials.

[0067] After obtaining the second detection response, a release liquid is introduced into the treatment zone in the reverse direction. The flow direction of the release liquid is opposite to that of the second liquid flow entering the treatment zone, causing the test dyeing and finishing auxiliary agent that was adsorbed, bound, or trapped by the auxiliary agent response-weakening material to be released from the treatment zone and enter the detection zone with the release liquid. The released test dyeing and finishing auxiliary agent forms a third detection response after contacting the sensing interface, which is used to further confirm the test dyeing and finishing auxiliary agent that was weakened or trapped in the second liquid flow by the treatment zone.

[0068] The release solution is introduced into the treatment zone in a reverse pulse pattern, with the flow rate of adjacent pulses increasing according to a preset gradient. The preceding pulse with a smaller flow rate preferentially releases the dyeing and finishing auxiliaries to be tested, which have lower binding strength to the material and weaken the response of the auxiliary agent. The subsequent pulse with a larger flow rate further releases the dyeing and finishing auxiliaries to be tested, which have higher binding strength. The dyeing and finishing auxiliaries to be tested released by different pulses enter the detection zone sequentially and form a distinguishable third detection response within different time windows.

[0069] A holding solution is introduced between two consecutive pulses of the release solution. The holding solution can be a buffer solution or a blank extraction solution that is compatible with the sample solution and the release solution and does not contain the analyte dyeing and finishing auxiliary. The holding solution forms a continuous liquid segment between the processing zone and the detection zone, which is used to maintain the continuity of the flow path and reduce the mixing between the components released by adjacent pulses. This allows the analyte dyeing and finishing auxiliary released in the previous pulse to enter the detection zone first and form the third detection response, and then the analyte dyeing and finishing auxiliary with a higher binding strength is released in the subsequent pulse to enter the detection zone and form a new third detection response.

[0070] See Figure 6 The third detection response forms three peak-shaped windows according to the timing of the reverse release into the detection zone. The first release window corresponds to low-binding release, and the integral value of the third detection response... The value is 18.6; the second release window corresponds to the combined release, and the third detection response integral value. The value is 27.4; the third release window corresponds to high-binding release, and the integral value of the third detection response is... The value is 34.0. A holding liquid interval is set between adjacent release windows so that after the component released by the previous pulse enters the detection zone and forms a response, the component released by the next pulse enters the detection zone, thereby distinguishing components with different binding strengths from each other on the time axis.

[0071] To illustrate the release contribution corresponding to different release pulses, this embodiment uses the step-release ratio for calculation, and the calculation formula is as follows:

[0072]

[0073] in, This represents the percentage of the dyeing and finishing auxiliary agent released corresponding to the i-th release pulse, expressed in % (%). This represents the area of ​​the third detection response peak or the integral value of the third detection response formed within the corresponding time window by the i-th release pulse. This represents the sum of the peak areas of the third detection response corresponding to all release pulses. The derivation of this formula is based on the idea that each release pulse corresponds to a portion of the dyeing and finishing auxiliary agent being adsorbed, bound, or retained by the material weakened by the auxiliary agent's response. This portion of the auxiliary agent enters the detection zone and forms a corresponding third detection response. The single response amount... With total response By comparison, the proportion of the released product in this pulse can be obtained in the total released products.

[0074] During a single detection process, the integral value of the third detection response corresponding to the first release pulse. The integral value of the third detection response corresponding to the second release pulse is 18.6. The integral value of the third detection response corresponding to the third release pulse is 27.4. The integral value of the third detection response corresponding to all released pulses is 34.0. The value is 80.0. Substituting the above data into the formula for calculating the proportion of tiered release, we get:

[0075]

[0076]

[0077]

[0078] The above results indicate that as the release pulse flow rate gradient increases, the release ratio corresponding to subsequent pulses increases, indicating that there is a component of the dyeing and finishing auxiliary agent to be tested in the treatment area that has a high binding strength with the auxiliary agent response weakening material, and that this component needs to be released into the detection area under the action of a higher flow rate pulse.

[0079] To further confirm the effectiveness of the third detection response, this embodiment uses a pulse release confirmation value for calculation, the formula of which is:

[0080]

[0081] Where T represents the overall confirmation value of the third detection response; , and These represent the area or integral value of the third detection response peak obtained within different time windows for the three release pulses; , and These represent the weighting coefficients for different release pulses. The weighting coefficients are used to reflect the differences in the contribution of released components with different binding strengths to the detection confirmation. Components released later in the sequence usually correspond to stronger binding or retention effects, so subsequent release windows can be given higher weights to enhance the ability of the third detection response to confirm the presence of the analyte dyeing and finishing auxiliary.

[0082] In this embodiment, It is 0.25. It is 0.35. It is 0.40. It is 18.6. It is 27.4. The value is 34.0. Substituting the above data into the formula for calculating the pulse release confirmation value, we get:

[0083]

[0084] When the preset confirmation threshold is 20.00, T is 27.84, which is higher than the preset confirmation threshold, indicating that the third detection response formed by the reverse release liquid pulse elution has a valid confirmation signal. The above data is used to illustrate the graded release and confirmation calculation process in this embodiment and does not constitute a limitation on the detection object, the number of release pulses, the release flow gradient, or the protection range.

[0085] See Figure 7 The release percentages corresponding to the first, second, and third pulses were 23.25%, 34.25%, and 42.50%, respectively. The column height increased with the increase of the release pulse sequence, indicating that the proportion of the retained component with higher binding strength was relatively large. Figure 7 The confirmation judgment area on the right shows both the preset confirmation threshold of 20.00 and the comprehensive confirmation value of 27.84. The comprehensive confirmation value is above the confirmation threshold, indicating that the third detection response can effectively confirm the presence of the dyeing and finishing auxiliary to be tested.

[0086] In this way, the second liquid flow is first adsorbed, bound, or trapped by the auxiliary material in the treatment zone, and then released in the reverse direction by the release liquid according to the pulse gradient. The components released by adjacent pulses are separated by the holding liquid, so that the dyeing and finishing auxiliaries to be tested with different binding strengths form a distinguishable third detection response in different time windows, thereby improving the confirmation ability, time resolution and readability of the detection results of the dyeing and finishing auxiliaries to be tested.

Claims

1. A method for detecting trace amounts of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors, characterized in that, The sensor sampling end is attached to the textile to be tested to form a closed sampling area. An extraction solution is added to the closed sampling area to recover the sample solution containing the dyeing and finishing auxiliary agent to be tested. The sample solution is introduced into the microfluidic chip and divided into a first liquid flow and a second liquid flow. The first liquid flow directly enters the detection area and obtains a first detection response in the detection area. The second liquid flow first passes through a treatment area equipped with an auxiliary agent response weakening material and then enters the detection area to obtain a second detection response. The auxiliary agent response weakening material is used to adsorb, bind, consume or shield the dyeing and finishing auxiliary to be tested, so as to reduce the electrochemical response, impedance response, optical response, wetting response or reaction response of the dyeing and finishing auxiliary to be tested in subsequent detection. The detection results of the dyeing and finishing auxiliary agent in the textile to be tested are obtained based on the response difference, response ratio, or response decay rate between the first detection response and the second detection response.

2. The method for trace detection of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 1, characterized in that, The first liquid flow and the second liquid flow are separated by a carrier liquid and then enter the same detection area in sequence, so that the first detection response and the second detection response are formed at the same sensing interface.

3. The method for trace detection of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 1, characterized in that, The treatment zone is provided with a surface activity weakening section and a reactivity weakening section along the second liquid flow direction, so that the surface activity and the ability of the dyeing and finishing auxiliary agent to be tested in the second liquid flow are reduced sequentially.

4. The method for detecting trace amounts of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 1, characterized in that, A release liquid is reverse-flowed into the treatment zone, allowing the dyeing and finishing auxiliary agent to be tested, which has been adsorbed, bound, or retained by the auxiliary agent response-weakening material, to enter the detection zone and generate a third detection response.

5. The method for trace detection of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 3, characterized in that, The surface activity weakening section is provided with alternating hydrophilic and hydrophobic regions, so that the second liquid flow will be pinned and re-released when passing through the surface activity weakening section, thereby reducing the influence of the dyeing and finishing auxiliary to be tested on the subsequent wetting response.

6. The method for trace detection of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 3, characterized in that, The reactive activity attenuation section contains consumable reactive groups, which bring the second liquid stream after passing through the reactive activity attenuation section into contact with the consumable reactive groups, thereby reducing the reaction response of the dyeing and finishing auxiliary to be tested in the detection area.

7. The method for trace detection of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 3, characterized in that, An isolation liquid section is provided between the surface activity weakening section and the reactivity weakening section, so that the liquid leading edge of the second liquid after passing through the surface activity weakening section is separated from the subsequent liquid before entering the reactivity weakening section.

8. The method for trace detection of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 4, characterized in that, The release liquid is introduced into the treatment zone in a reverse pulse manner. The flow rate of adjacent pulses increases according to a preset gradient, causing the dyeing and finishing auxiliaries to be tested, which have different binding strengths with the auxiliary response weakening material, to detach sequentially and form the distinguishable third detection response within different time windows.

9. The method for trace detection of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 4, characterized in that, The processing area is provided with at least two auxiliary response weakening regions containing the auxiliary response weakening material and having different binding strengths. When the release liquid flows in reverse through each auxiliary response weakening region, the dyeing and finishing auxiliary to be tested enters the detection area in the release order corresponding to the binding strength and generates the third detection response.

10. The method for trace detection of textile dyeing and finishing auxiliaries based on microfluidic intelligent sensors according to claim 8, characterized in that, Between two adjacent pulses of the release liquid, a holding liquid is introduced to maintain the continuity of the flow path from the treatment zone to the detection zone, and to allow the dyeing and finishing auxiliary to be tested released in the previous pulse to first enter the detection zone to generate the third detection response, and then the dyeing and finishing auxiliary to be tested with a higher binding strength is released in the next pulse.

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