50 results about "Spr biosensor" patented technology

The invention provides a chip for an SPR bioreactor in the field of optical sensors as well as a preparation method and application of the chip. The chip is composed of a glass substrate, a graphene or graphene oxide / polymer compound film and a gold film generated in an evaporation manner in order from bottom to top, wherein the polymer compound is polyacrylic acid or a polyacrylate. According to the preparation method, a layer of graphene / polymer compound film material is added between the glass substrate and the gold film, and the detection sensitivity of the SPR sensor is enhanced by virtue of the surface plasma resonance effect, which is better than that of the gold film, of the graphene; the SPR sensor manufactured by use of the method is high in sensitivity, simple and convenient in preparation method, and widely applicable to the fields such as biology, medicine, chemistry and environments.

A surface plasmon resonance biosensor device and system are provided. The simplicity of SPR biosensor design allows easy integration with both QCM and electrochemistry techniques, not found in current SPR biosensor devices. In some embodiments, the surface plasmon resonance biosensor device has a dual SPR / QCM sample holder which allows simultaneous detection by both surface plasmon resonance and also quartz crystal microbalance (QCM) techniques. In additional embodiments, the surface plasmon resonance biosensor device and / or the dual SPR / QCM technique can be integrated with electrochemistry techniques by incorporate reference and counter electrodes in the SPR or SPR / QCM sample holder. Methods of using the device and system to determine whether an analyte of interest is present in a sample are also provided.

The present invention relates to a surface plasmon resonance (SPR) biosensor, especially to a micro prism array SPR biosensor module. The objective of the present invention is to resolve problems in the technology in existence, such as that the operation course to build up a SPR biosensor is two complicated and tedious, and the technological request is too high. Said micro prism array SPR biosensor module comprises a SPR biosensor and prisms which is a micro prism array comprising at least one line prisms, wherein said micro prism array contains a base level which tother side is plated with gold film, silver film and chromium film at positions corresponding to places where the prisms locate. Said micro prism array SPR biosensor module radically simplifies the operation course to build up a SPR sensor; and improves the quality of detection signals at the same time, and is capable of performing a plurality of detections at one time. The sensor module has a low manufacturing cost, and then it is favourable to promote the application of said sensor module in clinical tests.

The invention discloses a multi-channel surface plasma wave sensing-monitoring system, which comprises a SPR biological sensing-monitoring device, an incident light channel, an exit light channel and an intelligent analysis processing platform, wherein the SPR biological sensing-monitoring device comprises a SPR biological sensor and an adjustable detecting light source, the incident light channel comprises a cruising adjustable polarized light source which comprises a polarized light source and a control system, and the exit light channel comprises a convergent lens and a photodetector. The multi-channel surface plasma wave sensing-monitoring system can accurately analyze the interaction (the function of multiple factors) of various matters in specimens, avoids system deviation which is brought by single measurement, greatly reduces monitoring time, and improves monitoring efficiency. The invention has the advantages of compact structure, convenient carrying, convenient employment and high sensitiveness, which can be applied in a plurality of fields and various environments, and has wide application prospect.

The invention relates to a prism-coupled SPR biosensor, which comprises an optical plastic prism, an inner metal film layer, an outer metal film layer and a biological component layer; The outer metal film layer is deposited on the film layer, the inner metal film layer and the outer metal film layer can be two kinds of the same or different metal film layers, and the sum of the thickness of the inner metal film layer and the outer metal film layer is between 20-80nm The space meets the optical requirements for exciting surface plasmon resonance, and a biological component layer is fixed on the surface of the outer metal film layer. The present invention also relates to the use of the prism-coupled SPR biosensor in preparing biochips and its use in detecting interactions between biological samples.

The invention discloses a method for detecting an object to be detected by using an SPR biosensor. The method uses a biotin-streptavidin-magnetic particle as a signal reporting molecule which can amplify a signal of a hybridization result; therefore, the problem that marking of a probe or an object to be detected before hybridization influences natural binding of biological molecules is avoided, the requirement of improving detection sensitivity of the SPR biosensor is realized, and generated signals are stable and are easy to detect, which enables result detection and analysis to be substantially simplified. According to the invention, amplification of a detection signal is realized after hybridization, so variation and variation quantity of SPR signals before and after the detection signal is amplified can be more visually and clearly observed; meanwhile, the biotin-streptavidin-magnetic particle technology is used in the invention, and no expensive detector is needed, thereby reducing technical cost and economic cost needed for enhancing sensitivity of the biosensor.

The invention provides a tilted fiber Bragg grating (TFBG)-based surface plasmon resonance (SPR) biosensor which is characterized by comprising a broadband light source (1), a polarizing beam splitter prism (2), an optical isolator (3), a TFBG (4) coated with gold / biological adsorption layer, a reaction tank (5) and a spectrum analyzer (6), wherein the broadband light source (1) and the polarizing beam splitter prism (2) are connected with each other by virtue of an optical fiber and then are connected with the optical isolator (3); and the TFBG (4) coated with the gold / biological adsorption layer is arranged in the reaction tank (5) and is connected with the optical isolator (3) and the spectrum analyzer (6). The TFBG serves as a sensing part, and compared with a common optical fiber SPR sensor, the SPR biosensor disclosed by the invention has the advantages that the wavelength of the light source is simply changed, any mode of emitting light to a fiber core-cladding layer at different angles can be almost generated, resonance is easily realized, the resonance strength is greatly improved, and the information detection capacity is greatly enhanced; the sensitivity of the detector is greatly improved, and the detector can be used for detecting change of concentration of a solution with small biological molecules; and moreover, bovine serum albumin is adopted by the biological adsorption layer, and thus the interaction process between protein-protein and antibody-receptor biological proteins can be efficiently and accurately monitored.

The invention relates to a multiple-DOF (degree of freedom) adjusting mechanism of an optical SPR (surface plasma resonance) biosensor. The mechanism comprises a laser regulating unit, a biochip component, a CCD (charge coupled device) regulating unit, a support plate and a base used for mounting the support plate, wherein the laser regulating unit and the CCD regulating unit are symmetrically arranged at the two sides of the prism bracket, and certain light paths can be formed among a laser, the biochip component and a CCD by adjusting the relative position of the laser regulating unit and the CCD regulating unit. The mechanism provided by the invention has the advantages that the structural design is delicate, and the location is accurate, thus the consistency of the light paths among the laser, the biochip component and the CCD can be conveniently adjusted; the pressure between a flow cell and the biochip component can be conveniently adjusted; the flow cell can maintain to be circulated after being lifted and reset and the accurate location of the biochip component can be guaranteed; the problems that debugging is difficult and the refractive index is difficult to match as the biochip provided with a glass substrate is replaced only are solved, the analysis accuracy of the biosensor is improved, and the use cost and the maintenance cost of the optical SPR sensor are greatly reduced.

The present invention makes non-grating surface plasmon resonance (SPR) optical coupler with plastic to replace optical glass, and belongs to the field of waveguide optics and biological sensing technology. The disposable low cost optical coupler made with low refractive index plastic has low cost, less noise, raised SPR biosensor S / N ratio, convenient instrument operation, and convenient integration with other parts. The SPR biosensor of the present invention may be used in clinical detection, sanitary environment monitoring, industrial production and basic life science research relative to mutual action of macro biomolecules.

The invention provides a method for detecting viruses through a surface plasma resonance technology (SPR), which comprises the steps as follows: a sample to be detected is mixed with a buffer solution including an SSPE solution and a dextran sulfate solution, and the formed mixture contains a solution of 1-10 multiplied by SSPE and 0.5 to 10 percent of the dextran sulfate solution; the mixture isled to flow through an SPR biosensor chip; a probe special to the viruses is connected with the chip; the signal difference of corresponding flowing pools before and after the mixture flows through the chip is measured through the SPR; and the signal difference and the signal difference of a comparison flowing pool are compared so as to determine whether the viruses exist. The method is especially suitable for detecting human papillomavirus (HPV). In addition, the invention further provides the SPR biosensor chip used in the method.

In order to solve the problem of low sensitivity of existing fiber optic SPR biosensors, the invention provides a sensitized fiber optic SPR sensor based on graphene oxide and gold nanorods. Accordingto the sensitized fiber optic SPR sensor based on the graphene oxide and the gold nanorods, the plasmon coupling effect between a plasma wave on the surface of a gold film and a local surface plasmawave on the surface of the gold nanorods is utilized to enhance the electric field strength. At the same time, the charge transfer between the gold film and the gold nanorods can be promoted by the graphene oxide, so that interactions between a surface plasma wave and a substance to be detected is enhanced, and the detection sensitivity is improved. In addition, the graphene oxide has excellent bio-sensing characteristics, biocompatibility, and a large specific surface area, can better measure biomass and chemical quantities. Compared to an ordinary fiber optic SPR sensor, the sensitized fiberoptic SPR sensor based on the graphene oxide and the gold nanorods has higher sensing sensitivity and chemical stability, real-time monitoring can be performed, the structure of the sensor is compact, thereby being able to widely applied in the fields of physics, chemistry, biology, medical care, food safety and the like.

The invention relates to a dual-channel MDOF (multidegree of freedom) adjustment mechanism of an optical surface plasma resonance biosensor. The mechanism comprises a biochip assembly regulating unit, an optical path regulating unit, an angle regulating unit and a supporting and guiding unit, wherein the optical path regulating unit comprises a laser swing frame and a charge coupled device (CCD) swing frame; the angle regulating unit comprises an elevating assembly, a rotating support arm, a transmission shaft and a driving device; driven by the driving device, the transmission shaft drives the elevating assembly to complete the elevating travel, and at the same time, drives the laser swing frame and the CCD swing frame to form an included angle within a certain range via the corresponding rotating support arm, and form two corresponding optical path detection passages among laser, a CCD image sensor and the biochip assembly. The dual-channel MDOF adjustment mechanism provided by the invention is convenient for operation and accurate in positioning and has high testing precision, and solves the problems, such as debugging difficulty and hard refractivity matching caused when only the biochip with a glass substrate is replaced, thereby increasing the analytic precision of the biosensor and also substantially reducing the using and maintaining cost of the optical surface plasma resonance (SPR) sensor.

The invention discloses a preparation method of surface plasma resonance chips. The preparation method is characterized in that a disulfide bond reducing agent is adopted to modify biological protein molecules containing hydrosulfide group and / or disulfide bond; then, protein substrate is established on the surface of a chip by means of metal surface molecule self-assembly technology; and further modification is carried out to realize the preparation of a novel sensing chip used in SPR biosensor. The preparation method has the advantages of low preparation cost, simple operation, less time consumption and safety and harmlessness; moreover, the prepared chip has the functions of commercialized CM5 chips, thereby providing new possibilities for solving the prior problems of fewer types of surface plasma resonance chips and high cost.

The invention relates to a dual-channel optical fiber SPR sensor. The dual-channel SPR sensor comprises a reference channel and a sensing channel; the reference channel serves as a blank control reference channel and detects a wavelength shift quantity caused by non-specific adsorption; and the sensing channel improves the detection sensitivity of the sensor by enhancing the intensity of a local electric field through utilizing a coupling effect between a gold film and gold nanoparticles, and improves the immobilization efficiency of an antibody by utilizing a graphene oxide thin film. The twochannels in the dual-channel optical fiber SPR sensor use different metal films respectively, so that two resonance valleys are generated, double-channel sensing is realized, and the unique advantages of eliminating a measuring error caused by the non-specific adsorption and being insensitive to the temperature are achieved; and the two SPR resonance valleys of the two channels are separated fromeach other, so that the SPR resonance valleys are prevented from generating the adverse effects mutually in the detection process, and biological sensing is better facilitated. According to the sensor, the problems that the sensor is low in sensitivity and easy to influence by liquid refractive index change and temperature fluctuation in the prior art are effectively solved.

The invention discloses a biological chip for rapidly detecting pre-pregnant intrauterine toxoplasma gondii and cytomegalovirus infection. Compared with an antibody in traditional detection technique, an oligonucleotides adapter has the advantages that the binding force between the oligonucleotides adapter and target molecule is higher, stability is good, accuracy is high, repeatability is good, screening period is shorter, can be repeatedly used, can be stored for long time, can be precisely modified at sites, and the like; and by placing the obtained biological chip in a SPR (surface plasmon resonance) biosensor for detection, (1) the real-time detection is realized, (2) the sample does not need to be labeled, (3) the consumption of the sample is extremely low, (4) the detection processis convenient and efficient, and has high sensitivity, (5) the application range is very broad, (6) the flux is high, (7) in most cases, the sample does not need to be pretreated, and (8) the turbid or even nontransparent samples can be detected.

The invention discloses a composite enrichment medium for Escherichia coli, Salmonella and Listeria monocytogenes and a preparation method thereof. The composite enrichment medium for Escherichia coli, Salmonella and Listeria monocytogenes comprises 16.0-18.0 parts of tryptone, 2.0-4.0 parts of peptone, 5.0-7.0 parts of yeast extract, 10.0-20.0 parts of sodium chloride, 2.4-2.6 parts of dipotassium phosphate, 9.5-9.7 parts of disodium hydrogen phosphate, 1.34-1.36 parts of monopotassium phosphate, 0.005-0.020 part of acriflavine, 2.0-8.0 pars of magnesium chloride, 1.0-4.0 parts of glucose, 1.0-4.0 parts of sodium pyruvate and 1000 parts of distilled water, and has pH of 6.8-7.4. The composite enrichment medium herein allows three target pathogens to be enriched at a high, constant speed;after 16-24 hours of enrichment, quick detection of the three target pathogens can be implemented to provide a diagnostic report through high-flux detection devices, such as multiple PCR (polymerase chain reaction), multi-channel SPR (surface plasma resonance) biosensors, and multi-channel BLI (biolayer interferometry) biosensors.

The invention discloses a cytomegalovirus antibody aptamer specific to cytomegalovirus, and a biochip formed by the cytomegalovirus antibody aptamer simultaneously. Compared with the antibody in the traditional detection technique, the oligonucleotide aptamer disclosed by the invention has the advantages of stronger binding force with a target molecule, good stability, high accuracy, good repeatability, shorter screening period and the like, and can be repeatedly used, stored for a long term and used for accurate site modification. When put into an SPR (surface plasmon resonance) biosensor for detection, the obtained biochip can realize real-time detection, no need of marking samples, a very small required amount of samples, convenient, quick and highly-sensitive detection process, wide range of application, high flux, and detection of a turbid or even opaque sample under most conditions.

The invention discloses a method for detecting target genes in plants and a special surface plasmon resonance (SPR) biosensor thereof. The method comprises the following steps of: 1) extracting deoxyribonucleic acids (DNA) of genomes of biont to be detected as templates, and performing polymerase chain reaction (PCR) amplification by taking primer pairs in the following reagents as primers to obtain PCR products; 2) modifying the PCR products obtained in the step 1) into single-stranded DNA molecules; and 3) allowing solution of the obtained single-stranded DNA molecules to flow through the SPR biosensor, and if the detected response values (RU) are changed, determining that the plants to be detected contain the target genes, or if the RU values are not changed, determining that the plants to be detected do not contain the target genes. Experiments prove that the SPR biosensor enveloped with a probe is constructed and is used for detecting whether genetic cotton contains a CrylAc gene or not, so the SPR biosensor has the advantages of high sensitivity and flux and automation and is easy to operate.

The invention discloses a single mode fiber with a surface waveguide, an SPR biosensor and a preparation method thereof. The single mode fiber comprises: a fiber core and a cladding layer, which constitute a total reflection condition, wherein the cladding layer covers the fiber core, the cladding layer contains the surface waveguide therein, the surface waveguide is close to the surface of the cladding layer, the surface waveguide is written by the femtosecond laser direct writing waveguide technology, the surface waveguide is used to generate a strong evanescent field for exciting an SPR effect without destroying a physical structure of the optical fiber, so that the single mode fiber has relatively high mechanical strength, since the single mode fiber contains the surface waveguide, thelight wave energy in the fiber core can be guided to the surface of the fiber to generate the strong evanescent field, the fabrication is simple, the excitation efficiency is high, further, the SPR biosensor comprising the above single mode fiber also avoids the problems that the physical structure is destroyed and the mechanical strength is low, and the single mode fiber disclosed by the invention also has the advantages of high efficiency of exciting the SPR effect and simple preparation process.

A method of coating an SPR biosensor specific for an analyte to reduce protein fouling, the method has the steps of providing an SPR biosensor, providing a solution of 11-mercaptoundecanol; incubating the SPR biosensor in the 11-mercaptoundecanol solution to form a self-assembling monolayer (SAM); incubating the SPR with SAM in a solution of epichlorohydrin and diglyme; next incubating the SPR in ethanolamine; preparing a solution of EDCNHS and a biocompatible polymer; incubating the SPR from ethanolamine in the EDC / NHS / polymer solution; providing a ligand specific for the analyte in a solution; incubating the polymer-coated SPR in the ligand solution to permit the ligand to react with the polymer-coated SPR; washing the ligand-coated SPR to remove unreacted ligand, thereby providing an SPR capable of reacting with the analyte. Another method replaces the solution for the SAM layer with a solution of MHA or NHS-MHA with HT, and attaches the ligand to the resulting SAM layer.

The invention provides a preparation method of a D-type plastic optical fiber based on a graphene gold film and application of the preparation method in an SPR biosensor. The invention relates to thetechnical field of optical fiber sensors. The preparation method comprises the following steps: firstly coating a gold film with a copper foil / graphene material, enabling the gold film layer to be seamlessly attached to the graphene layer, and then etching the obtained copper foil / graphene / gold material with ferric chloride solution to remove the copper foil, so as to obtain a graphene / gold material; and attaching the gold film layer in the graphene / gold material to the cut surface of the D-type plastic optical fiber so as to obtain the D-type plastic optical fiber. The gold film layer and thegraphene layer in the D-type plastic optical fiber prepared by the preparation method disclosed by the invention are seamlessly bonded, so the interference of copper atoms is eliminated, and the detection sensitivity can reach 1,219.95 nm / RIU. Compared with the sensitivity of an optical fiber sensor obtained by sequentially attaching a gold film layer and a graphene layer to a D-type optical fiber in the prior art, the sensitivity of the optical fiber sensor is remarkably improved.

The invention provides an automatic high-flux SPR detector. The automatic high-flux SPR detector comprises a laser device, an SPR exciting light group, an SPR biosensor, a detection signal collector,a control and analysis unit, a flow pipeline, an automatic sampling device, an automatic cleaning device and an automatic waste collection device, wherein the laser device, the SPR exciting light group and the SPR biosensor are connected with the control and analysis unit through the detection signal collector, and the flow pipeline is connected with the SPR biosensor, the automatic sampling device and the automatic cleaning device. The device can detect a plurality of indexes of a plurality of samples simultaneously; biochips and sampling needles can be recycled, so that the cost is reduced;a reference channel is arranged, so that the influence of non-specific binding, sample composition, temperature and other factors on result analysis is reduced; cleaning, sampling and waste collectionare fully automatic; parts are convenient to replace, and the service life is long.

The present invention relates to a method of evaluation of molecular binding interactions at a sensing surface, and more particularly to a method for evaluation of screening data obtained from an interaction between an analyte in a fluid sample and a ligand immobilized on a sensor surface of a biosensor that is independent of interaction models. Preferably the biosensor is a SPR biosensor.The invention also relates to a biosensor system arranged to perform the method and a computer program arranged to control the operation of the biosensor system.

The invention discloses an SPR biosensing system for detecting a CTC. The SPR biosensing system includes an SPR biosensor, a cell membrane functionalized nanoparticle and a folate modified nanoparticle; the SPR biosensor includes an immunochip having a surface modified by a JUP antibody; the cell membrane functionalized nanoparticle contains a JUP protein and a folate receptor; the cell membrane functionalized nanoparticle is combined with the immunochip via an interaction of an antigen-antibody; and the folate modified nanoparticle is combined with the cell membrane functionalized nanoparticle via an interaction of a folate-folate receptor. According to the SPR biosensing system provided by the invention, the CTC is combined at dual selectivity by using the cell membrane functionalized nanoparticle and the folate modified nanoparticle, a false positive problem caused by single antigen-antibody specificity identification is improved, the detection cost is low, and the operation is convenient.

The invention relates to a Dectin-1 fusion protein expression vector and application thereof, and also relates to construction of the fusion protein expression vector. The Dectin-1 fusion protein expression vector is constructed successfully, Dectin-1 fusion protein with high purity is obtained after the Dectin-1 fusion protein expression vector is transfected to recipient cells, and the obtained soluble Dectin-1 fusion protein can be fixed on the metal surface of an SPR biosensor, thus fungi can be monitored quickly, quantitatively and flexibly in real time.

The invention relates to an angle modulation mechanism for modularization of an optical SPR (surface plasma resonance) biosensor. The angle modulation mechanism comprises a chip module, a laser regulating unit, a CCD (charge coupled device) regulating unit and a rack; wherein the laser regulating unit comprises a semi-circle card, an arm swinging frame, an idler wheel and a sliding rail, the arm swinging frame is movably installed on the rack by means of a rotation shaft, the semi-circle card is installed on the arm swinging frame, the idler wheel is installed at a lower side of the arm swinging frame and cooperates with the sliding rail which is arranged below the arm swinging frame to regulate a swinging angle of the arm swinging frame; a corresponding optical path detection channel is formed between laser, a chip component and a CCD image sensor. The angle modulation mechanism is delicate in structure, location is accurate, consistency regulation of an optical path is convenient; tightness of a pressure between a microflow pool and the chip module is convenient to regulate, so that the microflow pool is in close contact with an Au film, so as to not only prevent leakage of a sample solution but also prevent the Au film being damaged due to an excessive pressure; and furthermore, the microflow pool is convenient to ascend, and after the microflow pool is ascended and reset, accurate location between the microflow pool and a biological chip can be kept.

A surface plasmon resonance biosensor device and system are provided. The simplicity of SPR biosensor design allows easy integration with both QCM and electrochemistry techniques, not found in current SPR biosensor devices. In some embodiments, the surface plasmon resonance biosensor device has a dual SPR / QCM sample holder which allows simultaneous detection by both surface plasmon resonance and also quartz crystal microbalance (QCM) techniques. In additional embodiments, the surface plasmon resonance biosensor device and / or the dual SPR / QCM technique can be integrated with electrochemistry techniques by incorporate reference and counter electrodes in the SPR or SPR / QCM sample holder. Methods of using the device and system to determine whether an analyte of interest is present in a sample are also provided.

The invention provides a highly-sensitive infrared band SPR biosensor, and belongs to the technical field of biologic sensing. A halogen tungsten lamp provides a broadband light source, a multi-mode optical fiber is adopted to transmit lights, the lights are transmitted to a prism coated with a metal film by using a collimating lens in order to generate an SPR effect, an output optical signal is input to a computer through a spectrometer, and a compiled software program is used to process, analyze and store experiment data. a method disclosed in the invention greatly increases the sensitivity of a sensing system, and the sensitivity to an SPR signal with the wavelength in an infrared band is one order of magnitude higher than the sensitivity to an SPR signal with the wavelength in a visible band. A prism SPR sensing element adopted in the invention has good real-time responsiveness and stability, so the biosensor realizes high-sensitivity, high-resolution and high-precision detection, and can be used in real-time rapid detection of the characteristics of micro-concentration proteins, biological micro-molecules and cells.

The present invention provides a fiber SPR biosensor and a preparation method thereof. A sensing structure of molybdenum disulfide-gold film interlayer based on U-type fiber is used for the sensor. Acentral curved portion of the U-type fiber is a sensing area. A molybdenum disulfide coating is coated on a sensing area fiber surface. A gold film layer is coated on a surface of the molybdenum disulfide coating. Antibodies are fixed on a gold film surface by using dopamine. According to the SPR biosensor provided in the present invention, a fiber-molybdenum disulfide-gold film interlayer structure is used. Molybdenum disulfide has a greater band gap and higher light absorption efficiency, can stimulate a stronger SPR effect and enhance a surface field of the sensor, and can effectively improve sensitivity of the sensor. Antibodies are fixed on a sensor surface by using dopamine. Measurement with high antigen sensitivity and a low detection limit is implemented, so that the sensor is applied more widely in the biological detection aspect.

The invention provides an ITO-based laminated SPR biosensor chip, which comprises a glass substrate, a silver layer, an ITO layer and a gold layer which are sequentially arranged, the glass substrate is made of a BK7 material with high refractive index, the thickness of the glass substrate is about 1mm, the thickness of the silver layer is between 10nm and 30nm, the thickness of the ITO layer is between 20nm and 50nm, and the thickness of the gold layer is between 5nm and 20nm. According to the invention, the problem that preparation and coating are difficult to control when graphene is used as a sensitizing material can be avoided, so that a relatively mature semiconductor material ITO is turned to, and the preparation cost of a high-sensitivity chip is reduced; by means of the conductivity of ITO and the performance of a semiconductor, the chip has higher sensitivity; and the outermost gold layer can play a role in protecting the ITO from mildewing.